How useful is each item in the Sport Spectator Identification Scale?: an item response theory analysis

The purpose of this study is to evaluate the psychometric properties of each item in the Sport Spectator Identification Scale (SSIS) (Wann and Branscombe, 1993) using the item response theory (IRT) and to provide evidence for modifications in the scale.

A total of 635 spectators of US professional sports responded to the seven-item SSIS on an eight-point semantic differential scale. The general partial credit model was fitted to the data.

The results revealed that four items (Items 1, 2, 3 and 5) provide a relatively high amount of information, whereas three items (Items 4, 6 and 7) provide a low amount of information, indicating different levels of measurement precision among the items. Furthermore, the results showed that some low-level response options were rarely selected by participants, indicating that it may not be necessary to include response options as many as eight within each item.

Unlike previous studies examining the psychometric properties of the SSIS as a whole, the present study provides information about the usefulness of each item of the SSIS in measuring individuals' team identification. Based on the findings, the authors identified some issues with the three problematic items, including the wording of the items and the link between the question and the target construct. The authors make several suggestions for researchers and practitioners in improving individual item quality and in making informed decisions when using the SSIS in the future.