Visual Aids for Oral Communication Source: Denis Coulombier

Exchange of information Transform –data -> information -> knowledge Share –Paper (reports, articles) –Oral (presentations) Does our message come across?

Digital versus analog US pedestrians Pedestrian crossing X = cross ! Digital pedestrianAnalog pedestrian

BelgiumFrance Burma SpainZimbabwe Analog pedestrians from around the world Russia

Germany US Spain France Spain Italy "Rolling stones" from around the world

Distribution of signs by number of tumbling stones Number of tumbling stones Number of countries Belgium Germany Chile Ecuador Argentina Madeira

Distribution of signs by number of tumbling stones Number of tumbling stones Number of countries Belgium Germany Chile Ecuador Argentina Madeira Digital or analog ?

Preparation of visual aids Text first, then visual aids The less fancy, the better Always related to what you say

Two types of visual aids Visual data –digital: tables –analog: graphs, charts, maps Visual reinforcement –bullet lists

Interacting with visual aids Visual data: Give them the floor! Visual reinforcements: Leave them alone! Use the pointer appropriately Do not forget the audience

Visual data Tables, charts, maps The simpler the better Digital or analog ? Walk the public through

Food Specific Attack Rates, Outbreak of Salmonellosis, Prison X, Dover, Delaware, September 1992

Outbreak of Salmonellosis in a Prison, Delaware, 09/1992 Food Specific Relative Risks, Saturday September 12, Lunch ¦ ¦ ¦ ¦ ¦ ¦ ¦ ¦ Chicken Salad Bread Lettuce Leaves Sliced Tomatoes Pear Halves Iced Tea Margarine Vegetable Soup Food Relative Risk (log scale)

Graphical visual data Graphs, charts and maps One point per slide No 3D Appropriate color palette

Characteristics of colors BrightnessHue QuantitativeQualitative

Palette for a quantitative variable  Gradient of grey  Light-dark palette

Palette for a qualitative classification variable sex, socioeconomic status,...  Hue palette  Pattern palette

How to select a color or pattern 2 colors : 3 colors : or

AIDS Annual Rates per 100,000 Population for Cases Reported May 1990 through April 1991

Visual reinforcements: bullet lists Use keywords < than 12 lines < 5 words per line Break line properly

Methods The karaoke slide We conducted a retrospective cohort survey including all people attending the visit of the park A case was defined as a papular or papulo-vesicular pruritic rash, among participants, 12 hours or more after the exposition to seawater

Methods Survey –retrospective cohort –all participants Case definition –rash (papular or papulo-vesicular) –> 12 hours after exposition

Effective text attributes Sans serif font Bold type Lower case letters Good contrast Serif font Normal type UPPER CASE LETTERS Poor contrast PreferAvoid

INEFFECTIVE TEXT ATTRIBUTES SERIF FONT THIN FONT UPPER CASE LETTERS POOR CONTRAST

Ineffective text attributes : the bar code font

Poor contrast

Small font