Jacoby, W. G. (1991). Data theory and dimensional analysis (Sage University Paper Series on Quantitative Applications

The item is the basic unit of a psychological scale. It is a statement or question in clear, unequivocal terms about the measured characteristics (Haladyna, 1994). In social science, scales are used to assess people’s social characteristics, such as attitudes, personalities, opinions, emotional states, personal needs, and description of their living environment. An item is a “mini ” measure that has a molecular score (Thorndike, 1967). When used in social science, multi-item measures can be superior to a single, straightforward question. There are two reasons. First, the reliability of a multi-item measure is higher than a single question. With a single question, people are less likely to give consistent answers over time. Many things can influence people’s response (e.g.