Answer: Many informant characteristics may be associated with scores on all kinds of questionnaires. Because any reports by any informants may be affected by characteristics of the informants, as well as by their own particular knowledge of the older adult’s functioning, no single informant’s reports can provide a complete picture. It is desirable to construct a comprehensive picture of the older adult’s functioning from multiple sources and types of data. The answers to questions in the section of this chapter dealing with profiles address lie scales and provide guidelines for evaluating problem scores that are so low or high as to suggest gross distortions or errors. Chapter 8 of this Manual provides data on reliability and cross informant agreement, while the Ages 60-90+ Module for computer scoring displays comparisons and correlations between informants’ reports for a particular older adult.