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Blackboards, PowerPoint and Tablet PCs in the Classroom
Lecturer, Department of Physics
University of Toronto
Collaborators: David Harrison, Ruxandra Serbanescu
Talk OutlineTalk Outline PowerPoint versus Tablet / PowerPoint versus Tablet /
Blackboard Blackboard How we process visual How we process visual
informationinformation The advantage of the large field The advantage of the large field
of view of a blackboardof view of a blackboard When a Tablet PC is appropriateWhen a Tablet PC is appropriate Case Studies: Classes of 1000, Case Studies: Classes of 1000,
35, and 85 students35, and 85 students
Our experience in a 1700 seat auditorium
We taught calculus-based physics to 900 students in one huge section
Big central screen, two side screens Tried pure Powerpoint for one quarter Other 3 quarters we used Tablet PC on central
screen for real time development Major results, images on side screens Student survey showed preference for Tablet PC
method “Medium Pen” was more readable than “Fine Pen”
Teaching Physics in a 1700 Student Auditorium
This Talk is Canned
“Students make it clear that simply replacing the use of the blackboard by a PowerPoint presentation offers them the opportunity to sleep in the dark…”
“… even awake, they miss a key element in the learning process: observing a professor think in real time, as he or she develops material step by step.”
- quotes from U of T Academic Planning Document, Office of the Vice President and Provost, “Stepping Up: 2004 – 2010”
PowerPoint So why am I using it????! The information I’m delivering is descriptive,
result-based (…as opposed to analytical or method-based) Audience is familiar with the context You’ve seen this kind of stuff before! You want me to hurry up and tell you the end
result! PowerPoint is not the best way to teach new,
long argument-based material to an unfamiliar audience.
SUCKS!
Our experience in a 100 seat classroom – smaller class
We taught second year physics to 35 students
14 lectures: Tablet PC presentation, using PowerPoint as well as real-time notes using “digital ink”
21 lectures: Blackboard presentation, plus Tablet PC PowerPoint on the side-screen
Student survey showed blackboard-focused method was preferred
How We Process Visual Information
The visual field has three regions: Foveal - central 2 degrees of our gaze Parafoveal - extends 5 degrees out from centre Peripheral - region beyond parafovea
Studies of eye movements show: Our eyes remain still during fixations (0.2 – 0.3
seconds) Our eyes move very quickly during unconscious
saccades (30-50 milliseconds)
How We Process Visual Information
When reading, 10-15% of saccades are regressions.
Regressive saccades increase with complexity of the text.
Sometimes readers jump back many lines.Very large regressive saccades involve
spatial memory. If previous text is no longer in the visual If previous text is no longer in the visual
field, reading becomes more difficult.field, reading becomes more difficult.
How We Process Visual Information
When reading, 10-15% of saccades are regressions.
Regressive saccades increase with complexity of the text.
Sometimes readers jump back many lines.
Very large regressive saccades involve spatial memory.
If previous text is no longer in If previous text is no longer in the visual field, reading the visual field, reading becomes more difficult.becomes more difficult.
The visual field has three regions: Foveal - central 2 degrees of
our gaze Parafoveal - extends 5 degrees
out from centre Peripheral - region beyond
parafovea Studies of eye movements show:
Our eyes remain still during fixations (0.2 – 0.3 seconds)
Our eyes move very quickly during unconscious saccades (30-50 milliseconds)
…maybe I should have presented it this way?
• Blackboards in traditional classrooms have multiple panels
• Field of view is much larger than a single screen
• Much more text is visible at once
• Larger regressive saccades are possible
•Multiple panels can be planned to display one argument
•Students can review the argument as a whole.
Advantages of Blackboards
Comparing Visual Fields
Sheet of Paper, held 32 cm away from eyes:
17 x 23 degrees
Back of 100 seat classroom (9 m away):
Back of 200 seat classroom (15 m away):
Back of 1700 seat auditorium (about 60 m away):
4 blackboard panels, each 2.2 x 1.1 m
Projection Screen in room
All pictures drawn to the same angular scale
7x5m screen
Visual Fields are Not the Whole Story
Readability of writing depends mainly on• Thickness of strokes
• Distance of reader from board
Readability also depends on• Size of letters
• Lighting on board
• Cleanliness of board
Distance of student from the board should not exceed about 10 m
BUT:
Our experience in a 200 seat classroom – medium class
We taught Physics for the Humanities to 85 students
Most lectures: Tablet PC presentation, with occasional window-switches to images and animations
1 lecture: Blackboard presentation Student survey showed strong preference
for Tablet PC. Students said it was “more readable”.
200 Student Classroom
0
5
10
15
20
25
30
3 5 7 9 11 13 15 17
Distance from the Blackboard (metres)
Nu
mb
er
of
Se
ats
Easily readable
readable Difficult to read
Blackboard Visibility
View from the back of a 200 seat classroom, 15 m away
Whiteboard or Blackboard Tablet PC
Conclusions
PowerPoint may not be the best way to present long arguments to a student audience.
Blackboards offer: Large field of view – easier to read and process text Real time development of material
Check readability of your presentation method from the back row!
When blackboard is too distant to read, Tablet PC offers a readable alternative – but field of view is sacrificed.
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