Logically, an attempt should be made to define what is meant by subjective measurement methods, but there is an even more fundamental question: Why be interested in subjective measurement? Considering what HF professionals have been taught about the deficiencies of subjective data (the reliance on unreliable memory, the subject’s unconscious biases, the subject’s difficulty in assessing his/her internal condition), and the preferred status of objective methods (supposedly untainted by human agency), why bother about subjective data?