This chapter summarizes the need for fuzzy measurement in many fields of psychology. The chapter also describes a fuzzy graphic rating scale, its validation, and ways in which the scale can be used in various fields. Fuzzy logic defines concepts and techniques which provide a mathematical method able to deal with thought processes which are too imprecise to be dealt with by classical mathematical techniques. A perennial issue in psychological assessment has been the extent to which differences in psychological test scores are a function of genuine individual differences rather than differences imposed (or obscured) by the constraints of the measurement procedures. Fuzzy set theory takes account of the reality of imprecision of human thought by allowing ranges of scores to be measured and translated into a single score. Sherif and Sherif discussed the notion of latitudes of acceptance and rejection in attitude measurement. The fuzzy graphic rating scale offers a direct way of addressing these notions of ranges within the domain of attitude measurement.