What if informants say they don’t know enough about an older adult to rate certain items?

Answer: If an informant has known the older adult for at least 2 months, he/she should be encouraged to complete the OABCL, even if guessing is necessary. The user can point out to the informant that a rating of 0 does not require complete certainty about the absence of the characteristic to which the item refers, but only that the informant does not know that it is true of the older adult, i.e., the instructions state: 0 = Not True (as far as you know).