Scientific Presentations
How to (and how not to) Give an Effective Scientific
Presentation
Andrew Cornelius
Top ten fears of Americans1) Public Speaking2) Heights3) Insects4) Financial Problems5) Deep Water6) Sickness7) Death8) Flying9) Loneliness10) Dogs
Why do you need to speak? Publications lag 1-2 years behind
discovery Talks at scientific meetings are current!!
Your future job depends on talks You are evaluated by everyone as student Your talks reflect on advisor You will give candidate talks
Interviewers make conclusions in first 3 minutes
Introduction
OUTLINE
• Introduction• Experimental• Results• Discussion• Conclusions• Future Work
Outline Introduction Experimental Results Discussion Conclusions Future Work
Don’t overuse “gee whiz effects”
Make sure material is relevant
Use simple backgrounds Use “normal” fonts
At least 18 pt (24 better) – this text is 20 pt
Use “normal” colors Do not use red and green
as contrasting colors Only use for emphasis Check before using!!!
Don’t use this outline!!! 45 wasted seconds
Normal: 5 Red/Green
Color Blind: 2
Outline Before you start preparing your talk
Know your audience Know the length of your talk Know the style of your talk
Preparing the talk Choosing and organizing the content Preparing slides Don’t overdo methods part of talk
Giving the talk Grab and hold audiences attention
General information
Know your audience How large will the group be? Experts
Eliminate introductory material Can be much more focused on the
“interesting” results Novices
Assume your audience is intelligent but knows nothing
80% of material should be introductory Mixed
Most difficult 60% of material should be introductory
Length of talk 12-15 minutes
Contributed conference talks Most difficult!! Limit talk to 10 minutes Only make 2-3 points
30 minutes Invited conference talks Journal club presentations Limit talk to 20 minutes
60 minutes Invited talks Special seminars Limit talk to 50 minutes
Know the style of your talk
Persuasive Instructional
This talk!! Informative
Normal for scientific meetings Formal or informal?
Hard to time informal
Choosing and organizing the content What are trying to tell audience?
Tell them what you are going to tell them, tell them, tell them what you told them
2-3 points for 15 minute talks 3-5 points for 30 minute talks 4-6 points for 1 hour talks
Write a basic outline Make a rough draft with slides
Figure out how many slides you can use Slides without graphics should be up for at least 30
sec Slides with graphics should be up for at least 1 min
Keep it simple, stupid!!!!! Cut what is not necessary
Preparing slides with text
Use white or light color backgrounds Don’t use lists with more than 6 items
Break into multiple slides Don’t use complete sentences
Try to keep list items to 6 words or less (unlike this one!!!)
Don’t use abbreviations or acronyms
Preparing slides with graphics
Graphics add to viewer retention
Try to avoid large lists
Keep graphics simple Use white or light
colored backgrounds 10% of male
population color blind Make ALL text
readable
0 20 40 60
Recall (%)
AudienceRetention
Hear and SeeSeeHear
Talking about human error Know your audience
Intro physics students Know the length of your talk
10 minutes Know the style of your talk
Informative Choosing and organizing the content
Space travel What are trying to tell audience?
2-3 points for 15 minute talks Humans make mistakes Units are important Don’t “make” your answer agree with expectations
Figure out how many slides you can use Try to limit to 2 slides with text (beginning and end) and 5 or 6
with graphics Keep it simple (and interesting), stupid!!!!!
Human errors and space program
Space program driven by scientists Humans make mistakes Many disasters caused by human
error Never forget units in your
calculations Don’t “make” your answer agree
with expectations
Space Program Failures Project Mercury had a FORTRAN
syntax error such as DO I=1.10 (not 1,10).
Gemini V 100mi landing error, program ignored orbital motion around sun
Atlas-Agena software missing hyphen; $18.5M rocket destroyed
Aries with $1.5M payload lost: wrong resistor in guidance system
NASA HESSI shake test 10 times too strong, damaging spacecraft
Appollo 13
Tank 2 Salvaged from Apollo 10 was accidentally dropped 2”
Switch designed to run at 28 V
Apollo 13 “upgraded” to 65 V Switch burned into open
position – O tank reached 1000° F and 1000 psi
Delta II spacecraft
January 17, 1997 $55 million dollar
rocket $40 million dollar
new generation GPS satellite
“Steering” error
Titan 4A spacecraft Second most
expensive accident August 12, 1998 $1 billion ??? Payload
Top secret communications intelligence satellite
Battery power lost momentarily Veered off course Intentionally
destroyed
Space shuttle challenger
Most expensive space accident
Jan 28, 1986 $2B lost (along with
seven crew members) O-Ring failure (cold o-
rings didn’t seal and were burned by H-O mixture)
Roger Boisjoly sent memos out before
Approaching scientific problems
Formulate problem Try to find solution Measure
Carefully document findings (use units!) Compare expected value and result
If different, why? (explore all options!) Computers don’t always give right answer
NASA: Human error caused loss of Mars orbiter November 10, 1999 Web posted at: 2:25 p.m. EST (1925 GMT)
WASHINGTON (AP) -- Failure to convert English measures to metric values caused the loss of the Mars Climate Orbiter, a spacecraft that smashed into the planet instead of reaching a safe orbit, a NASA investigation concluded Wednesday.
An investigation board concluded that NASA engineers failed to convert English measures of rocket thrusts to newton, a metric system measuring rocket force. One English pound of force equals 4.45 newtons. A small difference between the two values caused the spacecraft to approach Mars at too low an altitude and the craft is thought to have smashed into the planet's atmosphere and was destroyed.
The board found that the error went undetected in ground-based computers. Also, the mission navigation's team had an imperfect understanding of how the craft was pointed in space. Additionally, the mission navigation team, the report said, was overworked and not closely supervised by independent experts.
The Mars Climate Orbiter was launched December 11, 1998, and began its long journey toward the red planet. Along the way, engineers on the ground sent instructions to the craft to fire rockets to correct its path toward Mars. It was in these rocket firings that the error occurred.
Illustration of the Mars Climate Orbiter
Mars orbiter
Conclusions Space program driven by scientists
Humans make mistakes Many disasters caused by human error
Never forget units in your calculations Almost all answers in physics use units!! Use SI units when possible
Don’t “make” your answer agree with expectations Mars orbiter could have been saved Computers are only as smart as the
programmer
Why did I show this?
Good example of choosing graphics to enhance points
Only tried to get across 3 points I placed at the 20 minute mark
Average attention span of alert audience
Principles of an effective talk
Communicate your arguments and evidence Persuade your audience that what you say is true Be interesting and entertaining Grab and hold audience’s attention
Why usegraphics?
Picture is worth many words
In this case 700 Color would enhance
The medium allows use of graphics
Maximized retention 5x higher with sight
and sound Properly cite
materialEdward R. Tufte, The Visual Display of Quantitative
Information. Graphics Press (2001)
Making a decent figure
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Bad Better
More on graphics
Only use equations if absolutely necessary
If you use equations Slow down Talk through step by
step Explain relevence
Giving the best possible talk Make eye contact Don’t have nervous tendencies
Pacing, bobbing, waving arms, jingling coins, etc.
Hold pointer still Don’t point directly at overhead on projector
Enunciate Make yourself slow down if necessary
Avoid “uh”, “like”, “um”, “okay” etc Be enthusiastic Don’t block the screen
Project as high as possible
Giving the best possible talk (cont)
Face the audience Do not read what is on your
overheads verbatim Never allow a blank screen to
flash by However, don’t leave a slide up
too long – put a black slide up if necessary
Try to relax Can be difficult
Do NOT go over allotted time Don’t end with “I guess that’s
it” Will get cut off at meetings
Know your material
Practice, practice, practice Focus on communicating, not
performing Humor good, but this isn’t stand up
Keep it simple Prepare key phrases
Okay to write out material first Write down the point to make for
each slide If you don’t have a point, eliminate
slide!!! Stay on track
Small digressions fine (shows you are paying attention to audience)
It takes three weeks to
prepare a good ad-lib speech
More advice Bring a copy of your slides
if giving a PowerPoint presentation
Fill the screen Don’t cover up portions of
overheads Don’t argue with
questioners Practice, practice, practice
Practice with slides Find someone to listen Record presentation
Video Microsoft Producer
Conclusions
Preparation is crucial Graphics enhance retention Be relaxed and (try to) keep
audience attention Finish on time The more you practice, the better
you will get
More material
Go on Google and try “scientific talk” or “scientific presentation”
Physics Today articles ONR article 10 Commandments to give a bad
talk I will make this presentation
available on my web site
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