The Development of a Brief Working Alliance Inventory for Clients and Therapists Using Multilevel Factor Analysis and Item Response Theory in the United States and China

This study aimed to investigate the multilevel factor structure of the therapist and client versions of the 12-itemWorking Alliance Inventory–Short Revised (WAI; Hatcher&Gillaspy, 2006) in the United States and China, and to create a three-item brief version (WAI-B3) using multilevel factor analysis (M-FA) and multilevel item response theory (M-IRT).We gathered eight data sets from two samples each in United States and Chinawith a total of 21,623 sessions from376 therapists and 2,455 clients. M-FA resultswith the first four data sets (two American and two Chinese) suggested that the 12-itemWAI across therapist and client versions, and in bothUnited States andChina showed a dominant generalWAfactor with three specific subgroup factors corresponding to the Goal, Task, and Bond items.Wethen constructed a three-itemWAI-B3 by selecting items 11, 10, and 9 through M-IRT, as the best representative of Goal, Task, and Bond subscales, respectively, for both the therapist and client versions in United States and China.With the other four data sets (two American, two Chinese) to test theWAI-B3, we found adequate multilevel reliability, structural validity, and convergent validity with the original 12-itemWAI scores. Multilevel measurement invariance tests provided tentative and mixed support for the equivalence of WAI-B3 between the American and Chinese data sets and between therapist and client versions.