There has been longstanding interest in affective characteristics in both educational and corporate environments. While each domain has produced its own set of theorists and researchers, the work of some, such as Bandura, has found a place in the literature of both areas. In each of these settings, theorists and researchers have agreed on the causal connections between such constructs as self-efficacy and perceived satisfaction and success, whether that success is measured by academic achievement or corporate quality and performance resulting in profitability. Along with this interest, comes the need for the development of valid and reliable instruments to assess affective characteristics. It is clear that no matter whether your interest lies in the relationship between self-efficacy and academic success or employee satisfaction and corporate success, it is essential that the instruments used be carefully designed and tested to assure that they are measuring what they are intended to measure in a consistent manner. This work offers the theoretical perspective, modern psychometric techniques, real examples, and data needed to enable the instrument developer to produce such valid and reliable instruments.