The Contains expression

The Contains expression (expressionOchemEvalContains) checks whether a student’s response includes a molecule fragment or substructure of an authored molecule. This evaluator will NOT work for entire molecules.

The Contains expression is available for items you create with either the solutionOchemSkeletal or solutionOchemMechanism answer type.
How to add one or more expressions
How to specify the Grade and Response information
Use the dropdown menus and text boxes to set or edit the molecular fragment you want to be evaluated in student responses.
For best results, include only one or two substructures per evaluator. Adding too many substructures negates the benefit of the Contains evaluator. For full structures, use the Is expression.

"If" options

Menu Option	Description
No compound in the response	None of the molecules in the student’s response matches the authored fragment.
The only compound in the response	The student’s response includes one and only one molecule which matches the authored fragment.
Exactly one compound in the response	The student’s response includes one compound (not more) which matches the authored fragment. The student’s response may contain other molecules of different types which do not match the authored fragment.
Any compound in the response	Any of the molecules in the student’s response matches the authored fragment. The student’s response may contain more molecules which also match.
Not every compound in the response	Not all of the molecules in the student’s response match the authored fragment.
Every compound in the response	All of the molecules in the student’s response match the authored fragment.

"Contains" options

Menu Option	Description
Substructure	Any subset of contiguous atoms connected by bonds in the student’s response is compared to the authored molecule. Some of the connected atoms in the student’s response, not necessarily all of them, can match the authored molecule.
Skeleton	All of the contiguous atoms connected by bonds (complete molecule) in the student’s response are compared to the authored molecule.

“With charge, radical, isotope states” options

Menu Option	Description
Matching exactly	The student’s response is the same the author’s.
Ignored	The charge, radical, and isotope states of the student’s response may or may not match the author’s.
In author’s structure present in the response	Some part of the student’s response matches the author’s response.

Compound Label

Compound (add a molecule)

The Contains expression

See also: