There are four levels of measurement: nominal, ordinal, interval, ratio. Whether a single item or a composite (index or scale), greater understanding of any measure often comes with an evaluation of four moments: mean, standard deviation, skewness, and kurtosis. The quality of a measure is judged using several criteria, the most important of which are reliability, validity, and generalizability. Communication researchers employ a wide range of multivariate analytical tools (principle components analysis, exploratory factor analysis, confirmatory factor analysis) to assess measurement. This entry provides a brief overview of these measurement-specific topics.
