Effective Presentations

The purpose of a presentation is the transfer of information, whether for didactic or persuasive purposes.

The presenter’s obligation is to provide sufficient information to:– advance the discourse,– not distort or exaggerate the data,– make the data and statistics coherent, and– map or describe complicated scenarios clearly.

What is a Presentation?

General Presentation Guidelines

Know your material – practice your presentation to increase your confidence.

Include citations where appropriate (this aids credibility).

Use complete sentences and avoid abbreviations. Abbreviations lead to forgetfulness and possibly a loss of confidence during the presentation.

Induce the audience to think about your material not your PowerPoint skills.

Promote your topic – information that you do not cover is NOT your presentation so why dwell on it?

Use a spelling checker and still proofread!

My Research Topic

• My proposed research will increase pubic awareness of a grave issue.

• My research will cover a lot of areas:– The issue and it’s consequences– The people and there problems– Cures

An outline by itself is not a presentation; outlines do not show the relationships, assumptions or the analytic structure of the reasoning between the outline items.

Do not compromise the amount of information that is needed to promote your topic.

The hierarchical outline structure of PowerPoint unfortunately promotes maintaining an outline structure and the use of bullets lists which are a poor information transfer mechanism.

The notion that “outlines are easier to follow” becomes nonsensical after several slides of unrelated bullets lists with ensuing levels of indentation.

The Use of Outlines

Corporate Plan for Fiscal 2007

• Increase market share by 25%.• Increase profit by 30%.• Increase new-product introductions to ten a

year.

Tufte, The Cognitive Style of PowerPoint, 2004, p. 6.

Graphics are not just for presentations. Seeing the problem space or data set often aids our understanding of the material and encourages new ways to view the problem and/or data. This is a tool!

One glance, a lot of information. Show a lot of data in a relatively small space to reveal relationships.

There needs be no relationship between the density of information, especially graphic, and the presenter’s vocalizations, which only need to highlight important features.

Graphical Notions

Content-free abstract diagramSource: Harold Pollack

Hospital A

Patient Hospital B

Hospital C

Admit toNICU

Do NotAdmit to

NICU

Admit toNICU

Admit toNICU

Do NotAdmit to

NICU

Do NotAdmit to

NICU

outcome

outcome

outcome

outcome

outcome

outcome

outcome

outcome

outcome

No NICU

No NICU

No NICU

Patient FlowModel

EntryModel

NICU Admission

Model* Several levels of NICU offerings will be measured. This Figure is simplified to ignore transfers. The analysis will adjust for transfers.

MortalityModel

Figure 1Offe

r

NICU

Services*

Offer

NICU

Services*

Offer

NICU

Services*

Source: Harold Pollack

Graphic presentation of data is used to promote the communication of complex quantitative, multivariate and/or relational ideas. Often, scenarios that are hard to explain verbally are easier to explain graphically.

The need to disclose complete information and to provide correct source citations is required for both graphical and textual information.

The best choice of a graphic to be used is one which provides the greatest amount of information at a glance.

The graphic used should promote thinking about the information imparted and not the design or the technology used for the graphic.

Graphical Excellence

Napoleon’s March to Moscow

Charles Minard, Carte Figurative des pertes successives en hommesde l’Armée Françasise dans la campagne de Russie 1812-1813, 1869.

Data MappingExample of a Southside Cluster With no

Major Player Grocery Coverage

Source: Mari Gallagher, Chain Reaction: Income, Race, and Access To Chicago’sMajor Player Grocers, The Partnership for New Communities, Chicago, 2005.

Dr. John Snow, Cholera Epidemic in London, 1854.

Graphing Data

Data graphing is an important tool to guide our understanding of the data and allow us to view the data in different ways.

By applying different graphing techniques to the same set of data and by asking ourselves different questions of the data we can, perhaps, uncover aspects of our research we had not anticipated.

The same techniques can be used in a presentation to encourage understanding and constructive feed-back.

Graphic Misuse

Graphical devices are very powerful tools and easy to misuse.

The use of chartjunk and clipart, for example, plays at a basic psychological level to take our mind away from the actual data presented.

We are somewhat on guard when looking at what we know or suspect to be an advertisement, but tend not to have the same defense mechanism in place in business, research or educational settings.

The argument: “for a right cause” is not a valid justification for misrepresenting the data.

Confusing Numerical Data with Graphic Area

Source: Los Angeles Times, August 5, 1979, p. 3.

Proper Distortions or AdjustmentsTo properly compare data sets when an important attribute

is quite different in each set, an adjustment in the attribute is quite helpful.

Age-adjustment facilitates the comparison of two populations with different age curves.

Inflation-adjustments facilitate understanding an implicit or explicit monetary time line.

Such adjustments can be applied over a wide variety of attributes, age, size, area, etc.

Always adjust for inflation and think in terms of per-capita numbers.

When an adjustment is used, say so!

Data Table

Race Deaths/1000

Black 1300

White 1100

Amer. Ind. 800

Hispanic 800

Asian/PI 600

Age-Adjusted Male Mortality Rates by Race/Ethnicity, 2001

Source: National Center for Health Statistical Reports, Vol. 52No. 3, Sept. 18, 2003, table 1.

0

200

400

600

800

1000

1200

1400

Black White Am. Ind. Hispanic Asian/PI

MaleFemale

Dea

ths

per

100,

000

Per

sons

Source: National Center for Health Statistical Reports, Vol. 52No. 3, Sept. 18, 2003, tables 1 & 2.

Age-Adjusted Mortality Rates by Race/Ethnicity and Gender, 2001

1300

800 800

600

920

700

560

410

1100

600

0

200

400

600

800

1000

1200

1400

Black White Am. Ind. Hispanic Asian/PI

Dea

ths

per

100

,000

P

erso

ns

Source: National Center for Health Statistical Reports, Vol. 52No. 3, Sept. 18, 2003, tables 1 & 2.

M

M

M

F

FF

MF

M

F

Age-Adjusted Mortality Rates by Race/Ethnicity and Gender, 2001

Time-Series Graphs

Source: Harold Pollack

The essential question of quantitative thinking is: “Compared to What?”

Connecticut Traffic Deaths,Before (1955) and After (1956)Stricter Enforcement by the PoliceAgainst Cars Exceeding Speed LimitSynthesized data used

Adapted from: Donald T. Campbell an H. Laurence Ross, “The Connecticut Crackdown On Speeding: “Time Series Data in Quasi-Experimental Analysis,” Tufte, ed., The Qualitative Analysis of Social Problems, 1970, p. 113.

320

310

280

290

300

1955 1956

Sure looks like a decrease to me!

Expanded Year Comparison

200

225

250

275

300

325

1951 1952 1953 1954 1955 1956 1957 1958 1959

Connecticut Traffic Deaths,1951-1959Synthesized data used

Source: Ibid. p.115.

Treatment

Finally, a Multivariate Comparison

6

7

8

9

10

11

12

13

14

15

16

17

1951 1952 1953 1954 1955 1956 1957 1958 1959

Traffic Deaths per 100,000Persons in Connecticut,Massachusetts, Rhode Island,And New York, 1951-1959Synthesized data used

Source: Ibid., p. 118.

N.J.

N.Y.

CONN.

R.I.

MASS.

Scatterplots

Scatterplots are useful for examining data sets over two or more related variables and for examining different set of data over those variables. For example:– Data correlation– Positive or negative relationships between variables– Non-linear patterns– Spread of data– outliers

Scatterplots

http://www.statcan.ca/english/edu/power/ch9/scattergraphs/scatter.htm

Positive or direct relationship Negative or inverse relationship

Very low or zero correlationExamine the outlier

Scatterplots

No relationship

Random

Source: Ibid.

How Do We Value a Presentation?

“Presentations largely stand or fall depending on the quality, relevance and integrity of the content.” Edward Tufte, “The Cognitive Style of PowerPoint,” 2003.

The same best practices used to create a presentation can and should be used to critique and experience a presentation.

A good presentation lives on after the presentation event. Unfortunately, a bad presentation lives on also.