The document describes research testing a new visual discussion forum interface designed to address the problem of "new post bias" in online discussions. The visual interface displays discussion threads in a tree structure and colors posts as read/unread. 7 students participated in discussions using both the visual and a typical text-based interface. Results showed students were more active in selecting threads and tended to read from higher to lower level posts in the visual interface, reducing negative effects of only reading new posts. However, limitations included a lack of data from the text-based forum. Future work could involve testing the interface in authentic settings and investigating its impact on student replying patterns.

1. Design, Implementation and Testing of
a Visual Discussion Forum
to Address New Post Bias
Farshid Marbouti
fmarbout@sfu.ca
Spring 2012

2. Outline
• Introducing New Post Bias
• Designing a new visual interface
• Testing of the visual interface
• Conclusion

3. Typical Online Discussion Forum
• Text-based
• Linear
• Threaded
• Asynchronous

4. Shortcomings
• Discussions do not converge to a conclusion
(Hewitt, 2001)
• Fractured and incoherent conversations (Herring,
1999; Reyes & Tchounikine, 2003)
• A low level of interactivity among learners
(Thomas, 2002)
• Student difficulties in deciding which posts to read
and reply to in a highly branched discussion
(Hewitt, 2003)

5. New Post Bias (NPB)
• Reading only new posts
– e.g. 82% of posts read were new (Hewitt, 2003)
• Replying to the most recent posts
– e.g. 65% of replies are made in 24H (Hewitt, 2003)
• Why NPB is a problem?
– Reading only new/scattered posts results in no or
limited understanding of the discussion
• Educational Consequences (Hewitt, 2005)
– Unintentional death of threads
– Unintentional drift of the discussion topic
– Ignoring synthesizing or summarizing tasks
– Ignoring difficult questions

6. Design Challenge
• One cause of NPB is the linear presentation of
threads and posts via text-based interface (Hewitt,
2003; Swan, 2004)
• A possible solution is highlighting the structure of
the discussion via a visual interface (Kear, 2001; Hewitt,
2005)
• Questions for designing a new interface. What is:
– An appropriate method to present the structure of the
discussion?
– An appropriate method to illustrate posts as read or
unread?

7. Presenting Structure of the Discussion
• Tree structure
• Prior studies used tree structure in discussion work
– e.g. Hara, Bonk & Angeli, 2000; Aviv, Erlich, Ravid, &
Geva, 2003; Scardamalia, 2004; Teplovs, 2008; Wise &
Padmanabhan, 2009
• Match between tree and discussion structure
– Node  Post
– Link  Reply

8. Presenting Structure of the Discussion

9. Illustrating Posts as New/Read

10. The Designed Visual Forum

11. Implementation

12. Testing of the new interface
Research Questions
• How does the visual forum change students’
reading patterns regarding which threads to
visit and which posts to read?
• How does the visual forum influence
students’ behaviour in reading new posts?

13. Methodology
• Authentic task
• Record interactions and feedback
• Hybrid Design (Forde, 2008)
– Students participated in an online discussion via a
text-based forum for a course
– Asked students to participate in the same discussion
via the new visual forum
– Comparison case studies

14. Participants/Setting
• Course/Discussion
– Masters-level course, offering of two years ago
– 10 discussions, each 1 week long
– Discussion worth was 30% of the grade
• Participants
– 7 (4 female, 3 male) out of 15
– 1 student graduated, 6 students at the end of
their masters program

15. Task / Data Collection
• Total time ~75 min
• Read a summary of the selected week reading
• Participated in two sessions with a 10-min break
– Screen capturing and clickstream data
– Think-aloud data
• 1st Session: midway through the discussion
– 24 posts (out of 39), ~15 minute
• 2nd Session: at the end of the discussion
– All 39 posts, ~25 min
• Fill out a short online survey
• Logged data from the course

16. Results - Survey
Strongly
Disagree
Strongly
Agree

17. Results - Survey
• Useful features
– Visual design and layout
– Integrated read and reply box
– Reset button
• Downsides
– Movements
– Not displaying full posts’ subjects
– Missing authors’ names

18. Reading Patterns: Visiting Threads
Visual Forum
Text-based
Forum
Actively selected
threads
5 students 2 students
Let the interface
decide
2 students
(Counter) Clockwise
Pattern
5 students
Linear Pattern

19. Visual Interface: Clockwise Pattern

20. Visual Interface: Actively Selective Threads

21. Text-based Interface: Linear Pattern

22. Text-based Interface: Active Selection

23. Reading Patterns: Reading Posts
Visual Forum
Text-based
Forum
Read higher-level
to lower-level
posts
5 students
(Radial Pattern)
4 students
(Linear Pattern)
Decided based on
other factors
2 students
(Mixed Patterns)
3 students
(No Pattern)

24. Visual Interface: Radial Pattern

25. Text-based Interface: Linear Pattern

26. Reading New Posts: Last Session
Visual Forum
Text-based
Forum
Re-read posts before
reading new ones
2 students
Read new higher-level posts
then new lower-level ones
4 students 1 student
Read new posts (mostly
skipped higher-level ones)
1 student 2 students
Read only new replies to
his/her posts
2 students
Only re-read posts 1 student

27. Conclusion
• Overall student feedback was positive.
• In both forums students showed interest in
reading new posts.
• In the visual forum students were more active
in selecting which threads to visit.
• In the visual forum students (re)read higher-
level posts before the new lower-level ones.
• Negative consequences of NPB reduced by
visual presentation of the discussion.

28. Limitations
• Comparability of sessions
– Number
– Duration
– Time between sessions
• Authenticity of the assigned task
• Lack of observational data for the text-based
forum

29. Implications for Future Work
• Design
– Displaying authors’ names
– Finding a post
– Illustrating different posts (e.g. self, instructor)
• Research
– Test in a naturalistic setting
– Task specific tests
– Investigating students’ replying patterns

30. Thank you!
Farshid Marbouti
fmarbout@sfu.ca
Spring 2012

31. Emily

32. David

33. Mike

34. Nicole

35. Steve

36. Amanda

37. Christine

38. Knowledge Forum

39. Implications for Practice
• Students rely on forum/interface in deciding
which posts to read
• Instructors should purposefully choose a forum
that pedagogically support the assigned task
• Instructors should assign tasks and roles in a
discussion