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.