Students in science and engineering (S&E) are preparing for careers in fields where international partnerships are increasingly important to advancing knowledge and discoveries. It has been over a decade since the National Science Board (NSB) highlighted the importance of international collaboration and called for increased government commitment to promoting international S&E research and education. The National Science Foundation (NSF) contracted with Abt Associates to conduct an evaluation of the East Asia and Pacific Summer Institutes (EAPSI) program to investigate whether it was meeting its goal of providing U.S. graduate students with international experiences that will enable future collaboration with foreign peers. This report presents the findings from this evaluation. The evaluation found evidence that the EAPSI program is meeting its goals to: (1) introduce U.S. graduate students to East Asia and Pacific science and engineering in the context of a research setting; and (2) help students initiate scientific relationships that will better enable future collaboration with foreign counterparts. The following are appended: (1) NSF-Generated EAPSI Descriptions; (2) Non-Response Bias Study; (3) Detailed Description of Impact Analysis; (4) Detailed Description of Benchmarking Analysis; (5) Surveys; and (6) Benchmark of Applicants to National Data.