Boolean evaluator to grade chemistry answers

Updated 30 Aug 2024

Use the Boolean answer evaluator to check two or more conditions using “and” or “or”.

For skeletal answers, select expressionBoolean.
For mechanism answers, select expressionBooleanMechanism.

Select Grade as Correct or Grade as Incorrect, then enter the conditions you want to be checked in student answers.

How “And” and “Or” work in the Boolean answer evaluator

And — ALL of the answer evaluators within the Boolean must match for the whole Boolean evaluator to match.
Or — If any of the answer evaluators match, the whole Boolean expression matches.

Add the answer evaluators you want to combine

After you choose the Boolean operator, add the answer evaluators you want to combine for student answer evaluation.

Select Add Evaluator, choose an evaluator from the provided list, and enter the conditions for the answer evaluator.
Select Add Evaluator again to add a second and any subsequent evaluators.

When multiple structures are needed for the correct answer

Use the Boolean answer evaluator to evaluate multiple structures in a correct answer.

Code each structure using the Is evaluator (expressionOchemEvalIs).
Include the Number of Molecules evaluator (expressionOchemEvalNumMols) to ensure that the total number of structures does not exceed that required for the correct answer. For example, a correct answer could be both the ortho and para products of a bromination of a benzene ring.

Add a wrong answer response (optional)

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.