Existing Wording: One of their purpose is to define variables, observations, or questions, that include information about how to collect a variable's value--including information about data types, and guidance about the use of about answer lists and/or units of measure.

Proposed Wording: One of their purposes is to define variables, observations, or questions that include information about how to collect a variable's value--including information about data types and guidance about the use of answer lists and/or units of measure.

Comment:

multiple typos