STACK: an assessment system for mathematics in Moodle quiz.
2020-11-28, 12:40–13:00, Room 1

This talk is about STACK [1] (qtype_stack), an optional plugin for the Moodle quiz specifically targeted at the needs of mathematics, science and related disciplines. STACK moves beyond multiple choice questions by expecting students type an answer in the form of an algebraic expression.

Computer algebra tools establish the objective properties, such as algebraic equivalence with the correct answer and generate feedback based on these properties. STACK also lets teachers randomly generate versions of questions, with connected multiple parts, and worked solutions which reflect the randomization. A variety of inputs options provide support for scientific units, line by line working and clearly separate "validity" from "correctness" [2,3].

STACK has been developed continuously for over twelve years, it is widely used internationally and with a growing commercial user base. There is a large and growing community of STACK users on over 800 registered sites, including the University of Edinburgh, Loughborough University and the UK Open University. At the UK Open University STACK is the second most used question type after Moodle's MCQ, with over one million question attempts per year. Numerous major projects are underpinned by STACK, and community initiatives such as ABACUS ( have been set up to help academic colleagues pool materials. STACK is in regular use in English, Finnish, Swedish, Japanese, German, Spanish and Portuguese.

This talk will illustrate the question type with examples taken from online assessments we used in undergraduate courses at the School of Mathematics (University of Edinburgh). These were part of a major project which managed to bring mathematical assessments in-house within the Moodle quiz systems, replacing externally provided materials in a variety of third party systems. Taking responsibility for our own assessments gives academic colleagues more control over their teaching and students a more consistent user experience [4,5].

2. C. J. Sangwin, Computer Aided Assessment of Mathematics. Oxford University Press, Oxford, UK, 2013.
3. C. J. Sangwin and I. Jones, “Asymmetry in student achievement on multiple choice and con-structed response items in reversible mathematics processes, “Educational Studies in Mathematics, vol. 94, pp. 205–222, 2017.
4. K. Zerva, “Developing STACK assessments in Edinburgh, 2017–2019”, proceedings 1st STACK conference (2019)
5. Developing online learning materials to support undergraduate education at the University of Edinburgh, C. Sangwin and K. Zerva, Mathematics Today, Vol.56 No.3, June 2020.

See also: Presentation

Facilitator in Technology Enhanced Mathematical Education, School of Mathematics, The University of Edinburgh.

I completed my undergraduate degree in Physics in 2006 at University of Ioannina, Greece and I received a PhD in Experimental Nuclear Physics in 2013 from the same University. After that, I worked as a Teaching Assistant at the School of Physics and Astronomy and at the School of Mathematics at the University of Edinburgh. Since 2017 I have been working as Facilitator in Technology Enhanced Mathematical Education at the School of Mathematics. My main role is to design and develop online assessments for the undergraduate courses using the online assessment system STACK.