The purposes of this study were (1) to determine achievement levels of External High School Diploma Program (EHSDP) graduates at Waukesha County (Wisconsin) Technical Institute on the General Educational Development Test (GED) or other standardized tests nationally normed on high school students, and (2) to measure the basic skills level of current EHSDP participants in reading, mathematics, and language. The tests which were selected to fulfill these objectives were the GED and the Test of Adult Basic Education (TABE). An analysis of test scores for the fifteen graduates who participated in the GED indicated standard scores higher than the minimum Wisconsin standards. The thirteen graduates who completed the entire GED test battery surpassed minimum state standards with total scores ranging from 242 to 318 and a mean score of 277.76. Seventeen candidates for graduation completed all sections of the TABE, with total scores ranging from a grade equivalent of 8.4 to 12.9 (the highest attainable score). Of this population, 82.3% scored at 10.0 and above. The highest scores were recorded in language-spelling and reading skills. Lowest scores were recorded in mathematics. The mathematics section of the GED also yielded the lowest scores. From these findings it was concluded that the EHSDP graduates who participated in testing performed adequately on the GED and the program participants who completed the TABE demonstrated basic skills performance at an acceptable level. It was further concluded that mathematics was the weakest area of performance on both tests and warrants additional emphasis in the External High School Diploma Program. (Author)