1. 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

2. 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

3. 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

4. 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)

5. 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

6. 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

7. 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

8. Observation Study

9. 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 = minutes
3 sessions
Algorithm analysis
Sorting
Graphs

10. 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

11. Questionnaires

12. 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)

13. 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)

14. 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

15. 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

16. Exam Results

17. 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.
TDDC 39 29 10 6
3.48
19 %
TDDC 19 42 21
3.41
28 %
TDDC 59 25 8 2
3.34
10 %
TDDC 64 27 11 1
3.33
12 %
TDDD 71 30 15
3.51
39 %

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

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

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

21. A Few Quotes

22. 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!”

23. 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.”

24. 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.”

25. Tommy Färnqvist