Unlocking High-Quality Teaching

The quality of the subject content taught in schools and settings plays a foundational role for students’ outcomes. It is important to emphasise that what students are learning must be of a high quality, or the quality of pedagogy is immaterial. Hence, it is not enough for students to be learning just something: what they are learning must be of a high quality.

Subject content includes both building a deep understanding around propositional knowledge (information and facts that can be captured and expressed in spoken or written sentences) and ways of doing subjects (including explicit procedures and wider tacit knowledge). It also encompasses students working with connections, patterns and generalisations in the content, and across content. To support this deep understanding of the content, teachers ensure that there are high levels of clarity and accuracy in student learning, and that content is carefully sequenced to be coherent. In this respect, teachers need to carefully consider both the question of what is being taught – working with the context of the curriculum – and how it is being taught.

The relationship between what students are taught and the success of their education is widely assumed across research and practice. Hence, the area of quality subject content is often an assumed dimension of teaching that is implicit in other studies of outcomes and effectiveness (Mejía‐Rodríguez and Kyriakides, 2022[1]) rather than operating as the primary focus. This means that the evidence this dimension draws upon is more disparate, as there is not a coherent, self-defined body of research on the concept of ‘Quality Subject Content’.

In terms of student outcomes, reviews of effective teaching have identified the importance of the quality of the subject content that students encounter. This is often focused on the knowledge of the teacher. Coe and colleagues’ (2014[2]) major review placed pedagogical content knowledge as their number one feature of effective pedagogy, citing the importance of teachers having ‘deep knowledge of the subjects they teach’ (p. 2[2]) to help their students to learn more, teachers should ‘understand the content they are teaching and how it is learnt’ (p. 5[2]).

Another relevant field of research here has been that into what is often referred to as ‘opportunities to learn’ (OTL), which refers to the subject matter as it is taught and experienced by students (OECD, 2020[5]). This centres on the idea that what is mandated in a curriculum is moulded by school- and teacher-level decision-making to create an implemented curriculum. This implemented curriculum may differ from the intended curriculum and thus translate into different opportunities to learn for students (Travers and Westbury, 1989[6]). OTL have been found to be a powerful determinant of students’ achievement growth (Kuger et al., 2017[7]; Burstein, 1993[8]), as well as their performance in international assessments (Scheerens, 2017[9]; Schmidt and  Maier, 2009[10]). Indeed, such opportunities can have a large impact on student achievement both within and between countries (Stacey and Turner, 2015[11]; OECD, 2010[12]).

The pedagogical choices of teachers play an important role in shaping learning opportunities and the content students encounter. Accordingly, these choices also influence students’ wider perception of a subject and, more broadly, knowledge that they develop. To foster quality subject content, teachers can make use of the following core practices:

• crafting explanations and expositions

• clarity, accuracy and coherence

• making connections

• nature of the subject.

All of these practices are important and inter-connected, and teachers might draw upon them simultaneously. High levels of clarity, accuracy and coherence are an underpinning feature of quality subject content. This guides how and when teachers craft explanations and expositions that move student understanding forward in a structured and accessible manner. Teachers engage students in going deeper and wider into the subject matter by examining the nature of the subject and making connections. These build a deeper, richer understanding as well as igniting students' own curiosity to explore further.

Each of these practices are outlined one-by-one below. Each section presents a definition for the practice and other associated terms on how it might also be referred to; key research findings on its impact on student outcomes; main implementation challenges identified by researchers and schools in designing the structure of the activity, task or content, role of students and role of teachers. Then, it looks into the complexity for teachers in monitoring them in the classroom. The final section builds on schools’ insights to provide an indication about the complexities of implementation and provides reflection questions for instructional and school leaders.

There are opportunities for detailed explanations and expositions of ideas or procedures. These are coherent and focused on the deeper features of the topic, including addressing the rationale behind the features of the explanation and how it connects to prior learning. They aim to move students towards being able to meaningfully apply particular ideas or procedures.

The teacher may provide written and/or verbal explanations of what is to be learned or may facilitate students providing explanations. To support students' engagement with explanations, the teacher may make use of modelling or scaffolds to make specific methods or steps clearer.

Associated Terms: Explaining; Instructing; Explicit procedures and processes; Scaffolding; Modelling or demonstrating; Presenting and communicating new ideas

The explaining or exposition of content are important parts of classroom interaction (Lachner, Weinhuber and Nückles, 2019[13]). They are a central element of teachers introducing new content to students. As Coe and colleagues (2020[14]) note in their review of research studies and frameworks relating to teacher effectiveness, the presentation of ideas in a clear and well-structured manner is a common feature of several evidence-based frameworks (e.g. Muijs et al., 2018_[15]; van de Grift et al., 2016_[16]).

There is evidence that detailed, explicit explanations by teachers of the ideas and processes can support students’ learning of the subject matter (Stockard et al., 2018[15]). This is paralleled by research that worked examples, such as through so-called modelling, can benefit students when meeting new ideas (Sweller, van Merriënboer and Paas, 2019[16]; Bokosmaty, Sweller and Kalyuga, 2015[17]; Atkinson et al., 2000[18]; Booth et al., 2015[19]). In particular, this process of thinking out loud that occurs through modelling is relevant for students’ understanding of how to engage in these deep and detailed thinking processes themselves. Similar ideas have also been described in relation to heuristics (Klauer and Phye, 2008[20]): explaining how problem-solving strategies work, or mental ‘shortcuts’ that can help with decision-making, can empower students to think across contexts and beyond a specific question or problem. Indeed, building understanding on the underpinning procedures and methods of the subject matter is also significant for students’ metacognitive abilities, as students come to not only learn something about the subject, but also learn how to learn more about it (Education Endowment Foundation, 2020[21]).

Students are not always equally disposed to engaging in high-quality explanations (Erath et al., 2018[22]). It is important that teachers are mindful of how they support students to engage with new content in a manageable way which challenges students but does not confuse them. Teachers need to consider the content of the explanation, such as the cognitive load it demands and how the information is broken down to align with students’ working memories (Sweller, van Merriënboer and Paas, 2019[16]). It is also a question of considering how the content is presented and communicated so that it is clear and comprehensible to students, avoiding superfluous information that may distract or confuse (Coe et al., 2020[14]).

Insights from schools:

Model a live explanation to students in real-time, especially with new content, where they are walked through the explanation step-by-step at an appropriate pace.

Break an explanation into clear, organised chunks, stopping and pausing to take either questions or to let students practise trying this first chunk on their own or in groups. For some content, the explanation should steadily progress adding new layers onto students’ understanding.

Build a class glossary of key terms for new vocabulary so students are explicitly introduced to technical language in the subject.

Use artefacts or concrete representations that bring an explanation to life and anchor what is being talked about, such as physical models that can be manipulated or examples that can illustrate a certain idea.

Students can also play an active role in shaping explanations. This gives students an opportunity to practise articulating their thinking and rationales, a type of deep thinking that can be beneficial for learning (Dunlosky et al., 2013[23]), notably for students with a range of attainment levels (Webb et al., 2021[24]).

Researchers have explored different approaches for encouraging this type of participation, in particular around the idea of students re-voicing contributions to be further refined to move the dialogue towards a fuller, more elaborate explanation (Moschkovich, 2002[25]; O’Connor and Michaels, 1993[26]).

Insights from schools:

Ask one student to write out the explanation and the other students to take on the role of speaking out the rationale for the explanation’s step while their peer is writing, this way the class are asked to essentially provide a commentary on why their peer is writing certain steps.

Call upon a range of students to build an explanation step-by-step, essentially passing the responsibility around the room to build a ‘whole-class’ example at the front.

Demonstrate student work through photos, videos or a live visualisation, for instance showing a model paragraph or a solution to a question where their own hand-written work can serve as a prompt for different students to analyse and explain specific features or steps. This can also demonstrate and celebrate what is possible.

Plan for a clear progression such as the “I do, we do, you do”, so that the learning moves away from copying what the teacher is doing to more independence of thought and practise.

Explanations help students develop an understanding of why a procedure or method is logical (OECD, 2020[5]) which then can help them to use and apply it to new scenarios. Researchers have argued that students benefit from making sense of individual steps in a mathematical procedure or methods (Mishra and Koehler, 2006[27]; Nunokawa, 2010[28]; Ball, 1988[29]). This echoes research in other subjects on making clear to students the rationale behind the tools and procedures that experts in that subject use, such as the ways of thinking of a historian (VanSledright, 2010[30]; Wineburg, 2001[31]) or a writer (Graham, Harris and Santangelo, 2015[32]).

Insights from schools:

Highlight the rationale of procedures clearly for students using annotations, whether in a written or verbal format, such as explicitly writing or saying “I am doing this step because…”

Expect students to include the rationale of steps, particularly when only in the early stages of working with new content. Students could write out the ‘why’ of key steps or speak this out with their peers.

Model examples that have increasingly complex real-world contexts when students are ready, so they can see how a particular explanation applies to a more complex example and how previous information is translated over.

The teaching presents ideas, concepts, tasks and teaching in a clear and coherent manner that is logical for the students to follow.

To support this clarity of understanding, the teaching creates opportunities for students to practise retrieving, using and adapting their knowledge and skills in increasingly variable and complex ways.

The teaching is accurate and free from unintentional or unaddressed errors, and there are no instances of confusion left unaddressed.

Associated Terms: Presentation of content; Sequencing of content; Practice opportunities; Addressing misconceptions; Rephrasing; Summaries and plenaries; Retrieval; Mastery and embedding

Reviews and models of effective teaching have consistently found clear, accurate and coherent teaching to be important classroom features (Coe et al., 2020[14]). Research drawing upon student-reported engagement and their perception of teachers’ practices has highlighted that teachers’ use of practices supporting a well-structured environment are associated with students’ behavioural, cognitive and emotional engagement (Hospel and Galand, 2016[33]).

In particular, presenting information in a clear, accurate and coherent manner helps students to build more accurate ‘schema’ and to avoid picking up errors (McVee, Dunsmore and Gavelek, 2005[34]). The concept of ‘schema’ is significant; schemas are “a pattern of thought that organises categories of information, and the links between them”, and which are stored in the long-term memory” (Education Endowment Foundation, 2021a, p. 49[35]). Developing this more accurate schema contributes to a virtuous cycle in which it is easier for students to critically evaluate and avoid other misconceptions and errors (e.g. Blastland and Dilnot (2008[36]).

This is part of a broader goal of building a high amount of quality knowledge schema, with a range of different studies showing that students with a high amount of knowledge tend to be able to undertake more complex tasks (Willingham, 2009[37]). This is related to understanding the gradual nature of the development of lasting memories, or memory consolidation (McGaugh, 2000[38]), with two particular areas of research important here in terms of teachers’ coherent sequencing of content. First, things can be forgotten and lost if they are not used, and thus schema need to be retrieved and used to build mental structures in the long-term memory, but without overwhelming students and impairing performance (Centre for Education Statistics and Evaluation, 2017[39]). Secondly, making aspects of retrieval or using knowledge more ‘automatic’ can enable the completion of more complex tasks with particular knowledge (Sweller, van Merrienboer and Paas, 1998[40]).

Prior learning is essential to future learning, and that means that researchers have been interested in how best to activate prior learning. One question has been how to space out the opportunities students have to practise using prior learning again. Students may retain ideas better in their long-term memory if they have a carefully spaced gap between opportunities to retrieve and use prior knowledge (Rogers and Thomas, 2022[41]). This seems to be more effective than just asking students to practise in consecutive days. This is linked to research on the idea of creating what researchers call ‘desirable difficulties’; if students have to work hard to retrieve something from their long-term memory, this can help to create a stronger connection in their schema (Willingham, 2009[37]).

Notably, this is connected to a further body of research around how topics may be recalled by encouraging students to practise a mix of problems and tasks, rather than practising the same topic problems in a blocked, sequential manner. Often referred to as ‘interleaving’ there have been some promising results (Patel, Liu and Koedinger, 2016[42]; Rohrer, Dedrick and Stershic, 2015[43]), though empirical work in typical classroom settings remains nascent and in need of further exploration.

Insights from schools:

Open the lesson with a starter activity that revisits a previous topic, which can kick students’ brains into gear by practising reusing their previous learning, but also serve as a routine, calm start to the lesson.

Consider revisiting a mix of themes from their previous learning – one that was recent, one a bit older, and one from further back – so they move between the topics and practise several different topics.

Collaborate with colleagues on a ‘school topic calendar’ so everyone can consider how they can revisit certain content or skills that others have been working on. If geography lessons are using statistics and last week mathematics lessons looked at percentages, how can the former strengthen the techniques students have been using in mathematics?

What do students want to revisit and work on? A quick anonymous survey of ‘two things from the last month you are unsure on’ can flag what the teacher might need to integrate into the sequencing.

Teachers’ decisions around how to sequence content shape the type of practice opportunities and mental connections students build. One area of research has focused on sequencing content for practice but progression too. Often referred to as ‘variation theory’, this body of work argues that rather than students simply repeating the same subject processes automatically, there should be planned, subtle variations that invite students to think critically about specific content they are considering. Studies have demonstrated the potential value of such approaches to contribute to student learning outcomes (Pang, 2003[44]; Runesson, 2005[45]). Research has primarily concentrated on mathematics, particularly in certain contexts like China and Singapore (Gu, Huang and Gu, 2017[46]; Ling, Chik and Pang, 2006[47]), though theoretical connections have been drawn more widely and there are some case studies in the teaching of drama and science (Lo and Marton, 2011[48]; Nilsson, 2014[49]).

Insights from schools:

Ensure there is some early success for students within the first stages of a topic or lesson before progressing to any variations. Even if small, it helps to build in an opportunity for students, particularly those less self-confident, to feel some progress and ready for a degree of variation with more challenge.

Vary one feature in different ways and keep the others constant, such as sentence starters (e.g. however, similarly) or one part of a formula in maths and sciences.

Present variations next to each other for comparison, such as the same sentence with different punctuation or tenses, or a number or function varying in an equation, so students can look across these clearly. Can students try and come up with their own example too?

The use of clear and deep periodic summaries has been conceptualised as an important feature of well-structured classrooms (Seidel, Rimmele and Prenzel, 2005[50]). The explicitness and clarity of the summary is particularly important (OECD, 2020[5]). Summaries and plenaries may occur at any point in a lesson, serving as an opportunity to review and summarise what has been learned. Plenaries are typically associated with the end of a lesson as an opportunity to formatively assess what has been learned. There is a growing body of recent research on how this type of small, informal and low-stakes ‘testing’ may be beneficial for students’ long-term retention of knowledge (Adesope, Trevisan and Sundararajan, 2017[51]). This points to the fact that summaries and plenaries, are more than simply short lists of points to be read at the end of a lesson, but they can demand students meaningfully think and use what they are learning.

Insights from schools:

Give enough time to plenaries so that students do not feel frustrated and pressured, which may hinder them from showing their real learning level and consequently be of little use to the teacher as a measure of their learning.

Use a variety of formats to avoid too much repetition when it comes to providing summaries, particularly as this may prompt students to translate their knowledge into a different representation.

Challenge students to develop their own summary points first on their own or in groups, and then come together as a class to build a ‘final summary’ that contains all of the essential information to be taken away.

A class ‘learning wall’ can be built over the course of lessons, composed of short summaries of all the major learnings from the lessons. Each student writes their summary and some of these can be added to the wall as students move onto a new topic.

Provide a handout of a student summary for students’ reference on each topic; if there is information that is really essential to learn and master – such as procedures or methods – then after summarising this as a class an example from a student could be chosen for distribution.

There are opportunities to explore and examine the connections that exist in and between subject matter ideas, procedures, perspectives, representations, and experiments. Connections should be explicit, detailed and ‘elaborate’ to help deepen student understanding, whilst always connecting to what has been previously learnt to ensure coherence.

This may also include students making connections between particular patterns in the content and more challenging abstractions; students may be pushed to make connections that encourage them to generalise from specific examples to broader foundational concepts or definitions.

Students are also encouraged to proactively make these kinds of connections within and between the otherwise discrete subjects that they are learning.

Associated Terms: Connecting to prior knowledge/learning; Connecting topics; Patterns and generalisations; Abstractions; Interdisciplinary thinking

Across a range of subjects and contexts, making connections has been shown to be a fundamental aspect of learning, including connections between specific words (Nunes, Bryant and Barros, 2012[52]), and connections between ideas, including as part of building internal mental structures or schema (Centre for Education Statistics and Evaluation, 2017[39]; Education Endowment Foundation, 2021a[35]; McVee, Dunsmore and Gavelek, 2005[34]). In particular, the ability to make clear, specific and explicit connections between ideas in the subject matter has been understood as a key feature of students developing a deeper understanding of the subject (Stigler and Hiebert, 1999[53]).

There has been particular interest in recent years in the field of cognitive science and trying to understand more about the processes of student learning. A recent systematic review of cognitive science approaches in the classroom found some support for the importance and efficacy of making connections in the classroom (Education Endowment Foundation, 2021a[35]). Evidence from the field of neuroscience also echoes these claims from a different perspective, arguing that making connections between different types of materials, sources and contexts also functions to drive biological changes in the brain through creating new neural connections which in turn builds capacity supporting further learning and recall (Owens and Tanner, 2017[54]). At the same time, there is also need for some caution; making connections demands careful monitoring and consideration, with it also having the potential to cause cognitive overload and be a negative experience for students if they are insufficiently familiar with the content (Education Endowment Foundation, 2021a[35]), pointing to the importance of understanding more about how making connections can be most effective in relation to students’ prior knowledge. Similarly, there is a need for more studies in typical classroom contexts. There remains though the potential for the field to yield findings going forward that are highly applicable across contexts (Education Endowment Foundation, 2021b, p. 5[55]).

Representing connections in ways that are tangible can support students’ comprehension of connections as well as their longer-term retention of this. One notable area of research has related to the use of physical and virtual manipulatives (Moyer-Packenham and Westenskow, 2013[56]), which can have positive effects on student learning though seemingly also demand teachers adopt a contextualised approach informed by student needs (Cooper, Sidney and Alibali, 2017[57]). Teachers may also draw upon narratives, with stories being described as ‘psychologically privileged’ (Willingham, 2004[58]) in part because of the way the form makes connections between information. Mar et al.’s (2021[59]) meta-analysis of the impacts on memory and comprehension related to the use of two types of texts (narrative and expository), leads them to conclude that stories are more readily understood, and also better remembered, than essays.

Insights from schools:

Use flashcards or puzzle pieces that can help students experiment and represent content, such as creating timelines of events or manipulating words and numbers in expressions.

Turn propositional information into stories and narratives, such as by bringing in themes of settings, plot and resolution; for instance, accounts of geographical places can become a sequential journey.

Demonstrate ‘real-time’ changes through software, such as to model the changes of state or different equations of motion in science.

Students can also play an active role in making connections in the content matter, as well as between different pieces of content. One area of particular research here has been engaging students in ‘mapping’, which has shown some promise as a useful approach in a range of contexts (Education Endowment Foundation, 2021a[35]; Gómez Betancur and King, 2014[60]). Sometimes referred to as ‘knowledge’, ‘concept’ or ‘mind’ mapping, the essential activity involves students writing or drawing aspects of the subject matter (e.g. terms, concepts, theories), linking them to show relevant connections that exist, and – crucially – explaining or summarising what the rationale is for the connections. It is important that this takes account of students’ prior knowledge and that there is a degree of student familiarity with the material for it to be productive, whilst some teacher guidance may also be needed to help ensure actual engagement with the content rather than surface-level organising of material (Hattan, Alexander and Lupo, 2023[61]; Education Endowment Foundation, 2021a[35]).

Insights from schools:

Seeing a concept map as an evolving log of their learning can help students identify new connections and build a deeper picture. For instance, revisiting maps to add in recent learning can add an extra layer of learning and mean new connections may be identified.

Create space for discussing and justifying connections, such as students providing peer feedback on others’ concept maps and asking each other to explain ‘why’ a connection exists.

One feature of making connections is progressing to identify patterns across connections to make generalisations and abstractions from these connections. Across subject areas, this process of wider connection-making and generalisation is an important part of quality subject matter, even if this may look different across subjects (Ball, 1988[29]; Henningsen and Stein, 1997[62]). Teachers can play a role in facilitating this process, with research have documented approaches such as the use of manipulatives in mathematics (Carbonneau, Marley and Selig, 2013[63]) or frameworks for evidence-use and argumentation in science (Shemwell et al., 2015[64]).

Insights from schools:

Encourage students to anticipate what the key concepts or outcomes will be and then self-assess their predictions at the end of the instruction or demonstration. While relying heavily on their prior knowledge, this method of prediction encourages them to question and understand why a generalisation they made did or didn’t work in that specific case.

Challenge students to re-organise their thinking, such as by redrafting an existing concept map into a new format – they might find new categories to organise things by, and new patterns that exist.

Create a space for students to ‘look across’ group projects or inquiries, such as when listening to other groups present their work, students note down similarities and differences across groups’ different focuses which can facilitate a whole-class discussion.

There are opportunities to consider the nature of the subject as students engage with the content. This focuses on considering the methods and processes that build disciplinary knowledge in a particular subject. There may be opportunities to consider the types of knowledge that are valued, the role of people in these processes, and the ideas and questions central to a subject.

Associated Terms: Disciplinary knowledge; Disciplinary thinking; Communicating purpose; Subject vocabulary

There is a long history of interrogating the question of what students are being asked to learn (Segall, 1999[65]; Graziano, 2008[66]). In recent years this has seen renewed attention, both from researchers and policy-makers (Mork et al., 2022[67]; Ioannidou and Erduran, 2022[68]); in the face of renewed global challenges that foreground questions around uncertainty (e.g. Lewandowsky, Ballard and Pancost, 2015_[71]); questions of equity including who and what types of knowledge are valued (e.g. Ladson-Billings, 2021_[72]); and demands for greater skills such as critical thinking in relation to engaging with subject matter (e.g. Scheie, Haug and Erduran, 2022_[73]).

There has been particularly rich growth in science education around the nature of science (Erduran and Dagher, 2014[69]). Understanding the nature of science and the epistemic ideas that underpin the subject is viewed as a fundamental part of scientific literacy (Lederman et al., 2013[70]). Small-scale empirical work with teachers has suggested that engaging with learning about the nature of science can support teachers’ pedagogy and impact students’ understanding of scientific processes including scientify inquiry (Khishfe, 2007[71]; Khishfe, 2013[72]). Similarly, research on inquiry activities linked to subject content suggests they can make aspects of the nature of science more meaningful to students, supporting students to think critically about the development of scientific knowledge as a human activity (Liu and Lederman, 2002[73]; Chinn and Malhotra, 2002[74]). More broadly, researchers in different fields have drawn attention to the importance of developing students’ understanding of the epistemic ideas in their subjects (e.g. Stoel, Logtenberg and Nitsche, 2022_[79]) and examined subject-specific procedures for building knowledge, such as historical reasoning (Gestsdottir, Van Drie and Van Boxtel, 2021[75]), or proof in mathematics (Sommerhoff and Ufer, 2019[76]).

There is still a need for more large-scale empirical studies across various fields and the synthesis of their findings to improve classroom implementation, which remains a considerable challenge. Translating knowledge and findings across different subjects is complex, and while social and institutional aspects, such as what counts as knowledge and which sources are trustworthy, are considered across subjects, they are not always coherently conceptualised as the 'nature of the subject’. Some subjects are only beginning to critically examine how knowledge is produced and refined within their fields (Puttick and Cullinane, 2021[77]). Researchers have already noted the existing tensions between teaching aspects relating to the nature of science and the curriculum (Lederman and Lederman, 2019[78]).

Presenting the big ideas and questions in the subject may help build what is sometimes referred to as ‘cultural capital’ in the subject. If the nature of the subject is understood as the ‘rules of the game’ (what counts as knowledge, who is seen as legitimate, and so on), there are strong arguments linking socio-economic background to greater familiarity with the rules of academic knowledge (Chisholm, 2021[79]; Broer, Bai and Fonseca, 2019[80]). Accordingly, it can be valuable to make what can be hidden assumptions about the nature of subjects more explicit. For instance, this has been suggested in research on argumentation in science (Osborne et al., 2019[81]; Kind and Osborne, 2016[82]) and proof in mathematics (Sommerhoff and Ufer, 2019[76]). This connects to wider research documenting that explicit introductions to and explanations of new ideas are an important aspect of teaching more widely (Bokosmaty, Sweller and Kalyuga, 2015[17]; Atkinson et al., 2000[18]).

Insights from schools:

Run a class investigation into the history of a subject to help highlight how knowledge has been built, which can also be a platform for discussing the strengths and weaknesses, such as biases, in this.

Include the story behind new content when introducing it, even if briefly, to bring in the wider context – who came up with this model, this theory, this argument, and why has it been important?

Set the ‘big question’ up for the students to debate. They often have a view on certain content, and at the end of a module could try and weigh in on the question – such as the cause of a historical event, or the purpose of certain characters in a text.

Bring in the limits of knowledge and unanswered questions in the field, these ongoing debates or mysteries often connect to the content and can be a way of showing how subjects are ‘still alive’.

Developing an understanding of the subject processes that build knowledge can take time, but students can be scaffolded to develop the critical judgement that characterises subject experts. In the field of history, Reisman (2012[83]) demonstrates how the use of primary sources and engaging with these in similar ways to a historian impacted students’ historical thinking and mastery of factual knowledge, with some skills being able to be applied to contemporary issues too. Part of the critical eye that students may develop may also include the question of uncertainty, and the limits of particular knowledge.

Insights from schools:

Role play subject- specific processes, like a student scientist having to justify their findings to the class, or students interrogating historical figures in a mock court of law.

Train students in using a clear questioning model for interrogating subject evidence as if an expert – for instance, what are the frequent questions a historian asks of a source, or a mathematician of a proof, or a writer of a paragraph?

Considering the nature of the subject can also be a consideration of equity and inclusion. Subjects may have a ‘canon’ of accepted figures that have helped to build the subject and are who students study today. Some students, particularly disadvantaged students and marginalised communities, may not see themselves reflected in a certain subject (Atkins et al., 2020[84]; Kricorian et al., 2020[85]). It may also encourage stereotypes, for instance that only some people can be mathematicians or musicians (Hadjar and Aeschlimann, 2014[86]; Jaoul‐Grammare, 2023[87]; Makarova, Aeschlimann and Herzog, 2019[88]). Accordingly, teachers may explicitly highlight the forces that have helped to build this canon and strive to ensure a diversity of figures in the subject, as demonstrated in research on highlighting the role of women in STEM (Science, Technology, Engineering and Mathematics) (Guenaga et al., 2022[89]; Hughes et al., 2020[90]), and ensuring a diversity of authors or historical figures in literacy and history (Epstein and Gist, 2013[91]; Mansfield, 2022[92]; Elliott et al., 2021[93]).

Insights from schools:

Seeing what people are doing currently, such as entrepreneurs, artists, scientists who have done something special in that subject, can be a way to bring different stories and people into a subject. These could be examples students find or ones proposed by the teacher.

Focus on the human side of role models or guest speakers, showing that these are ‘normal’ hard-working, passionate people that students can emulate.

Involve families in the learning process by inviting them to share their cultural traditions, stories, and expertise related to the subject matter.

Can students find the missing narrative? Students can make their voices heard by questioning and proposing the inclusion of more diverse authors, such as female authors in subjects like philosophy and science.

Sustaining high-quality subject content in the classroom is an ongoing process. It is one that requires monitoring and adaptation in the lesson as learning unfolds. It means that teachers are frequently looking for signals from students to gauge whether their implementation of teaching practices is effective or not. Teachers use their professional judgement in the classroom to perceive and process these signals.

Table 3.1 includes some of the key signals that teachers gather to check whether they have achieved the goal that they had intended when adopting that practice. The signals can be thought of as the short-term, in-class manifestation of the long-term knowledge, skills, values and attitudes that teachers seek to encourage.

• Knowledge: Teachers need to discern if students have a solid understanding of the content by recognising if they can explain their reasoning and connect ideas across subjects. This knowledge is robust and accurate, with students able to accurately recall what they have learnt and use it in new situations. Teachers to ensure that students have developed the ability to make increasingly elaborate but reasoned connections between their knowledge whilst also developing a holistic and comprehensive understanding of the topic itself.

• Skills: Teachers need to assess whether students can grasp the core of explanations to advance towards more complex and cognitively sophisticated learning. To do so, students need to be able to apply their learning to new situations and connect different content, whilst being able to self-monitor this process to identify potential errors. Teachers need to ensure students acquire the flexibility to apply their knowledge to different settings, being capable of asking questions to test their understanding and build on it.

• Values and attitudes: Teachers need to detect whether students feel their learning progress is solid enough to go further and use follow-up questions to explore new connections. It is key for teachers to know whether students feel they can use their knowledge to make their personal contributions to the field.

The teaching of quality subject content is shaped by the actions of the teacher in the classroom, but it is also influenced by broader actions at the school and system levels. A deeper exploration of the complexity of crafting quality subject content can shed light on ways in which leaders can create more supportive environments for teachers.

For example, classroom composition and professional collaboration can make a difference. It is complex for teachers to provide explanations and expositions for students with diverse learning profiles and varying levels of prior knowledge while minimizing the development of misconceptions. In this context, professional collaboration focused on specific subject issues can be beneficial. Teachers may need to be flexible in how they support students with content, whether in explaining underlying ideas or specific connections between content areas, and how they transfer the responsibility and agency to students to do this themselves. A space for collective professional refinement and reflection can help anticipate and address students’ misconceptions whilst ensuring that the content is clear, accurate, and coherent.

Another example is the flexibility of the curriculum and lesson timing, along with teachers' planning time. An overloaded curriculum can prevent teachers from achieving sufficient depth in their explanations and expositions. Additionally, the allocated lesson time may restrict how teachers revisit ideas, practice, and address misconceptions. The planning and sequencing of content are critical for knowledge retention and progression. It requires time and space for teachers to invest in, including collaboratively.

The school’s approach to using data to support teaching is also crucial, such as how it assists teachers in identifying areas where students struggle and need more explicit, remedial guidance. The complexity of monitoring students’ understanding in real-time during class is significant. Gaps may become particularly apparent as teachers help students make increasingly elaborate connections between content areas, and monitoring systems that can identify these gaps while providing opportunities to address them and build robust and accurate knowledge are critical.

To raise student interest, providing teachers with opportunities to develop a strong understanding of learners early on in the year, as well as opportunities to draw on resources beyond the school walls, might be beneficial. These can aid teachers in sparking class interest in epistemological questions related to the nature of the subject, rather than boring them. The school's resources and how these are allocated, as well as the school's connections with other learning environments in the community or beyond, can offer students opportunities not just to think like a scientist or historian but also to act as one.

In navigating the challenge of crafting quality subject content in classrooms, school and system leaders may carefully consider some of the following questions:

• How can school leaders create a whole-school approach to motivate students’ reflection around the most topical pressing questions in different curriculum subjects? What activities can be undertaken at the school level to contribute to helping students emulate experts in different fields of knowledge?

• What structures at the school level can support students to see the inter-connected nature of their learning?

• What kinds of professional development can help teachers refine how they make explanations and expositions of content, particularly that which is most complex and vulnerable to misconceptions? How could wider data and assessment inform this?

• What activities can be organised by the school beyond the classroom to develop the capacity of students to give explanations and articulate their reasoning? What kinds of real-world situations that require these skills could be modelled in schools for students to practice?

• How can high-level curricula goals be translated into coherent sequences of work that best build robust understanding of content throughout schooling? How can short-term needs be balanced with a long-term perspective on curricula too?

[51] Adesope, O., D. Trevisan and N. Sundararajan (2017), “Rethinking the Use of Tests: A Meta-Analysis of Practice Testing”, Review of Educational Research, Vol. 87/3, pp. 659-701, https://doi.org/10.3102/0034654316689306.

[84] Atkins, K. et al. (2020), ““Looking at Myself in the Future”: how mentoring shapes scientific identity for STEM students from underrepresented groups”, International Journal of STEM Education, Vol. 7/1, https://doi.org/10.1186/s40594-020-00242-3.

[18] Atkinson, R. et al. (2000), “Learning from Examples: Instructional Principles from the Worked Examples Research”, Review of Educational Research, Vol. 70/2, pp. 181-214, https://doi.org/10.3102/00346543070002181.

[29] Ball, D. (1988), Research on teaching mathematics: Making subject matter knowledge part of the equation.

[36] Blastland,  . and A. Dilnot (2008), The Tiger that Isn’t: Seeing through a world of numbers, Profile Books.

[17] Bokosmaty, S., J. Sweller and S. Kalyuga (2015), “Learning geometry problem solving by studying worked examples: Effects of learner guidance and expertise”, American Educational Research Journal, Vol. 52/2, pp. 307-333.

[19] Booth, J. et al. (2015), “Simple Practice Doesn’t Always Make Perfect”, Policy Insights from the Behavioral and Brain Sciences, Vol. 2/1, pp. 24-32, https://doi.org/10.1177/2372732215601691.

[4] Botturi, L. (2019), “Digital and media literacy in pre-service teachereducation”, Nordic Journal of Digital Literacy, Vol. 14/3-4, pp. 147-163, https://doi.org/10.18261/issn.1891-943x-2019-03-04-05.

[80] Broer, M., Y. Bai and F. Fonseca (2019), “Socioeconomic Inequality and Educational Outcomes: An Introduction”, in IEA Research for Education, Socioeconomic Inequality and Educational Outcomes, Springer International Publishing, Cham, https://doi.org/10.1007/978-3-030-11991-1_1.

[8] Burstein, L. (ed.) (1993), The IEA Study of Mathematics III: Student Growth and Classroom Processes, Pergamon.

[63] Carbonneau, K., S. Marley and J. Selig (2013), “A meta-analysis of the efficacy of teaching mathematics with concrete manipulatives”, Journal of Educational Psychology, Vol. 105/2, pp. 380-400.

[39] Centre for Education Statistics and Evaluation (2017), Cognitive Load Theory: Research that teachers really need to understand, http://www.cese.nsw.gov.au/images/stories/PDF/cognitive-load-theory-VR_AA3.pdf (accessed on 18 September  2023).

[74] Chinn, C. and B. Malhotra (2002), “Epistemologically authentic inquiry in schools: A theoretical framework for evaluating inquiry tasks”, Science Education, Vol. 86/2, pp. 175-218, https://doi.org/10.1002/sce.10001.

[79] Chisholm, L. (2021), RULES OF THE GAME FOR HIGH SCHOOL SUCCESS: HOW THEY ARE DEVELOPED, TRANSMITTED, AND REINFORCED, https://urbanedjournal.gse.upenn.edu (accessed on 13 August 2024).

[14] Coe, R. et al. (2020), Great Teaching Toolkit: Evidence Review, https://www.cambridgeinternational.org/Images/584543-great-teaching-toolkit-evidence-review.pdf (accessed on 18 September  2023).

[2] Coe, R. et al. (2014), What makes great teaching? Review of the underpinning research, https://www.suttontrust.com/our-research/great-teaching/ (accessed on 18 September  2023).

[57] Cooper, J., P. Sidney and M. Alibali (2017), “Who Benefits from Diagrams and Illustrtations in Math Problems? Ability and Attitudes Matter”, Applied Cognitive Psychology, Vol. 32/1, pp. 24-38.

[23] Dunlosky, J. et al. (2013), “Improving Students’ Learning With Effective Learning Techniques”, Psychological Science in the Public Interest, Vol. 14/1, pp. 4-58, https://doi.org/10.1177/1529100612453266.

[21] Education Endowment Foundation (2020), Early Years and Key Stage 1 Mathematics Teaching: Evidence Review, https://d2tic4wvo1iusb.cloudfront.net/production/documents/guidance/Early_Years_and_Key_Stage_1_Mathematics_Evidence_Review.pdf?v=1693992658 (accessed on 7 August 2024).

[35] Education Endowment Foundation (2021a), Cognitive Science Approaches in the Classroom: A Review of the Evidence, https://educationendowmentfoundation.org.uk/education-evidence/evidence-reviews/cognitive-science-approaches-in-the-classroom (accessed on 18 September  2023).

[55] Education Endowment Foundation (2021b), Cognitive Science Approaches in the Classroom: Protocol for a systematic review, https://d2tic4wvo1iusb.cloudfront.net/documents/guidance/EEF_Cog_Sci_Review_Protocol_final.pdf?v=1681211765 (accessed on 18 September  2023).

[93] Elliott, V. et al. (2021), Lit in colour: Diversity in literature in English schools, Penguin, https://litincolour. penguin. co.uk (accessed on 13 August 2024).

[91] Epstein, T. and C. Gist (2013), “Teaching racial literacy in secondary humanities classrooms: challenging adolescents’ of color concepts of race and racism”, Race Ethnicity and Education, Vol. 18/1, pp. 40-60, https://doi.org/10.1080/13613324.2013.792800.

[22] Erath, K. et al. (2018), “Discourse competence as important part of academic language proficiency in mathematics classrooms: the case of explaining to learn and learning to explain”, Educational Studies in Mathematics, Vol. 99/2, pp. 161-179, https://doi.org/10.1007/s10649-018-9830-7.

[69] Erduran, S. and Z. Dagher (2014), Reconceptualizing the Nature of Science for Science Education: Scientific Knowledge, Practices and Other Family Categories, Springer.

[75] Gestsdottir, S., J. Van Drie and C. Van Boxtel (2021), “Teaching historical thinking and reasoning: Teacher beliefs”, History Education Research Journal, Vol. 18/1, pp. 46-63.

[60] Gómez Betancur, M. and G. King (2014), “Uso de mapas mentales como método para ayudar a estudiantes de ESL/EFL a conectar vocabulario y conceptos en diferentes contextos”, trilogía Ciencia Tecnología Sociedad, Vol. 6/10, p. 69, https://doi.org/10.22430/21457778.439.

[32] Graham, S., K. Harris and T. Santangelo (2015), “Research-Based Writing Practices and the Common Core”, The Elementary School Journal, Vol. 115/4, pp. 498-522, https://doi.org/10.1086/681964.

[66] Graziano, K. (2008), “Walk the talk: Connecting critical pedagogy and practice in teacher education”, Teaching Education, Vol. 19/2, pp. 153-163, https://doi.org/10.1080/10476210802040740.

[89] Guenaga, M. et al. (2022), “The Impact of Female Role Models Leading a Group Mentoring Program to Promote STEM Vocations among Young Girls”, Sustainability, Vol. 14/3, p. 1420, https://doi.org/10.3390/su14031420.

[46] Gu, F., R. Huang and L. Gu (2017), “Theory and Development of Teaching Through Variation in Mathematics in China”, in Teaching and Learning Mathematics through Variation, SensePublishers, Rotterdam, https://doi.org/10.1007/978-94-6300-782-5_2.

[86] Hadjar, A. and B. Aeschlimann (2014), “Gender stereotypes and gendered vocational aspirations among Swiss secondary school students”, Educational Research, Vol. 57/1, pp. 22-42, https://doi.org/10.1080/00131881.2014.983719.

[61] Hattan, C., P. Alexander and S. Lupo (2023), “Leveraging What Students Know to Make Sense of Texts: What the Research Says About Prior Knowledge Activation”, Review of Educational Research, Vol. 94/1, pp. 73-111, https://doi.org/10.3102/00346543221148478.

[62] Henningsen, M. and M. Stein (1997), “Mathematical Tasks and Student Cognition: Classroom-Based Factors That Support and Inhibit High-Level Mathematical Thinking and Reasoning”, Journal for Research in Mathematics Education, Vol. 28/5, p. 524, https://doi.org/10.2307/749690.

[33] Hospel, V. and B. Galand (2016), “Are both classroom autonomy support and structure equally important for students’ engagement? A multilevel analysis”, Learning and Instruction.

[90] Hughes, R. et al. (2020), “A Summary of Effective Gender Equitable Teaching Practices in Informal STEM Education Spaces”, The Journal of STEM Outreach, Vol. 3/1, https://doi.org/10.15695/jstem/v3i1.16.

[68] Ioannidou, O. and S. Erduran (2022), “Policymakers’ Views of Future-Oriented Skills in Science Education”, Frontiers in Education, Vol. 7, https://doi.org/10.3389/feduc.2022.910128.

[87] Jaoul‐Grammare, M. (2023), “Gendered professions, prestigious professions: When stereotypes condition career choices”, European Journal of Education, Vol. 59/2, https://doi.org/10.1111/ejed.12603.

[72] Khishfe, R. (2013), “Explicit Nature of Science and Argumentation Instruction in the Context of Socioscientific Issues: An effect on student learning and transfer”, International Journal of Science Education, Vol. 36/6, pp. 974-1016, https://doi.org/10.1080/09500693.2013.832004.

[71] Khishfe, R. (2007), “The development of seventh graders’ views of nature of science”, Journal of Research in Science Teaching, Vol. 45/4, pp. 470-496, https://doi.org/10.1002/tea.20230.

[82] Kind, P. and J. Osborne (2016), “Styles of Scientific Reasoning: A Cultural Rationale for Science Education?”, Science Education, Vol. 101/1, pp. 8-31, https://doi.org/10.1002/sce.21251.

[20] Klauer, K. and G. Phye (2008), “Indictive Reasoning: A Training Approach”, Review of Educational Research, Vol. 78/1, pp. 85-123.

[85] Kricorian, K. et al. (2020), “Factors influencing participation of underrepresented students in STEM fields: matched mentors and mindsets”, International Journal of STEM Education, Vol. 7/1, https://doi.org/10.1186/s40594-020-00219-2.

[7] Kuger, S. et al. (2017), “Mathematikunterricht und Schülerleistung in der Sekundarstufe: Zur Validität von Schülerbefragungen in Schulleistungsstudien, Student learning in secondary school mathematics classrooms: On the validity of student reports in international large-scale studies”, Zeitschrift für Erziehungswissenschaft, Vol. 20/S2, pp. 61-98, https://doi.org/10.1007/s11618-017-0750-6.

[13] Lachner, A., M. Weinhuber and M. Nückles (2019), “To teach or not to teach the conceptual structure of mathematics? Teachers undervalue the potential of Principle-Oriented explanations”, Contemporary Educational Psychology, Vol. 58, pp. 175-185, https://doi.org/10.1016/j.cedpsych.2019.03.008.

[70] Lederman, J. et al. (2013), “Meaningful assessment of learners’ understandings about scientific inquiry-The views about scientific inquiry (VASI) questionnaire”, Journal of Research in Science Teaching, Vol. 51/1, pp. 65-83, https://doi.org/10.1002/tea.21125.

[78] Lederman, N. and J. Lederman (2019), “Teaching and Learning of Nature of Scientific Knowledge and Scientific Inquiry: Building Capacity through Systematic Research-Based Professional Development”, Journal of Science Teacher Education, Vol. 30/7, pp. 737-762, https://doi.org/10.1080/1046560x.2019.1625572.

[47] Ling, L., P. Chik and M. Pang (2006), “Patterns of Variation in Teaching the Colour of Light to Primary 3 Students”, Instructional Science, Vol. 34/1, pp. 1-19, https://doi.org/10.1007/s11251-005-3348-y.

[73] Liu, S. and N. Lederman (2002), “Taiwanese Gifted Students’ Views of Nature of Science”, School Science and Mathematics, Vol. 102/3, pp. 114-123, https://doi.org/10.1111/j.1949-8594.2002.tb17905.x.

[48] Lo, M. and F. Marton (2011), “Towards a science of the art of teaching”, International Journal for Lesson and Learning Studies, Vol. 1/1, pp. 7-22, https://doi.org/10.1108/20468251211179678.

[88] Makarova, E., B. Aeschlimann and W. Herzog (2019), “The Gender Gap in STEM Fields: The Impact of the Gender Stereotype of Math and Science on Secondary Students’ Career Aspirations”, Frontiers in Education, Vol. 4, https://doi.org/10.3389/feduc.2019.00060.

[92] Mansfield, A. (2022), “Increasing inclusion for ethnic minority students by teaching the British Empire and global history in the English history curriculum”, Oxford Review of Education, Vol. 49/3, pp. 360-375, https://doi.org/10.1080/03054985.2022.2087618.

[59] Mar, R. et al. (2021), “Memory and comprehension of narrative versus expository texts: A meta-analysis”, Psychonomic Bulletin & Review, Vol. 28/3, pp. 732-749, https://doi.org/10.3758/s13423-020-01853-1.

[38] McGaugh, J. (2000), “Memory – a Century of Consolidation”, Science, Vol. 287/5451, pp. 248-251.

[34] McVee, M., K. Dunsmore and J. Gavelek (2005), “Schema Theory Revisited”, Review of Educational Research, Vol. 75/4, pp. 531-566.

[1] Mejía‐Rodríguez, A. and L. Kyriakides (2022), “What matters for student learning outcomes? A systematic review of studies exploring system‐level factors of educational effectiveness”, Review of Education, Vol. 10/3, https://doi.org/10.1002/rev3.3374.

[27] Mishra, P. and M. Koehler (2006), “Technological pedagogical content knowledge: A framework for teacher knowledge”, Teachers College Record, pp. 1017-1054.

[67] Mork, S. et al. (2022), “Humanising the nature of science: an analysis of the science curriculum in Norway”, International Journal of Science Education, Vol. 44/10, pp. 1601-1618, https://doi.org/10.1080/09500693.2022.2088876.

[25] Moschkovich, J. (2002), “A situated and sociocultural perspective on bilingual mathematics learners”, Mathematical Thinking and Learning, Vol. 4/2 & 3, pp. 189-212.

[56] Moyer-Packenham, P. and A. Westenskow (2013), “Effects of Virtual Manipulatives on Student Achievement and Mathematics Learning”, International Journal of Virtual and Personal Learning Environments, Vol. 4/3, pp. 35-50.

[49] Nilsson, P. (2014), “When Teaching Makes a Difference: Developing science teachers’ pedagogical content knowledge through learning study”, International Journal of Science Education, Vol. 36/11, pp. 1794-1814, https://doi.org/10.1080/09500693.2013.879621.

[52] Nunes, T., P. Bryant and R. Barros (2012), “The development of word recognition and its significance for comprehension and fluency”, Journal of Educational Psychology, Vol. 104/4, pp. 959-973.

[28] Nunokawa, K. (2010), Proof, mathematical problem-solving, and explanation in mathematics teaching, Springer.

[26] O’Connor, M. and S. Michaels (1993), “Aligning academic task and participation status through revoicing: Analysis of a classroom discourse strategy”, Anthropology and Education Quarterly, Vol. 24/4, pp. 318-335.

[5] OECD (2020), Global Teaching InSights: A Video Study of Teaching, OECD Publishing, Paris, https://doi.org/10.1787/20d6f36b-en.

[12] OECD (2010), PISA 2009 Results: Overcoming Social Background: Equity in Learning Opportunities and Outcomes (Volume II), PISA, OECD Publishing, Paris, https://doi.org/10.1787/9789264091504-en.

[81] Osborne, J. et al. (2019), “Impacts of a Practice-Based Professional Development Program on Elementary Teachers’ Facilitation of and Student Engagement With Scientific Argumentation”, American Educational Research Journal, Vol. 56/4, pp. 1067-1112, https://doi.org/10.3102/0002831218812059.

[54] Owens, M. and K. Tanner (2017), “Teaching as Brain Changing: Exploring Connections between Neuroscience and Innovative Teaching”, CBE—Life Sciences Education, Vol. 16/2, p. fe2, https://doi.org/10.1187/cbe.17-01-0005.

[44] Pang, M. (2003), , Instructional Science, Vol. 31/3, pp. 175-194, https://doi.org/10.1023/a:1023280619632.

[42] Patel, R., R. Liu and K. Koedinger (2016), “When to Block versus Interleave Practice? Evidence Against Teaching Fraction Addition before Fraction Multiplication”, Cognitive Science.

[77] Puttick, S. and A. Cullinane (2021), “Towards the Nature of Geography for geograph education: an exploratory account, learning from work on the Nature of Science”, Journal of Geography in Higher Education, Vol. 46/3, pp. 343-359.

[83] Reisman, A. (2012), “Reading Like a Historian: A Document-Based History Curriculum Intervention in Urban High Schools”, Cognition and Instruction, Vol. 30/1, pp. 86-112, https://doi.org/10.1080/07370008.2011.634081.

[41] Rogers, C. and M. Thomas (2022), Educational Neuroscience, Routledge, London, https://doi.org/10.4324/9781003185642.

[43] Rohrer, D., R. Dedrick and S. Stershic (2015), “Interleaved practice improves mathematics learning.”, Journal of Educational Psychology, Vol. 107/3, pp. 900-908, https://doi.org/10.1037/edu0000001.

[45] Runesson, U. (2005), “Beyond discourse and interaction. Variation: a critical aspect for teaching and learning mathematics”, Cambridge Journal of Education, Vol. 35/1, pp. 69-87, https://doi.org/10.1080/0305764042000332506.

[9] Scheerens, J. (ed.) (2017), Opportunity to Learn, Curriculum Alignment and Test Preparation, Springer International Publishing, Cham, https://doi.org/10.1007/978-3-319-43110-9.

[65] Segall, A. (1999), “Critical History: Implications for History/Social Studies Education”, Theory & Research in Social Education, Vol. 27/3, pp. 358-374, https://doi.org/10.1080/00933104.1999.10505885.

[50] Seidel, T., R. Rimmele and M. Prenzel (2005), “Clarity and coherence of lesson goals as a scaffold for student learning”, Learning and Instruction, Vol. 15/6, pp. 539-556, https://doi.org/10.1016/j.learninstruc.2005.08.004.

[64] Shemwell, J. et al. (2015), “Supporting Teachers to Attend to Generalisation in Science Classroom Argumentation”, International Journal of Science Education, Vol. 37/4, pp. 599-628, https://doi.org/10.1080/09500693.2014.1000428.

[76] Sommerhoff, D. and S. Ufer (2019), “Acceptance criteria for validating mathematical proofs used by school students, university students, and mathematicians in the context of teaching”, ZDM Mathematics Education, Vol. 51, pp. 717-730.

[11] Stacey, K. and R. Turner (eds.) (2015), Assessing Mathematical Literacy, Springer International Publishing, Cham, https://doi.org/10.1007/978-3-319-10121-7.

[53] Stigler, J. and J. Hiebert (1999), The Teaching Gap: Best Ideas from the World’s Teachers for Improving Education in the Classroom, New York: The Free Press.

[15] Stockard, J. et al. (2018), “The Effectiveness of Direct Instruction Curricula: A Meta-Analysis of a Half Century of Research”, Review of Educational Research, Vol. 88/4, pp. 479-507, https://doi.org/10.3102/0034654317751919.

[40] Sweller, J., J. van Merrienboer and F. Paas (1998), , Educational Psychology Review, Vol. 10/3, pp. 251-296, https://doi.org/10.1023/a:1022193728205.

[16] Sweller, J., J. van Merriënboer and F. Paas (2019), “Cognitive Architecture and Instructional Design: 20 Years Later”, Educational Psychology Review, Vol. 31/2, pp. 261-292, https://doi.org/10.1007/s10648-019-09465-5.

[10] Sykes, G. (ed.) (2009), Opportunity to Learn, Routledge, Taylor & Francis Group.

[6] Travers, K. and I. Westbury (1989), “The IEA study of mathematics I: Analysis of mathematics curricula”, International studies in educational achievement, Vol. 1/4.

[30] VanSledright, B. (2010), The Challenge of Rethinking History Education, Routledge, https://doi.org/10.4324/9780203844847.

[3] Wadhwa, M., J. Zheng and T. Cook (2023), “How Consistent Are Meanings of “Evidence-Based”? A Comparative Review of 12 Clearinghouses that Rate the Effectiveness of Educational Programs”, Review of Educational Research, Vol. 94/1, pp. 3-32, https://doi.org/10.3102/00346543231152262.

[24] Webb, N. et al. (2021), “Is There a Right Way? Productive Patterns of Interaction during Collaborative Problem Solving”, Education Sciences, Vol. 11/5, p. 214, https://doi.org/10.3390/educsci11050214.

[37] Willingham, D. (2009), Why don’t students like school? A cognitive scientist answers questions about how the mind works and what it means for the classroom, Jossey-Bass/Wiley.

[58] Willingham, D. (2004), The Privileged Status of Story, http://www.aft.org/newspubs/periodicals/ae/summer2004/willingham.cfm (accessed on 18 September  2023).

[31] Wineburg, S. (2001), Historical Thinking and Other Unnatural Acts, Temple University Press.