Introduction to ANALYSIS

Why a person should not fear

Statistics

Even babies can love statistics…..

And even professors lovebabies…

Statistics is a way to get INFORMATION from data.

It may look complicated….

London Heathrow Airport

http://finance.yahoo.com/q?s=^DJI

http://www.measuringworth.com/uscompare/

http://www.x-rates.com/d/CAD/CNY/graph120.html

Some other statistics….

http://en.wikipedia.org/wiki/Statistics

Let’s take a look at what statistics are and what they do.

Charles Darwin1809-1882

Francis Galton1822-1911

Charles Spearman1863-1945

Karl Pearson1857-1936

History

Statistics:Getting information from data.

Who (what) are we studying?Population 1. Census 2. Sample

Statistics:Getting information from data.

Who (what) are we studying?Population 1. Census 2. Sample

a. Describeb. Infer

Statistics:Getting information from data.

Who (what) are we studying?Population Sample

Two types of analysis 1. Descriptive 2. Inferential

Probability

Statistics:Getting information from data.

Inferential The Probability that what we find in the Sample will apply to the whole Population.

Statistics:Getting information from data. Inferential Whenever a sample is utilized, there will always be a “sampling error.”

Statistics:Getting information from data. Inferential Whenever a sample is utilized, there will always be a “sampling error.”

That “sampling error” will increase as thevariability of the measure increases.

That “sampling error” will decrease as thesize of the sample increases.

Statistics:Getting information from data. Inferential The “sampling error.”

SE nx /

Most inferential statistics are simply the number of sampling errors a finding is from what was expected.

TestF ind ing Expecta tion

Sam plingE rror

THIS is the universal statistic….

TestF ind ing Expecta tion

Sam plingE rror

The universal statistic….

For example, the t-test is:

tx

n

0

0

Or:

TestF ind ing Expecta tion

Sam plingE rror

Ferguson’s Epitaph for a Statistician

With no applause from saint or devilHe was significant at the .05 level.He squeezed life’s data, but when doneHe failed to reach the .01.

Fergusons, G. A. (1981). Statistical Analysis in Psychology and Education(5th Ed.). McGraw Hill: New York.