ExTeX — Interactive Lecture Notes and Exercises with Automatic Feedback in TeX
In technical fields, we write our documents almost exclusively in TeX/LaTeX. The goal of this project is to provide the means of integrating interactive elements (such as multiple choice questions with automatic feedback, but also more advanced and complex features) in TeX-documents using native syntax already familiar to instructors, and resulting in a look and feel already familiar to students.
The project
This project was about creating software tools that allow instructors to create TeX documents for teaching purposes that contain interactive components. These interactive components allow students to give answers to clarifying questions and exercises, which are then immediately graded and dynamic feedback depending on the student’s answer is given.
The motivation for this project came from the following observation. Most documents (be it for teaching or research purposes) in our field (that is, theoretical computer science, but of course also related fields like mathematics) are written in TeX/LaTeX. This is done so for good reasons and without any real alternatives. However, as the nowadays usual output format of TeX is a static PDF (which is then typically sent to a printer), there is no native support for interactive components as described in the first paragraph. The goal of this project was to close precisely this gap. That is, we wanted to make it possible to have for example interactive lecture notes in HTML format with automatically graded exercises that are compiled from source files written exclusively in TeX/LaTeX.
Implementation into teaching practice
So far, we have made use of the developed tools in two particular courses. However, note that the generic nature of the project makes it suitable for potential use in a large number of other courses as well.
For one, we have added interactive components to an old LaTeX document that has seen constant use for over a decade in the course «Algorithms, Probability, and Computing». The document serves as a refresher for students about some basic concepts from probability theory that they are expected to know before taking this course. We believe that the interactive nature of the new document (with many clarifying questions and the possibility to receive immediate feedback) improves the learning experience greatly.
On the other hand, a set of 7 reading assignments with interactive exercises was prepared in ExTeX by B. Gärtner, tailored for students in the CAS Applied Information Technology, with the goal of bringing their math background up to scratch. Feedback from students was extremely positive. During preparation of the assignments, the IDE allowed for a seamless and enjoyable process. Due to only a relevant subset of LaTeX being supported by ExTeX, compiling documents is much faster than with pdflatex, say, increasing the efficiency of the edit-compile-view cycle.
Lessons learned and further impacts
During this project’s duration, an existing prototype of this tool was extended and developed further. Some of the most notable additions are the following:
1. The existing primitive TeX-Compiler (which is used to generate the required HTML output files) was extended to support a variety of previously missing fundamental TeX features. This includes for example full support for category codes, full macro expansions, and reading and writing from and to the file system.
2. A more user-friendly web IDE for creating documents was developed. In particular, it allows all the required project files to reside on the author’s hard drive, which makes it possible to edit the TeX sources with local tools and editors.
3. More interactive components were added, such as the possibility to give answers as arbitrary strings, which are then evaluated based on whether they match some given regular expressions. Moreover, a much more expressive way of declaring automatic feedback was invented.
4. An export functionality was added that allows to create a standalone HTML file for any given document, which includes all the necessary fonts, figures, code, and so on. In principle, this allows for easy distribution of the resulting documents, which are not dependent on the online platform and which can be worked on by students with all interactive features even without an internet connection.
5. A large number of previously missing high-level LaTeX features are now supported. This includes things like TikZ figures, tables, table of contents, references, and much more.
The impact of the project on student learning is difficult to measure. However, we believe that the interactive nature of the resulting documents enhances the learning experience for many students. We hope to receive more concrete feedback from the students in the evaluations of the two courses where the tool was used.
The generic and automated nature of the developed tools make an adaptation to other courses and to larger student populations straight forward.