Kuleshov used the experiment to indicate the usefulness and effectiveness of film editing. It retains validity, usefulness and reliability between raters. Intrinsic motivation positively predicted perceived ease of use, usefulness, and actual use. They were of doubtful reliability, usefulness and efficiency. Community environment positively predicted perceived ease of use and usefulness. House criticizes social etiquette for lack of rational purpose and usefulness. Further anecdotal observation convinced Lotsof of its potential usefulness in treating substance addictions. This he saw as having an everyday importance, a usefulness for living well. Catholics are exhorted to beware of underrating the usefulness or necessity of vocal prayer. The ELM has been studied with regard to its usefulness in politics and voting specifically. Energy conversion efficiency depends on the usefulness of the output. There is considerable debate about the usefulness of the MVP. The subject has produced much debate about rankings' usefulness and accuracy. There is much debate about rankings' interpretation, accuracy, and usefulness. The usefulness of the concept is disputed.