This paper discusses the sensitivity of instruments used to measure knowledge and attitudes toward older people. Existing standardized measurement instruments are reviewed, including a detailed examination of Palmore's Facts on Ageing Quiz (FAQ). A recent study conducted by the research team into the knowledge and attitudes of support workers (n=155) employed in care homes for older people, which utilized the FAQ is described. Despite ongoing attempts to address the challenge of measuring knowledge and attitudes toward older people, previous literature reviews and the results of the recent support workers study have revealed inadequacies, confusion, contradictions, and a need for further research into this area. Further development and refinement of measures remain a key challenge for researchers working in this field. Service users (in this case, older people) will need to be actively involved in this process. If the reliability, validity, sensitivity, and specificity of existing instruments cannot, however, be further tested and established, then new instruments may need to be developed.