Screen shots

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Bad answer (syntax error)

Bad answer (wrong output)

Bad answer (runtime error)

Right answer

C Function (hidden test case shown to teacher)

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pylint-checked question: bad answer

Java Class: teacher view (showing hidden test case)

Use of the Precheck capability

Easy template-grader example: right answer

Easy template-grade example: partially-right answer

Custom grader: right answer

Custom grader: wrong answer

Custom grader: syntax error

Before clicking "Show differences"

After clicking "Show differences"

Question authoring: the trivial Python3 sqr function

The Graph UI in action

The Gap-filler UI in action

The scratchpad UI in action

(a) Before being opened by the student

(b) After being opened and used for a simple test