A scale for measuring the persuasive impact of qualitative and quantitative evaluation reports upon decision makers was developed. Accepted psychometric scale-development procedures were followed that rigorously tested a pool of items. Using two exploratory and two confirmatory samples, the current research developed a 28-item Likert-like scale to measure perceived attention, liking, comprehension, generating related cognition, learning how, attitude and decision making. The scale demonstrated high reliability and validity. The instrument can be used to help researchers and practitioners estimate the impact of their reports upon decision makers.