Using Collaborative, Modified Peer Led Team Learning To Improve Student Success and Retention in Intro CS Maureen Biggers
Tuba Yilmaz
Monica Sweat
919 E. 10th Street, Bloomington, IN 47408
85 5th Street, Atlanta, GA 30332
801 Atlantic Drive, Atlanta, GA 30332
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ABSTRACT
1. INTRODUCTION
It is common knowledge that enrollments in computer science have plummeted and educators are challenged to find ways to engage and promote success and retention of students while maintaining standards in introductory computer science courses. This study focuses on the implementation of a collaborative, modified peer-led team learning (PLTL) instructional approach in a large sized introductory computer science course. The site is a major southeastern university in the United States where all students are required to take one of three introductory computer science classes. The course version selected for this study specifically targets computer science majors and the study spans three years of data, and involves 591 students. Students who experienced the student-centered instruction and worked in small groups facilitated by a peer leader (treatment) in years 2006-07 and 2007-08 were compared with students who experienced a traditional recitation lecture section (control) in 2005-06. The content and the course owner was the same for all three years. Quantitative data analysis show marked and statistically significant improvements in student performance, for both male and female students. These findings suggest that using undergraduate leaders to implement a peer-led team learning model can be as effective in promoting achievement and retention in computer science education as it has shown to be in math and science classes over the past several years.
Originally, the PLTL model was developed, in part, to address high attrition rates and faculty concerns about student learning in introductory chemistry courses. The model provided an environment in which students are immersed in an intellectual community, learn to communicate scientific ideas, and to work in a problem-solving team [7]. There is a rich body of literature that points to value added benefits associated with this type of ‘learner interactivity’, for all participants - ‘learner’ and ‘instructor’, employee and employer [13]. Rather than gaining a discrete body of abstract knowledge that is reapplied in later contexts, learning involves the acquisition of skills through interactivity with others. In essence, the PLTL instructional model preserves the traditional lecture and introduces a new structure, the PLTL Workshop, which requires active engagement of the students with each other as they tackle specially designed problems related to course content. NCWIT promotes PLTL as a Promising Practice for promoting success and retention of women in computing and IT. According to their report, PeerLed Team Learning (PLTL) is a collaborative and active learning technique that forms students in a course into a community of scholars and leads them to take responsibility for their learning. It involves teams of six to eight students that meet weekly in a workshop with a trained peer leader who is under direction of the instructor. During the meeting, the group engages in interesting problem-solving exercises. [11]
Categories and Subject Descriptors K 3.2 [Computer and Information Science Education] Computer Science education; Curriculum
Undergraduate students serve in the role of per leader. Rather than being an answer giver, the peer leader’s role is to guide and mentor, and to provide a structure that provides the opportunity for collaboration and group problem solving. Problems presented are designed to integrate creative problem solving with material that engages students and further develops students’ conceptual understanding of the course work. Peer leaders receive special training in collaborative learning and student leaders develop the in-class activities in coordination with the course instructor. One peer leader describes for us his perception of how planning differs from the traditional lecture to the collaborative approach being studied here: “Planning for a PLTL recitation is very different than planning a typical lecturestyle recitation. When planning a "normal" recitation, you utilize a pyramidal top-down approach - pick the main topics which need to be covered and highlight the details of each topic in a "bullet-list" fashion, throwing in the occasional example. With PLTL sessions, on the other hand, you use a spiral approach start with a detailed problem/example and as the students work together to solve a problem, they stumble upon the "learning
General Terms Design, Performance, Human Factors
Keywords Computer science education, retention, peer led team learning, student success, collaborative learning, CS1/2
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students per section, with one Peer Led Team Leader. In all cases the extra course is pass/fail and the peer leaders have received off-site training with the NSF collaborating group and have worked closely together with the intro to CS course instructor on their campus to design activities that complement course material. Overall results are very positive in terms of student success. However it seems that the ability to generalize these results is limited for three reasons: first, there is no control for student motivation of the participants who volunteer to enroll in an extra credit course; second, the actual numbers on each campus are small due to the nature of the study; and finally, the workshop is not fully integrated into the intro course as something for all enrolled students and therefore is not aligned with the ideals of PLTL in the true sense.
objectives". Using a brief formal wrap-up at the end of the session, the undergraduate Teaching Assistant (TA) – now turned PLTL leader - is able to fill in any missing pieces that the particular example didn't highlight.” The traditional PLTL Workshop approach is similar in some ways to other undergraduate student-assisted learning approaches such as supplemental instruction [3], [8], [9], study group programs [10], [12], and Emerging Scholars programs [2], [4], [6]. These collaborative problem-solving sessions are facilitated by undergraduate student leaders and often integrate learning strategies with course content. They include a training component to equip student leaders with strategies for learning and studying. How supplemental instruction and study groups function differently from the PLTL approach, however, is that typically they are not integrated within the course and do not involve the faculty member. In contrast, the PLTL workshop is integrated and is a fundamental part of the actual course that is provided to all students enrolled in the course and the course instructor collaborates with peer leaders to plan workshop activities.
This institution provided the opportunity to examine for effect in a bigger picture with a significantly larger number of students who were not volunteers by incorporating/integrating the values and practices of PLTL throughout the entire Introductory CS course. This particular course is the one that is required for CS majors and a select few other majors as well. Our goal was to examine its effect on student performance and retention. This specific course has an historical combined enrollment that exceeds 300 students each year who are primarily first year students. We do need to note that the fall 2007 experimental group did drop significantly in size due to the introduction of a new intro option for majors that used robotics.
A 2007 FIE Work In Progress paper indicated that PLTL was being promoted among institutional partners of the NSF sponsored CA-HIS Alliance (Computing Alliance of Hispanic Serving Institutions). Assessment results were pending for several institutions, though preliminary reports from UTEP were encouraging [2].
Georgia Tech is highly competitive with an admission process that is blind to ethnicity, gender, and intended major. The mean composite SAT score for the freshman class in comparison years are 1340 for 2005, 1343 for 2006, and 1356 for 2007. There is no significant difference in SAT scores for each of the three years considered in this study and consequently we did not need to control for SAT scores.
In summary, the PLTL Workshop model includes several critical components: organizational arrangements (e.g., structuring group breakouts), peer leadership and training, materials that are challenging at an appropriate level, and integration with the overall course [5]. The present study evaluates the impact of a collaborative, modified peer-led team learning environment on student performance, and retention in introductory computer science. The term “modified PLTL” approach is used in this study because there were resource constraints in place by the department. The typical PLTL luxury of 8:1 student to leader ratio was just not possible. The number of students assigned to each workshop section remained the same: fifty. The number of PLTL/TA’s remained the same: two per section. So the student leaders learned how to use breakout groups and other PLTL small group learning strategies to meet the goals of a collaborative session and the management strategy for each session was dramatically altered. What was historically known as a “recitation section” was thus transformed into a “CS Workshop” where every student enrolled in the introductory CS class was assigned to a specific meeting time and location as part of the course. Note that at this institution, there are no CS labs for the intro course.
There were two null hypotheses to explore in our analysis. First, there are no differences in student success and retention between the experimental fall 2006 and 2007 groups and the fall 2005 control group. Second, there are no gender differences with respect to success and retention between experimental and control group participants.
2.2 Pre-PLTL Course Structure Historically, the course delivery structure has been a three hour per week lecture by the course instructor and a one hour per week non-graded recitation section, taught by an Undergraduate Teaching Assistant. No lab is involved. The common format of the recitation was to re-lecture the content to the class and the Teaching Assistant served primarily as the “answer giver” when questions were asked. The style was largely one-way passive receptive communication with no collaborative element. Each recitation section was assigned 50 students, had two Teaching Assistants, and attendance was neither mandatory nor recorded.
2. METHOD 2.1 Background In Fall 2004, NSF funded a four year ITWF collaborative research grant #0420368 involving seven partnering institutions. Its focus was to study the impact of using PLTL on enrollment of women and minorities in computer science. Originally built on the Emerging Scholars model, students experiencing this approach are specially recruited on each campus and participants are required to enroll in an extra one credit course that meets in a two hour block each week. In general, class sizes are in accordance with the PLTL model having no more than ten
2.3 Procedures With financial assistance from the teaching and learning center at the site of this study 15 Teaching Assistants spent 2 days in an off site retreat in the fall 2006 to learn how to effectively deliver the PLTL model. The workshop was designed and facilitated by the course instructor and PLTL leaders who had been trained as part of the NSF cooperative grant, who had been working with a different intro course for non-majors, and who were eager to share their strategies and experiences with their peers.
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Workshop students participated in collaborative activities which took place in a variety of small group configurations throughout the semester including occasional dyads with a pair programming approach. In one Peer Leader’s words, “For every activity, I would try to come up with a way to explain whatever needed to be learned that week in workshop in a fun way. I used a lot of different approaches to try to reach out to all of my students. Some examples are playing Jeopardy, breaking codes, breaking the class into teams and having a contest for who can solve the problem the fastest, problem solving teams, and having people come up to the board to write down the answer and explain it to the rest of the class.” Activities complemented the course content and rarely did the class resume to the “old format” of lecture and peer leader as answer giver. As was true in the past, attendance was neither mandatory nor recorded, but Peer Leaders reported a sense of higher attendance with this new format in place. PLTL leaders had an on-line wiki where
corresponding and significant drop in the number of B grades earmed. There was a drop in “C’s earned” but this difference was not significant. Figure 1
they shared their session activities.
2.4 Analysis
p-value(A) = 0.001* p-value (B) = 0.001* p-value (C) = 0.09
Quantitative analyses were used to investigate the hypothesized relationships between the PLTL experience and student retention and performance. An historical comparison of retention and success rates was performed for end-of term grades for fall 2005 (control) vs. fall 2006 & 2007 (experimental). Since the course content, goals, structure and instructor were the same for each of the three years, and the freshman SAT scores are essentially the same for all three years, use of historical comparison is justified for this study. All quantitative analyses were performed using standard tests on proportions for two samples.
Figure 2 shows the comparisons according to the gender. Both genders show similar and significant positive results. These significant results were the same for both genders. Figure 2
The Workshop and recitation were both complex learning environments; thus, our unit of analysis is retention, as defined by students completing the course with a grade of “C” or better and academic success, as measured by final course grade. A total of 591 undergraduate students were enrolled in the firstsemester computer science course from 2005-07 and were included in this evaluation. All students enrolled in 2005 served as the control group (traditional recitation section). All students enrolled in 2006 and 2007 served the treatment (PLTL Workshop) group. For all three comparison years, neither participation nor attendance in the recitation portion was monitored and are therefore not part of this comparative analysis.
p-value (male) (A) = 0.001* p-value(female)(A) = 0.001* p-value (male) (B) = 0.001* p-value(female)(B) = 0.01* In the Fall of 2005, using the traditional non-PLTL approach as described above, 47 (18%) of the 267 enrolled students either withdrew (W) from the course or earned a final grade of D or F. This failure rate number is consistent with prior years’ enrollment for the intro course we are describing. The DFW rate under the new approach was significantly lower. (See Figure 3)
Chart A. Participant numbers with gender breakdown Control Experimental Female Male Total
F05 79 188 267
F06 52 181 233
F07 45 44 89
Figure 3 shows results when grades of Fall 05 (control) are compared to Fall 06/07 (experimental). “Pass” was designated if a student earned a grade of A, B, or C, and “Fail” was designated for earned grades of W, D or F. The chart indicates that the patterns did change significantly and positively when the collaborative learning model is introduced into CS1. DFW rates decreased significantly (p
