The original 36-item survey of perceived organizational support (SPOS) was evaluated to determine the underlying structure of the instrument. The survey items were subjected to a principal axis factor analysis. Reliability analyses for shorter versions of the SPOS were also conducted as a means to compare the internal consistency across forms (36-items, 16-items, 8-items, and 3-items). Finally, to evaluate the validity of the total scores for the different versions of SPOS, total scores from the three versions were regressed on three measures commonly included in studies that also use the SPOS: affective commitment, organizational participation, and organizational communication. Results indicate that the 36-item survey of perceived organizational support is unidimensional. The three versions that contain a reduced number of POS items are also unidimensional. All four versions of the SPOS are comparable in terms of internal consistency reliability. Likewise, all four versions performed equally in terms of thSchool of Teaching and Curriculum Leadershi
