Abstract
Online-based assignment collections for STEM subjects contain symbolic, arithmetic and answer-choice questions with automated feedback. The open-source plugin STACK (System for Teaching and Assessment using a Computer Algebra Kernel) can be used for this purpose, which allows the creation of randomized tasks based on a computer algebra system. The creation of valid tasks in STEM subjects is very time-consuming and therefore error-prone. An exchange of created assignment collections as OER material would be ideal in this purpose.
By using STACK tasks, learners can be offered individual feedback and learning paths. In order to be able to use assignment collections from different sources in a course, standardization of solution input, the structure of learning paths and the given feedback is required to provide learners with a consistent user experience.
As a solution, the use of a style guide for the creation of STACK tasks is suggested to facilitate the exchange and use of tasks between universities and disciplines. Requirements for a consistent presentation of tasks and the design of learning paths are provided based on best-practice examples.
The style guide addresses, among other things, the following questions:
• How do I structure a task/feedback?
• What settings should I choose?
• How can variables be used meaningfully?
• How can images be integrated into tasks?
• How can formula symbols and units be parameterized to allow adaptation to different disciplines or countries? For example, in electrical engineering, the complex number "i" is denoted by the symbol "j".
The style guide contains a handout with instructions for use for learners, which can be integrated into the tasks. In addition, the style guide shows how tasks can be automatically converted according to your own requirements (e.g. converting formula symbols or units).
The advantages of a style guide would be:
• The style guide serves as an orientation aid when creating STACK tasks and thus helps to avoid errors when creating tasks.
• The possibility of interdisciplinary and international exchangeability of STACK assignment collections.
• Learners receive a standardized presentation of tasks and feedback, which contributes to orientation and ease of use.