Graph editor

From the student point of view, the primary feature of GraphChecker is its graph editor, which was designed carefully to be as intuitive as possible. The editor has two modes:

The editor provides support for undoing and redoing actions ( / ) and other quality of life features, such as directly editing the label when typing commences. Depending on the exercise settings, different features may be available in the editor. Only available features are shown in the editor, and the help function () adapts itself to include information about the available features only. Two different possible setups are displayed in the editors embedded below. Feel free to play around with them, to explore the possibilities.

The following editor lets you draw a directed graph, highlight a subset of edges, and color its vertices blue, red, or green.

The following editor lets you draw a Petri net, edit the labels of places and transitions, and set the number of tokens in each place. The teacher has already pre-filled the editor with a ‘template’ for the solution. These elements can still be moved around, but cannot be edited or deleted.


GraphChecker is able to grade the student's answer automatically, by running a series of checks on it. The teacher specifies which checks are appropriate for each question, and the rest of the grading process will be fully handled by GraphChecker.

Depending on the teacher's preferences, a Check button may be available below the editor. Using this button, students can directly check their answer. This indicates to the student whether the test passed, and if not, supplies tailored feedback. The feedback is determined automatically, but may be refined by the teacher. Depending on the setup, checks may be unlimited, or each check may cost a fixed penalty in the exercise grade. If a Check button is not made available, then the checks will be performed after the quiz has been submitted.