Rings evaluator to grade chemistry answers

Updated 30 Aug 2024

Use the Rings evaluator (expressionOchemEvalRings) to compare the number of rings in a student’s answer to the expected number of rings. A ring is any set of contiguous atoms connected by bonds (including single, double or triple bonds and wedge bonds) in a closed loop or ring.

The Rings evaluator works with the skeletal answer type.

  1. Select Grade as Correct or Grade as Incorrect, then enter the conditions you want to be checked in student answers.
  2. Select either:
    • the response has
      Counts all of the rings in the student’s response.
    • the number of compounds in the response that have
      Counts each compound (any collection of atoms connected by bonds) in the student’s answer which has the number of rings in the evaluator answer.
  3. Select an “is” option.

    exactly
    Student answer number = the number in this box

    more than
    Student answer number > the number in this box

    fewer than
    Student answer number < the number in this box

    not exactly
    Student answer number <> the number in this box

    fewer than or equal to
    Student answer number ≤ the number in this box

    more than or equal to
    Student answer number ≥ the number in this box

  4. Enter the number of rings for the evaluator.

Select Show this response to enter wrong answer feedback for when the student’s answer matches a Grade as Incorrect condition.

Use your keyboard and options from the editing toolbar and menus. Wrong answer and follow-up text can include an image, link, and formatted text like bullets or TeX.

 

See also:

Answer evaluators list (for correct or incorrect answers) | How grading evaluators work | Properties for the Marvin JS drawing tool setup