Supporting Active Learning by Introducing an Interactive Teaching Tool in a Data Structures and Algorithms Course Tommy Färnqvist 47th ACM Technical Symposium on Computer Science Education March 5, 2016

Project members and co-authors SIGCSE 2016 Tommy Färnqvist March 5, 2016 Project members and co-authors Tommy Färnqvist, Linköping University (PI) Fredrik Heintz, Linköping University Patrick Lambrix, Linköping University Linda Mannila, Åbo Akademi University and Linköping University Chunyan Wang, Linköping University

Data Structures and Algorithms SIGCSE 2016 Tommy Färnqvist March 5, 2016 Data Structures and Algorithms Study of basic building blocks in programming Abstract data types Sorting algorithms Computational complexity Current courses Lectures, labs, exercise sessions Visualization of algorithms on course web pages

Current Courses Lack of practice Too few problems per topic SIGCSE 2016 Tommy Färnqvist March 5, 2016 Current Courses Lack of practice Too few problems per topic Assignments aren’t comprehensive Feedback Disconnected (received long after submission) Variable quality (depends on grader) Sometimes none provided (especially if homework is optional)

Goals Introduce active learning continuous examination and feedback SIGCSE 2016 Tommy Färnqvist March 5, 2016 Goals Introduce active learning continuous examination and feedback in a data structures and algorithms course by using an e-book that provides interactive examples and visualizations many exercises automatic assessment and immediate feedback

SIGCSE 2016 Tommy Färnqvist March 5, 2016 OpenDSA A collection of open source materials combining textbook-quality text with interactive examples and randomly generated instances of exercises Unlimited amounts of practice Automatic assessment and immediate feedback Free and open source Interactive, engaging, and dynamic material Content continuously updated and refined

SIGCSE 2016 Tommy Färnqvist March 5, 2016 Project OpenDSA used in TDDD86 Data Structures, Algorithms, and Programming Language Paradigms 130 CS major students in fall 2014 OpenDSA assigned for (extensive) homework and for (part of) final exam Data collection Log data from the OpenDSA system Exam results Questionnaires Observation study

Observation Study

Method 6 students 2 observers One session = 25 + 5 minutes 3 sessions SIGCSE 2016 Tommy Färnqvist March 5, 2016 Method 6 students 2 observers One session = 25 + 5 minutes 3 sessions Algorithm analysis Sorting Graphs

Results Students prefer OpenDSA over traditional textbook SIGCSE 2016 Tommy Färnqvist March 5, 2016 Results Students prefer OpenDSA over traditional textbook Glossary, visualizations, and exercises (interactive parts of tool) are appreciated and help understanding Makes students work during the course Several students skip text Guess answer to exercises; Interaction with the visualizations without learning

Questionnaires

Online questionnaires SIGCSE 2016 Tommy Färnqvist March 5, 2016 Online questionnaires Survey 1 – before course 42% of students responded (54/130) Survey 2 – after course (before final exam) 27% of students responded (35/130)

Experience with OpenDSA SIGCSE 2016 Tommy Färnqvist March 5, 2016 Experience with OpenDSA How many students actually used the material? 62% have studied the theory parts of OpenDSA at least once per week (31% more than once a week) 54% have completed one or more exercises in OpenDSA at least once each week (20% more than once a week)

Experience with OpenDSA SIGCSE 2016 Tommy Färnqvist March 5, 2016 Experience with OpenDSA How satisfied are the students with the material? 49% of respondents very satisfied, 40% satisfied 71% felt their expectations were met 91% prefer OpenDSA over a printed textbook

Experience with OpenDSA SIGCSE 2016 Tommy Färnqvist March 5, 2016 Experience with OpenDSA Some mentioned benefits Always accessible Animations and interactivity increase understanding Quizzes make it possible to check own understanding Some mentioned drawbacks Some textual parts too long Not completely bug free Layout could be improved to better highlight relevant parts of material

Exam Results

Exam Results Class U 3 4 5 Average Prop. TDDC70 2010 39 29 10 6 3.48 Fail Pass Pass with credit Proportion of students getting a higher than passing grade out of all students taking the exam Exam Results Pass with distinction Average passing grade Class U 3 4 5 Average Prop. TDDC70 2010 39 29 10 6 3.48 19 % TDDC70 2011 19 42 21 3.41 28 % TDDC70 2012 59 25 8 2 3.34 10 % TDDC70 2013 64 27 11 1 3.33 12 % TDDD86 2014 71 30 15 3.51 39 %

Exam Results Class U 3 4 5 Average Prop. TDDC70 2010 39 29 10 6 3.48 19 % TDDC70 2011 19 42 21 3.41 28 % TDDC70 2012 59 25 8 2 3.34 10 % TDDC70 2013 64 27 11 1 3.33 12 % TDDD86 2014 71 30 15 3.51 39 % TDDD86 2015 70 13 3.35 25%

Exam Results Class U 3 4 5 Average Prop. TDDI16 2012 19 34 9 1 3.25 16 % TDDI16 2013 22 36 14 3.31 21 % TDDI16 2014 21 27 13 3.51 27 % TDDI16 2015 (OpenDSA) 54 7 3.20

Exam Results Class U 3 4 5 Average Prop. TDDC91 2010 18 12 3.20 9 % 3.20 9 % TDDC91 2011 8 22 3.27 21 % TDDC91 2012 24 3.25 10 % TDDC91 2013 19 3.33 13 % TDDC91 2014 10 9 24 % TDDC91 2015 (OpenDSA) 13 11 3.63 52 %

A Few Quotes

OpenDSA increases understanding SIGCSE 2016 Tommy Färnqvist March 5, 2016 OpenDSA increases understanding “I have learned more in less time; it takes a lot more time to struggle through a thick book with static images compared to clicking through an animation at the pace you need depending on how well you understand the algorithm.” “After you had seen it, understanding what the text was talking about became much easier!”

OpenDSA encourages studying SIGCSE 2016 Tommy Färnqvist March 5, 2016 OpenDSA encourages studying “The way the exercises were presented in OpenDSA made me spend more time with them after reading the chapter compared to a printed textbook, which is positive!” “Since there were mandatory exercises, and quite many, I read and did the exercises in the same pace as the lectures, which made it easier to study for the exam at the end, and I had more knowledge and a better understanding.”

SIGCSE 2016 Tommy Färnqvist March 5, 2016 The main issue is bugs “The biggest problem is that there are bugs. They are a major distraction when doing exercises.” “When you get rid of the bugs this will be one of the best text books you can get. Animations in combination with text is very close to what you get from a good lecture.”

Tommy Färnqvist tommy.farnqvist@liu.se