GEReCo UK IGU-CGE

Geography Education Research Collective / UK Commission on Geographical Education of the International Geographical Union

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  • Winners announced! 2026 GEReCo Masters Dissertation Award

    We are delighted to announce the outcomes from the 2026 GEReCo Masters Dissertation Award! This annual award is designed to celebrate and amplify the voices of emerging researchers who are shaping the future of geography education.

    Many congratulations to Jack Downs  (MSc Learning and Teaching, University of Oxford) for being awarded the Winning dissertation prize for a thesis titled: An investigation into the impact of Artificial Intelligence on pupil engagement in Year 9 geography lessons.

    This is an exceptionally thorough, timely, and methodologically sound study. Investigating the intersection of Generative AI (GenAI) and classroom pedagogy, this dissertation offers an exploration of our rapidly evolving educational and technological landscape. Grounded in a critical realist framework, the researcher deployed a mixed-methods case study across nine Y9 lessons on tectonic hazards, incorporating Martin’s Motivation and Engagement Scale, pupil-voice questionnaires, teacher reflective logs, and semi-structured interviews. This study provided rich, real-world data showing that while GenAI can enhance motivation and visible participation through adaptive scaffolding and instant feedback, it can also lead to superficial cognitive engagement if pupils use it merely to obtain answers.

    The candidate demonstrated critical engagement with the literature, successfully synthesizing technology-enhanced learning with subject-specific geography pedagogy. The conclusions that “human interaction remained important for making sense of feedback and judging accuracy. In summary, pupils liked GenAI most when it was responsive, set within a clear framework and specifically connected to geography learning goals. They were wary when speed, choice overload or reliability concerns became more prominent” were interesting. It provides the geography education community with some replicable research design principles, useful success criteria, and a clear framework for (which is vital) training pupils to critically analyze AI outputs in the classroom.

    Many congratulations also to Harriet Bray  (MSc Learning and Teaching, University of Oxford) for the Highly Commended dissertation for a thesis titled: Global citizens: how can we better realise our department’s aim through curriculum design?

    This was a compelling, reflective, and contextually relevant discussion. It addresses a highly relevant issue in curriculum design, and the candidate used an established and sustained literature base to interrogate how their department’s stated aim of fostering “global citizens” was falling short of promoting active or critical citizenship. 


    Through an enquiry-led redesign of a Year 7 scheme of work (“How will Kenya close the development gap?”), the researcher embedded classroom votes, debates, and decision-making to allow students to critically confront historical and development discourses.

    While the study is limited in size and sections of the work remain primarily descriptive, the panel highly commends the researcher’s rigorous and honest critical analysis of their findings. By identifying that increased global awareness occurred predominantly among higher prior attaining students, and utilizing Andreotti’s (2006) framework to show how some students still reverted to a “soft” version of global citizenship rooted in charity rather than structural inequality, this work makes a vital, realistic contribution to geography curriculum policy and the ongoing debate surrounding critical global citizenship education. In conclusion, the investigator says that “Perhaps in the context of school Geography it is worth investigating what kinds of academic barriers might hinder students in their path to becoming global citizens. Quieter students were less likely to engage in class debates and less confident students were not as keen to participate in votes or to make decisions and justify them. The accessibility of global citizenship teaching is therefore something needing further investigation.” Much food for thought for the whole education community. 

    Look out for further information on both research projects, including through blog posts on the GEReCo site. 

    The 2027 GEReCo Masters Dissertation Award will open for submissions soon at https://www.gereco.org/about/gereco-masters-dissertation-award/

  • GEReCo Open Forum 2026: Standards in geography education over the last 30 years

    In this video Dr John Hopkin considers standards in geography education over the last 30 years, as part of the annual GGEReCo Open Forum.

    John explores how things have changed and, in some cases, stayed the same, before highlighting what this means for geography teaching today. Two respondents: Iram Sammar and Sarah Sprake bring their perspectives to the discussion. Read the GA National Research Report: Standards in school geography, 1991 – 2023

  • Geography Education Research Collective Annual Seminar

    Join the annual Geography Education Research Collection (GEReCo) open seminar to hear from Dr John Hopkin about standards in geography education over the last 30 years.

    John will explore how things have changed and, in some cases, stayed the same, before highlighting what this means for geography teaching today.

    Three respondents: Iram Sammar, Sarah Sprake and Steve Puttick will then bring their perspectives to the discussion.

    Read the GA National Research Report: Standards in school geography, 1991 – 2023 here.

    This session will take place on Monday 9 March between 4.00 and 5.30pm.

    Book here: https://portal.geography.org.uk/event/book/E000219

  • Call for chapters: Geography and Education: Concepts for re-imagining research, policy and practice

    Education is inherently geographical, and geography has made substantial contributions to education research, policy and practice. This edited collection showcases some of the key concepts shaping and enriching the field of geographies of education. The collection is deliberately written for education; it is intended for those studying and researching education to further explore and contribute to discourse about how geographies shape education spaces, processes, access and outcomes.   From spatial inequities in education attainment, to access to nature, to sites of education as targets in warfare and law, to the surveillance of children and teachers through building design and accountability measures, the collection comes at a time when many children, students, educators, researchers and policy makers are considering how and why geographies matter in, and to, education. The rich and growing field of research in geographies of education, and forms of spatial thinking more generally, have much to offer the discipline of education and the social sciences more broadly. 

    This book will actively and substantively support engagement with geography (as a disciplinary lens) and geographies in, and of, the world in education research, policy and practice. It will support work to promote the value of geographies of education research to undergraduate and postgraduate education programmes. Focused on key concepts in geography – including, but not limited to, space, place, environment, time, scale, justice and power – we invite chapters that examine how geographical ideas and methods can enhance our knowledges of, policies for, and practices in, education. The book will present multiple chapters (3 or 4) focused on the same concept. Each concept will be introduced by a brief commentary, signposting the main arguments and acting as a primer to the following chapters.

    This conceptual focus seeks to recognise and celebrate that education happens in, and is shaped by, place(s); that education spaces are often places of play, socialisation and counterculture, as well as teaching and (un)learning; and that geographical concepts, including space, can help us to better understand and challenge injustices at a variety of scales. Engagement with concepts including power and space can also support broader engagement with questions about how work in the field of geographies of education can enhance knowledge of how and why people, information, policies and ideas flow and evolve across time and space, in turn, shaping lives, places and practices through education.

    We invite contributions from colleagues researching in geographies of education and connected fields or working as an educator or policy maker with an interest in these matters. Chapters should be aimed primarily at an academic audience – including postgraduate students – with attention paid to how the arguments put forward can contribute to education research, policy and/or practice. Chapters may focus on any phase of education, consider education in different times or use a temporal lens, and engage with formal or alternative / non formal education in different places to engage with debates about key concepts in the geographies of education, including – but not limited to:

    • Space
    • Place
    • Environment
    • Time
    • Scale
    • Power
    • Justice

    Within these concepts, substantive areas of focus might be drawn from across the breath of research in the geographies of education, such as: Spatial (in)justices and education; The design of classrooms, schools or other education spaces; Children or educators’ experiences and imaginations of education and education spaces; Institutional geographies; Outdoor learning; Nature-connectedness; Historical geographies of education; Education and futures; Anti-fascist education; Or, methods for researching geographies in of education.

     Chapter formats include:

    • A 6000-word written contribution including references, including a 500-1000 word section on how the arguments put forward can contribute to education research methodologies, policy and/or practice.
    • A 6000-word discussion, including references, between multiple authors discussing their different perspectives on how, and why, geographies of education matter to education.
    • An artistic representation connected to geographies of education, with a short-written discussion.

    To submit your chapter, please email Dr Lauren Hammond lauren.hammond@education.ox.ac.uk by 30thJanuary 2026. Please include:

    • Name of author(s)
    • Any institutional affiliation(s)
    • The title of the chapter
    • A 200-word abstract, which clearly articulates how the ideas, knowledges or methods shared in the chapter contribute to research, policy and/or practice in education.
    • Type of chapter (e.g. 6000 word written contribution)
    • Which geographical concept(s) your chapter speaks to (e.g. time, space, place, power, environment, scale etc.)

    Edited by

    Lauren Hammond (Department of Education, University of Oxford; IOE, UCL’s Faculty of Education and Society)

    Matt Finn (Department of Geography, University of Exeter)

    Steve Puttick (Department of Education, University of Oxford) 

    William Quirke (Strathclyde Institute of Education, University of Strathclyde)

  • Winners announced! 2025 GEReCo Masters Dissertation Award

    We are delighted to announce the outcomes from the 2025 GEReCo Masters Dissertation Award! This annual award is designed to celebrate and amplify the voices of emerging researchers who are shaping the future of geography education.

    Many congratulations to Nona Anderson  (MSc Education, Power and Social Change, Birkbeck, University of London) for being awarded the Winning dissertation prize for a thesis titled: Is climate justice racial justice? A critical analysis of a GCSE Geography textbook.

    Nona’s research presents an argument that the ‘official’ geography curriculum can distort students’ geographical understanding by hiding the role played by political economy (carbon & colonial capitalism) in shaping the world. The research does so by critiquing a GCSE textbook chapter about climate change. Whilst there are other de-colonial critiques of school geography, this work is outstanding in how several lenses are brought to the critique and each is considered critically. These lenses include: Anthropocene/ Capitalocene; Powerful Knowledge/ knowledge of the powerful; Global North-South/ the abyssal line; and climate change science/ climate and racial justice. Scholarship and use of literature to build the argument is excellent and is well-supported by the deconstruction of a textbook chapter. The author’s voice is strong and clear throughout, and this dissertation makes a compelling case for revising versions of ‘official curriculum’ that hide important causes of global problems like climate change, and silence certain voices in doing so. Readers will be left with a reminder of the importance of the teacher as a critical curriculum maker – and needing to update their own versions of geography to do so.

    Many congratulations also to Darragh Woods  (MSc Learning and Teaching, University of Oxford) for the Highly Commended dissertation for a thesis titled: Artificial Intelligence (AI): How can we use Artificial Intelligence in Secondary School Geography?

    Darragh’s research into the use of AI in Geography teaching is timely and much needed. The focus on AI and creativity in teaching and learning, is original and interesting. Scholarship is exceptional, drawing from literature in psychology and AI, as well as geography education to problematise the teacher’s and the learner’s relationship to AI. Methodologically, the research is rigorous and carefully thought through. The dissertation provokes much reflection for teachers, ultimately raising more questions than answers. Darragh’s research invites teachers to think about what it means to be creative in teaching and learning the subject, and to challenge pre-conceptions about AI – be they negative or positive. The reader is left with the notion that AI can be a collaborative partner, potentially enabling creative geography teaching…in the hands of a critical teacher.

    Look out for further information on both research projects, including through blog posts on the GEReCo site.

    The 2026 GEReCo Masters Dissertation Award will open for submissions soon at https://www.gereco.org/about/gereco-masters-dissertation-award/

  • What’s up with the weather?

    Watch this Geography Education Research Collective (GEReCo) open seminar to hear an introduction to attribution science, a discussion of the latest research in the field, and to explore the challenges facing teachers in addressing questions about the relationships between weather events and climate.

    Find out more about Dr Nicholas Leach’s work here: https://www.physics.ox.ac.uk/our-people/leach

  • What’s up with the weather? Attribution science for teachers of geography

    GEReCo Open Seminar, March 19th 4:30-5:30pm, Online

    Dr Nicholas Leach, University of Oxford

    Sign up here: https://forms.office.com/e/BPFLN8BMqq

    Join this Geography Education Research Collective (GEReCo) open seminar to hear an introduction to attribution science, a discussion of the latest research in the field, and to explore the challenges facing teachers in addressing questions about the relationships between weather events and climate. Find out more about Dr Nicholas Leach’s work here: https://www.physics.ox.ac.uk/our-people/leach

    Photo by Carl Jorgensen on Unsplash

  • We are all Gravesian

    Professor John Morgan

    On Thursday this week (30.01.25), I received two messages. The first was to announce the publication of the Handbook of Geography Education, edited by Sarah Bednarz and Jerry Mitchell. The second was a reminder that Norman Graves was celebrating his 100th birthday. It was a fitting coincidence because Norman Graves was one of the founders of the field of geography education research during his tenure at the University of London Institute of Education (now UCL). Although there are few direct references to Graves’s work (about a dozen), the Handbook reflects the work he did to define the problem-space of the field.

    Elsewhere, I have often remarked that the making of modern geography education at least in the UK can be dated to the publication of three founding texts. These are Graves’s (1975) Geography education, David Hall’s (1976) Geography and the geography teacher, and Bill Marsden’s (1976) Evaluating the geography curriculum. Published around the same time, what they had in common is that they were attempting to make sense for teachers of the convergence of curriculum theory and geographical theory. Geography was going undergoing its conceptual revolution and education was being reshaped by new findings from educational psychology and the introduction of rational curriculum planning. Graves summarised the challenges for geography teachers, who must make sense of the philosophical basis of their teaching and consider psychological questions of how young people learn. He noted that there were sociological questions of why some children learned faster and more effectively, but this was not his prime concern (even though it was of growing interest to others and spawned the birth of the ‘new sociology of education’ (Young 1971) also at the Institute of Education (IoE).

    Graves offered a pragmatic solution to the question of the overarching conceptual framework or ‘paradigm’ with which to work. He suggested there were three such paradigms vying for attention in geography in the 1970s. These were the spatial organisation paradigm, ecosystem paradigm, and critical social science. He stated his preference for the ecosystem paradigm as most effectively allowing teachers to make the transition from the old regional paradigm to the new geography in school. He was unclear about the value that critical social science or radical geography might have for the subject in schools.

    In passing we should note that Graves advocated and set the standard for using educational research as the basis for rational curriculum planning. In this he was very much a product of the time. Graves joined the IoE in the mid-1960s the time of the expansion of teacher training and educational research. He introduced the landmark MA in Geography Education in 1978. Dennis Lawton had been appointed as the first Professor of Curriculum Studies in 1964, and Harold Rosen and James Britton led the English section. They set about modernizing the training of teachers in the face of comprehensive schooling and curriculum change. Graves’s 1975 book Geography education was based on these courses. This was the first shift towards curriculum theory in geography education and his follow up – Curriculum Planning in Geography (1979) – defined the curriculum problem for teachers and offered practical advice on how to solve it.

    Graves, like all of us, was shaped by the politics of the time. He took up his role at the IoE at the height of the progressive educational settlement, a time of optimism about the prospects for improving learning for all, and teachers and teacher educators enjoyed relative autonomy.  The frontiers of knowledge about the organization of learning were expanding, and universities were trusted as the best place to codify and pass on this knowledge. Those who worked with Graves took on and developed many of the ideas (Ashley Kent, Eleanor Rawling, Mick Naish, Frances Slater and a little later, David Lambert). By the late 1970s this consensus was beginning to breakdown and education policy took on a harder edge. Graves wrote increasingly about the need to defend teacher education (this is part of a longer story for another time).

    For now, I simply want to acknowledge that what we recognise as the field of geography education research owes much to Norman Graves who effectively defined the problems of the field. Things have moved on, of course, and by the 1990s teacher education was increasingly defined by technocratic approaches and the critical turns in academic geography posed new challenges for curriculum theory in geography education. The internationalization of the field, something Graves encouraged and was part of, has brought with it new ways of writing and thinking about geography education, as reflected in Bednarz and Mitchell’s impressive Handbook of Geography Education.

    The publication of this major contribution to geography education research on the centenary of one of its founders reminds us that we have always been, and remain, Gravesian in some way, whether this is explicitly acknowledged or not.

    References

    Bednarz, S. and Mitchell, J. (2025). Handbook of geography education. Springer.  https://link.springer.com/referencework/10.1007/978-3-031-72366-7

    Graves, N.J. (1975). Geography in Education. London: Heinemann  Educational Books.

    Graves, N. J. (1979). Curriculum planning in geography. London: Heinemann  Educational Books.

    Hall, D. (1976). Geography and the geography teacher. Unwin Education Books.

    Marsden, W.E. (1976) Evaluating the geography curriculum. London: Oliver and Boyd.

    Young, M. F. D. (1971) (Ed) Knowledge and Control: new directions for the sociology of education. London: Collier-Macmillan

  • New Progress Reports on Geographical Education

    Steve Puttick

    Following progress reports in Progress in Human Geography on geographical education by Rex Walford in the 1970s, Norman Graves in the 1980s, and Christine Winter in the 2010s, the most recent set of progress reports on geographical education have just been published:

    Geographical education I: fields, interactions and relationships

    Geographical education II: anti-racist, decolonial futures

    Geographical education III: changing climate, changing geographies, changing geographical education?

    Together, they aim to offer a critical account of the field by reviewing some of the major developments, examining trends reflecting on the changes in priorities for the research and practice of geographical education. The first report sketches the areas and sub-disciplines involved with geographical education and highlights opportunities for its contribution to public reasoning. The second examines trends around decolonial approaches towards geographical education and argues for the importance of anti-racism. The third and final report focuses on climate change, charting the rapid increase in attention to the issue and critically reviewing the multiple ways in which geographical education is grappling with this complex and urgent challenge. I hope the reports are useful for a wide range of colleagues working in the many different areas that together construct geographical education, ultimately contributing to the question that concludes the third report: How might we build geographical education that is creative, robust, generous, hopeful and diverse enough to empower and inspire everyone teaching and learning geography to create more just and equitable futures amid a changing climate?  

    Geographical education I: fields, interactions and relationships

    Abstract

    Complex global challenges, rapid shifts in the mediation and distribution of information, rising inequalities and a toxic milieu of low-quality public reasoning make geography education more important than ever. This first progress report explores the nexus of geography education research, geography education practice and scholarship and the geographies of education. Conceptualising the fields through expansive understandings positions this report in an optimistic space, highlighting significant opportunities for geography and its contribution to public reasoning through deepening collaborations and attending to tensions in education’s ‘shadow and shine’: tensions between its complicity in maintaining unjust hierarchies against its potential for emancipatory transformation.

    Link: Geographical education I: fields, interactions and relationships – Steven Puttick, 2022

    Geographical education II: Anti-racist, decolonial futures

    Abstract

    This report critically reviews developments in geographical education through the themes of anti-racism and decoloniality, reflecting on the silences around these issues across previous progress reports and arguing that the present moment might be understood in terms of a decolonial turn. Publication trends and increasing attention associated with the turn are unevenly distributed, contested and attenuated by structural issues surrounding the recruitment and retention of more diverse geographers. The report concludes with suggestions for developing anti-racist, decolonial futures through improving representation, addressing disciplinary fragility, and giving greater attention to nuance and singularity.

    Link: Geographical education II: Anti-racist, decolonial futures – Steve Puttick, 2023

    Geographical education III: Changing climate, changing geographies, changing geographical education?

    Abstract

    This third progress report critically examines the shifting role of climate change in geographical education: from a peripheral concern to an urgent and defining priority. Climate change now occupies substantial space across research, practice and curriculum, however, this transformation unfolds amid ongoing ‘lag’ between public discourse, research evidence, and curriculum development. Highlighting tensions across urgency and complexity, global and local scales, and representation and justice, the report concludes with a call for building geographical education futures that are creative, generous, hopeful, diverse and robust enough to meet the challenges of climate change.

    Geographical education III: Changing climate, changing geographies, changing geographical education? – Steve Puttick, 2025

    If you don’t have access to that version, the Accepted manuscript is freely available in Oxford University’s Research Archive here: Geographical education III: changing climate, changing geographies, changing geographical education? – ORA – Oxford University Research Archive

  • The potential of knowledge-rich teaching

    David Lambert

    This brief memorandum provides a succinct summary of Future 3. It draws from a longer open access article published mainly for a German audience of geography educators: https://zgd-journal.de/index.php/zgd/issue/view/167 which provides more detail and importantly citations and references – these ideas do not just rise without trace. The International Geographical Union Commission for Geographical Education (IGU-CGE) is holding a panel discission to explore international perspectives on Future Three scenarios (August 25th 2024) which will focus on key emergent questions such as,

     1. What changes in teacher education and professional development are needed for teachers to enact a progressive knowledge-rich geography curriculum?

    2. How might these changes be implemented in the context of national policy for schools and the geography curriculum?

    3. How might these changes be sustained so that they are transformative?

    Hard Times, published 170 years ago, was Dickens’ satirical destruction of education based upon ‘nothing but facts’. It remains an eloquent revelation of capitalism’s power to reduce humanity to numbers and definitions. In educational terms this meant reducing learning to fact and reifying a pseudo-scientific ‘reasoning’ process that purported to be value-free, objective, and devoid of feeling, emotion, and intuition. Today, when many schools proclaim their curriculum as knowledge-led and/or knowledge rich, to what extent have we learned some of the lessons provoked by the narrow and harmful processes of education depicted in Hard Times? If there remains a shadow of Thomas Gradgrind then it is not for want of repeated attempts to move on from ‘nothing but facts.’ For instance, over 50 years ago Postman and Weingartner famously called for anew education‘to help all students develop built-in, shockproof crap detectors.’ The old education, they argued, was predicated on absolute, fixed and unchanging ‘truths’ and did not encourage critique. It was dominated by certainties, often binary rights and wrongs and did not encourage ambiguity.

    The new education emphasised learning more than teaching, focussing teachers’ attention not on teachable knowledge but on the learner. Gert Biesta has called this the ‘learnification’ of education, and while this may produce competent, socially skilful, and highly flexible human capital, it risks turning out young people who are in some ways significantly untaught. The ‘swing’ between old and new education, between traditionalist and progressive educational thought, between modernisers and conservatives, continues. With a potentially epochal election having now taken place we should ponder this carefully.

    It is possible to imagine a third option, which is exactly what Michael Young and Johan Muller attempted to do in their 2010 paper on three future curriculum scenarios. These are caricatures, but they contain enough veracity to facilitate meaningful and productive debate about the curriculum:

    Future 1 (F1) is a curriculum consisting of ‘given’ knowledge that is seemingly uncontested. The teacher delivers these authorised contents. It is a traditional curriculum of one-way transmission.

    Future 2 (F2) is a response to the deficiencies of a transmission model of the curriculum Subject boundaries are relaxed or even dissolved. Content becomes increasingly arbitrary, and instead generic and transferrable skills are brought to the forefront.

    Future 3 (F3) restores the responsibilities of teachers for ensuring pupils have access to knowledge (they are more than ‘facilitators of learning’). But unlike F1, knowledge is contested, dynamic and subject to argument. Students are encouraged to discern the reliability or dependability of knowledge claims. This is a curriculum of engagement with knowledge itself.

    F3 curriculum scenarios address the inadequacies of both F1 and F2. Thus, under F3 it is accepted that all knowledge is socially constructed – it is produced by groups of human beings – but this does not mean that all knowledge has equal claim to truth, rendering selections of what to teach arbitrary. F3 recognises the virtuous educational intent that can be present in both the ‘traditional’ F1 and the ‘progressive’ F2 scenarios. Thus, in F3 scenarios specialist disciplinary knowledge (sometimes referred to as ‘powerful knowledge’) is a curriculum principle, but the focus of attention is on how this knowledge is made (and by whom), how it gains (or loses) its warrant, and how it changes over time. Curriculum knowledge is not the same as the knowledge it draws on. In short, F3 thinking resolutely rejects the ‘old education’ but imagines the ‘new education’ focussed on teachers’ work and the quality of the enacted curriculum.

    F3 curricula:

    • ask ‘who are we teaching?’ This is to acknowledge and respect students’ lived experiences, aspirations, and drives as learners;
    • are mindful of the prime reason that schooling is compulsory – that there is important knowledge that students can acquire at school that is beyond their everyday experience, and that acquiring it is necessarily a voluntary action on the part of the learner;
    • recognise that there are different ways of ‘knowing’ the world. For example, although we learn much through our everyday experience, this is very different from learning to see the world as an object of study and it is this difference that pupils can pose the greatest difficulties for some students;
    • provide opportunities and encourages students to think about how we know what we claim to know;
    • seek to show the ‘power’ of different ways of seeing and thinking associated with different subjects.

    F3 thinking encourages a shift from the technical competence and efficiency of teachers to implement and deliver content, towards the kind of dialogue and conversation with and among students that demonstrates their engagement and encourages the search for new knowledge. Claims for curricula based on ‘powerful knowledge’ are easy to assert. However, if through their implementation such curricula achieve little more than short-term memorisation, then much of the emancipatory potential of knowledge-rich teaching is lost. This point is arguably of greatest significance for students of minoritised and/or socio-economically disadvantaged backgrounds.

    A yet more ambitious claim is that a F3 curriculum might even begin to address how school curricula – and teaching itself – can face up to epochal challenges such as the rise of post-truth politics, conspiracy theories, the yet to be understood educational implications of artificial intelligence and the environmental and political crises that the climate emergency points to.

    Reference

    Lambert, D., Béneker, T. and Bladh, G. (2024) Teaching Quality in Geography: what are we trying to achieve? Zeitschrift für Geographiedidaktik, 51, 3, 156-159. DOI: 10.60511/51187

    https://zgd-journal.de/index.php/zgd/article/view/187/482