This document is the third volume in a set of five Career Education Measurement Handbooks intended to help local education personnel in measurement and evaluation. Divided into seven major sections, this handbook is designed to provide practical guidelines for improving career education instruments developed at the local level. It is primarily intended for people who lack training in evaluation and measurement but are responsible for this type of work. A brief introduction providing a checklist for rating career education instruments precedes the first section, which includes guidelines for planning and designing career education instruments. Sections 2 and 3 present information on checking reliability and determining validity, respectively. Eliminating stereotypes is the topic of section 4. Section 5 presents guidelines for devising the format. Section 6 discusses readability, and section 7 provides guidelines for examining content validity and internal consistency reliability. (BM)