The vast majority of scales involve some form of scoring process. The score of the participant would otherwise be underestimated, as some of the guesses to multiple-choice items will probably be correct. Likert scales are commonly used to measure personality, attitudes. The scores from psychological scales are normally correlated with other things – for example, scores on other psychological scales, some aspect of behaviour such as simple reaction time. There is one transparent acetate sheet for each scale. There is plenty of scope for errors to creep in when scoring tests manually using templates – typically because the acetate scoring sheet is not correctly placed over the paper answer sheet or because the person scoring the test makes an arithmetic slip. Ignoring missing data from a Likert scale is a very bad idea. Dropping anyone with missing data from the analysis is much more defensible, but much depends on how much data is missing and how long the scales are.