Transcript Document

Effective Visual Aids
Eye
Maximum Winds are ~1 km above the surface
MM5 Simulation of Hurricane Andrew
Earth Science Seminar
Courtesy of Da-Lin Zhang at Univ. Maryland
M. D. Eastin
Effective Visual Aids
Know your Audience and the Purpose for your visual aids:
One-time presentation at a scientific meeting?
One-time presentation to a local group (non-scientific)?
Lecture and reference material for a group?
Earth Science Seminar
M. D. Eastin
Effective Visual Aids
Limit the Text and Maximize the Imagery
Each slide should contain only one figure or table with a few lines of text
to illustrate one idea / concept
General Rule: Readability is maximized by following the “7 x 7 Rule”: No more
that seven words per line and 7 lines per slide
Earth Science Seminar
M. D. Eastin
Effective Visual Aids
Limit the Text and Maximize the Imagery
The global mean radiative forcing experienced by the Earth system can be
divided into many categories. For each, we can approximate the sign and
magnitude of the forcing, but at a variety of confidence levels.
• Long-lived Greenhouse Gases (CO2, NO2, etc): Produce between +0.34 and +1.66 W/m 2 of forcing on
the global scale and we have a high level of scientific understanding (i.e. confidence) in this estimate
• Ozone: Stratospheric ozone produces a -0.05 W/m2 of forcing, and tropospheric ozone produces +0.35
W/m2 on the global scale and we have a medium level of scientific understanding.
• Stratospheric Water Vapor and Methane: Produces +0.07 W/m2 of forcing on the global scale and we
have a low level of scientific understanding in this estimate
• Surface Albedo: Produces between -0.2 and +0.1 W/m2 of forcing on the regional scale and we have a
medium-low level of scientific confidence in this estimate
• Aerosols: Produce between -0.5 and -0.7 W/m2 of forcing on the global scale and we have a low level
of scientific understanding in this estimate
• Linear Contrails: Produce +0.01 W/m2 of forcing on the regional scale and we have a low level of
scientific confidence in this estimate
Earth Science Seminar
M. D. Eastin
Effective Visual Aids
Limit the Text and Maximize the Imagery
Earth Science Seminar
M. D. Eastin
Effective Visual Aids
Visual aids should be readable for all audience members:
General Rule: If you can read all aspect of the slide on the computer screen
when standing 4-5 feet away, then the font size is adequate
Avoid large (>36) and small (<16) font sizes
Can you see me now
Can you see me now
Can you see me now
Earth Science Seminar
M. D. Eastin
Effective Visual Aids
Use Color Effectively:
Colors can be used to emphasize a particular point
Colors can be used to distinguish between two categories: Warm and Cold
Use “cool’ colors (blues and greens) for backgrounds
Use “warm” colors (reds and yellows) for foreground
GOOD
Shows warm
foreground color
on cool
background color
BAD
Shows cool
foreground color
on warm
background color
White backgrounds with black text can cause eye strain…
Earth Science Seminar
M. D. Eastin
Effective Visual Aids
Visual aids should look professional:
Earth Science Seminar
M. D. Eastin
Effective Visual Aids
Do not show “corny” images
Do not use ClipArt
Imagery should illustrate / demonstrate a familiar concept
Imagery should supplement your oral presentation
Earth Science Seminar
M. D. Eastin
Effective Visual Aids
Avoid “grainy” images
Scan a higher quality image
Search the internet for adapted versions
Contact the author to obtain an original
Adapt the figure yourself
From Landsea and Gray (1993)
Earth Science Seminar
M. D. Eastin
Effective Visual Aids
Avoid distracting images:
Air Motion
L
Earth Science Seminar
Pressure
Gradient
Force
Centrifugal
Force
Coriolis
Force
M. D. Eastin
Non-Effective Visual Aids
Avoid video clips that are too long or move too fast:
The Last Image
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Bad Movie
M. D. Eastin
Non-Effective Visual Aids
Avoid copyright theft
Easy: Simply acknowledge your source (either on the slide or verbally)
Note: Use of imagery and video for educational purpose is permitted by law
if no more than 10% of the original content is shown and no profit is
gained from its showing
Photograph courtesy of Brian McNoldy
Earth Science Seminar
From Bluestein (1993)
M. D. Eastin
Effective Visual Aids
Avoid too many slides:
General Rule: One slide per minute in a well rehearsed presentation
15 minute presentations should not have more than 15 slides
Too many slides result in long presentations that are often ended abruptly.
Nobody likes a long presentation…
Earth Science Seminar
M. D. Eastin
Example: An Effective Slide
Downslope Winds:
Chinook Winds:
• Temperature of the downslope flowing
air is warmer than the air it replaces
• Warming winds → dry adiabatic descent
Examples:
• Santa Ana (CA)
• Sundowner (Santa Barbara, CA)
• Föhn (Alps)
• zonda and pulche (Andes)
• kachachan (Sri Lanka)
Bora Winds:
• Temperature of the downslope flowing
air is colder than the air it replaces
• Cooling winds → evaporational cooling
Earth Science Seminar
M. D. Eastin
Examle: An Effective Slide
Mountain Wave Clouds:
• If the air parcel forced aloft is moist enough
to achieve saturation (or cloud drops form)
• Also called “lenticular” clouds
Lenticular Clouds
θ+Δθ
θ
EL
• Multiple rows of clouds can form
downstream of a mountain range
• The cloud rows are often oriented
parallel to the mountain range
Earth Science Seminar
M. D. Eastin
Example: An Effective Slide
Tornadoes form from the titling and
stretching of horizontal vorticity by a
strong updraft
Earth Science Seminar
M. D. Eastin