CS 0.5: A Better Approach to Introductory Computer Science for Majors Robert H. Sloan and Patrick Troy Dept. of Computer Science, University of Illinois at Chicago Chicago, IL, USA [email protected], [email protected] ABSTRACT an attrition rate from freshman to sophomore year of 40– There are often problems when students enter a course with 60%, although our sophomore to junior year attrition has widely different experience levels with key course topics. If been fairly low. the material is covered too slowly, those with greater expe- Today this attrition rate is especially troubling because CS rience get bored and lose interest. If the material is covered departments in the U.S. have experienced a very substantial too quickly, those with less experience get lost and feel in- decrease in the enrollment in the CS major (see, e.g., [3, competent. This problem with incoming students of our 21, 23, 24]). Thus many, perhaps most, CS departments Computer Science Major led us to create CS 0.5: an intro- currently have too few majors. ductory Computer Science course to target those CS majors The attrition rate for CS majors is much worse than the who have little or no background with programming. Our attrition rate for other majors that have similar require- goal is to provide these students with an engaging curricu- ments for freshman—except for freshman courses in the ma- lum and prepare them to keep pace in future courses with jor itself. Therefore, we believe the problem must be the those students who enter with a stronger background. introductory course sequence in CS. Indeed, international Following the lead of Mark Guzdial’s work on using media studies of programming performance [14], declining reten- computation for non-majors at Georgia Tech, we use media tion rates [8], and student failure rates as high as 50% [19] computation as the tool to provide this engaging curriculum. show that CS departments today are not successfully at- We report here on our experience to date using the CS 0.5 tracting a wide range of students to introductory CS courses, approach with a media computation course. nor fully engaging those students who do enroll. Furthermore, the introductory course sequence seems to be serving the needs of women even more poorly than the Categories and Subject Descriptors needs of men (who make up a heavy majority of CS majors). K.3.2 [Computers and Education]: Computer and Infor- The enrollment of women in introductory CS classes keeps mation Sciences Education falling, and retention rates for women are even worse than for men (see, e.g., [2, 12, 13]). Women reportedly tend to avoid CS (and IT in general) in part because they find CS General Terms courses “too boring” and “overly technical,” with little room Human factors for creative “tinkering” [1, 13]. At a session devoted to in- creasing the enrollment of women at a recent ACM SIGCSE conference, speakers reported that women CS majors were Keywords often surprised by how much “creativity” there was in later Computer science major, retention, CS 1, curriculum CS courses, since introductory courses did not highlight this aspect of CS [17]. Women CS majors, in contrast to men, are mostly interested in real applications of computing, and 1. INTRODUCTION: THE PROBLEM not simply computing for its own sake [1, 13]. There is a problem with the first two years of the com- Addressing the factors that cause women to avoid CS, puter science (CS) major: very high attrition. The annual may also increase the number of men—in particular, men attrition rate among freshman and sophomores majoring in who currently are not retained in the major. Stephen W. CS in the U.S. has been reported to average 19%, and at Director, Chair of the U.S. Engineering Dean’s council, has some schools to be 66% [4]. At our school, we have observed testified that, “Women in engineering programs are the ‘ca- naries in the coal mine’. If women do well in a program, most likely everyone else will also do well.” [6]. An additional problem is severe underrepresentation of Permission to make digital or hard copies of all or part of this work for African Americans and Hispanics among CS majors. This personal or classroom use is granted without fee provided that copies are problem has been less studied than the shortage of women, not made or distributed for profit or commercial advantage and that copies perhaps because at many schools there are so few CS majors bear this notice and the full citation on the first page. To copy otherwise, to from these groups that it is difficult to make any statistically republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. meaningful statements about their numbers. SIGCSE'08, March 12–15, 2008, Portland, Oregon, USA. Copyright 2008 ACM 978-1-59593-947-0/08/0003 ...$5.00. 2. PROPOSED SOLUTION: OVERVIEW on data structures, but not quite large enough for a stan- We hypothesize that providing two, rather than one, start- dard three-course sequence (despite concerted efforts in this ing points for the CS major will significantly improve the direction [18]). retention of CS majors in general, and women in particular. Starting the CS 1 course with students who all have a basic Thus, rather than there being a single “CS 1” that is taken knowledge of programming can provide a robust solution to as the first course in the CS major by every major, there this dilemma. would be two courses: “CS 0.5” and “CS 1”. 2.2 Media Computation as CS 0.5 Briefly, the idea of CS 0.5 is that most incoming majors will take CS 0.5; a substantial minority (perhaps 20–30%) Having decided that one should have a CS 0.5 that comes will go directly into a mildly aggressive version of a tradi- before a mildly aggressive traditional CS 1, one next has tional CS 1 course. The objectives of CS 0.5 are to give to decide what to teach in CS 0.5. As we said above, we students a moderate amount of what we might call “pro- want to provide our students with some “programming ma- gramming maturity,”by way of analogy with what our math- turity,” and we want to engage and excite our students with ematician colleagues refer to as mathematical maturity, and computer science. to instill both enthusiasm for, and general knowledge about We chose to adapt the Python version of Guzdial’s In- computer science (which is of course not at all the same troduction to Media Computing course, which was devel- thing as programming). At our school, University of Illinois oped for use as a non-major’s introduction to CS at Geor- at Chicago (UIC), the typical incoming CS major has rel- gia Institute of Technology (“Georgia Tech”), as our CS 0.5 atively little (and occasionally no) background in program- course. That course has students writing Python programs ming; but a substantial minority have moderate or substan- to manipulate images (e.g., creating Photo-shop style fil- tial background in programming. ters), sounds, animations, and text. In Section 2.1 we describe why we think this CS 0.5 ap- We felt that most of Guzdial’s argument’s about why that proach is a good idea, and then in Section 2.2 describe why course was good for Georgia Tech’s non-CS-majors were also we chose to use a lightly modified version of Guzdial’s Me- good arguments for using it for CS 0.5. In particular, we dia Computation course for non-CS-majors [7, 9, 10] as our think the multimedia approach is a good one because most CS 0.5. students enjoy multimedia already and are thus likely to be very interested in manipulating images, animations, and 2.1 WhyCS0.5? music themselves. We also like the Georgia Tech approach that allows one to first work with the multi-media material First, let us point out that it is common to have many itself, then with programming shortly thereafter. entry points for college-level study of established technical Python is also a good choice of language, because it is disciplines. At our school there are several “first” courses in not too close to Java, the language used in the rest of the each of Mathematics, Physics, and Chemistry. In all three sequence. We want to make sure that CS 0.5 is providing of those cases there are at least two courses that are fairly only programming maturity, and not any specific content common choices for majors in the discipline to take as their for the next course, so that it is easy for students who are first course. experienced programmers to skip CS 0.5. If anything, beginning CS majors have a wider range of An additional reason to choose the Georgia Tech course backgrounds than beginning chemistry or math majors. Cer- is that attracting and retaining more women students was tainly at our school, we have: (1) a majority of CS majors a specific design goal of the Georgia Tech course. We too who have had relatively little, occasionally zero, program- hope to increase our retention of women. ming background, and (2) a substantial minority with a moderate to significant programming background. We imag- ine that this mix of beginning CS majors is typical for the 3. OUR CS 0.5 IMPLEMENTATION large number of schools that have selective but not highly selective admissions. 3.1 Before our changes These two groups create trouble when they are placed in Prior to Spring 2005, at our school, we used a two-course the same classroom for the same first-semester course: the introductory sequence that was somewhat based on this majority with little background are intimidated, and the mi- CS 0.5 idea.