A summer bridge program for incoming engineering and computer science freshmen has been used at the University of Wisconsin-Milwaukee from 2007 to 2010. The primary purpose of this program has been to improve the mathematics course placement for incoming students who initially place into a course below Calculus I on the math placement examination. The students retake the university's math placement examination after completing the bridge program to determine if they then place into a higher-level mathematics course. If the students improve their math placement, the program is considered successful for that student. The math portion of the bridge program is designed around using the ALEKS software package for targeted, self-guided learning. In the 2007 and 2008 versions of the program, both an on-line version and an on-campus version with additional instruction were offered. In 2009 and 2010, the program was exclusively in an on-campus format, and also featured a required residential component and additional engineering activities for the students. From the results of these four programs, we are able to evaluate the success of the program in its different formats. In addition, data has been collected and analysed regarding the impact of other factors on the program's success. The factors include student preparation before the beginning of the program (as measured by math ACT scores) and the amount of time the student spent working on the material during the program. Better math preparation and the amount of time spent on the program were found to be good indicators of success. Furthermore, the on-campus version of the program is more effective than the on-line version. (Contains 6 tables and 1 figure.)