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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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