Retaining nearly one-third more majors with a trio of instructional best practices in CS1

Beginning in 2008, we introduced a new CS1 incorporating a trio of best practices intended to improve the quality of the course, appeal to a broader student body, and, hopefully, improve retention in the major. This trio included Media Computation, Pair Programming, and Peer Instruction. After 3 and 1/2 years (8 CS1 classes, 3 different instructors, and 1011 students passing the course) we find that 89% of the majors who pass the course are still studying computing one year later. This is an improvement of 18% over our average retention of 71% for the previous version of the course (measured since Fall 2001). If the focus shifts from retention of passing CS1 majors to retention of CS1 initially enrolled majors, multiple improvements--fewer students drop, more students pass, and more passing students are retained--compound to increase retention by 31% (from 51% to 82%). In this paper we analyze further aspects of these results, detail the three instructional design choices, and consider how they impact issues known to affect retention.