Presentation by Frank Luebeck (Lehrstul D for Mathematics, RWTH Aachen) at the JEM Symposium on “math tutoring: tools and feedback” in Heerlen, Netherlands.
Due to huge number of students, the university wanted to switch from classical exercises to online exercises, partially graded automatically (multiple choice and similar).
Requirements
- Exercises are specified in (standard) LaTeX; no additional (semantic) macros.
- Individual sheets to avoid copying of solutions!
- High quality display on the web; but they use images only, which reduces/ hampers the accessibility e.g. for visual impaired people or screen readers.
- …more requirements …
Implementation
- Existing Systems (WebAssign, WebCT, Moddle) has a lot of functionality they didn’t need, and fulfilled few of their requirements (in 2002)
- OKUSON is home-made and thus fullfills all requirements; programmed in python; GPL license; hobby project so no technical support; buildin webserver with on-the-fly validation of XHTML; basically a webpage with can be easily extended
- exercise sheets are in simply XML-based file formats (see exercise template for an example; points to either classical exercise sheets in LaTeX or to interactive exercises); exercises are created with an offline texteditor
- Used by all mathematical freshmen lectures at RWTH Aachen, several German Universities (Hamburg, Hannover, …), used in England and Irland; many users; few bug report and support questions
- Implementation was very easy, the most difficult part was the invention of exercises
Student features
- register for system
- Download exercise sheet in PDF; enter solutions into the XHTML. XHTML is created by generating images for each exercise snippets from the LaTeX and inserting these images in an XHTML form. Student can solve the exercise several time until the deadline.
- Submit solutions, see grading, register for exams
Further details:
- question type: Single choice, multiple choice, answer as text (numbers and text)
- grading: +1 point for correct answer, -1 point for wrong answer, 0 points for no answer
- Interactive questions with variants (alternative question texts) with concrete instances; these alternatives are used to generate individual exercise sheets (based on the student ID); problem: the degree of difficulty might vary among these alternatives (e.g. template)
- statistics: how many percent successfully solved a variant of an exercise sheet; on-the-fly visualization of the statistics …
- all data stored in text files (also user data and results); simply querying of this data and further UNIX computations (grep, sort, …)
Evaluation:
- Did these online question help to understand linear algebra?
- Students very much liked the online exercises, were more motivated. Online system was used to approve the students registration for the pre-diploma. Grades were equal to results in traditional exercises; good students remained good; poor students remained poor. Participation increased (number of students taking the qualification exams increased). No complaints during the change from traditional to online exercises. Feedback was given during the lectures.
Future work: System can be easily be integrated with e.g. GAP or other system for automatic verification and immediate feedback.