This study examines two topics:(1) to test hypotheses derived from the model regarding the effects of small group participation upon organizational commitment and job satisfaction, and (2) to compare these effects between Japanese and the U.S. workers. Data from a survey of over 4000 workers in nearly 100 plants in Japan and the U.S. were used to examine validity of the model. Results indicated that among Japanese workers small group experiences produced the effects predicted by the model: small group activities increased the opportunities for participation and the degree of interaction among group members, and the challenge and meaningfulness of the job. Then, these changes in work environment enhanced organizational commitment and job satisfaction of participants. However, the model was not fully supported on the U.S. sample: while small group participation had similar positive effects on commitment and satisfaction, they do not lead to significant changes in job contents and interaction among members. Implications of differential small group experiences were discussed.