Choosing a statistical

1
Choosing a statistical What are you trying to
do?



2
Describe a sample or population
Measures of Central Tendency Mean, Median,
Mode Measures of Dispersion
Range, standard deviation
3
Infer about a population from a sample What
level of data ? Interval
Ordinal Nominal


Chi Square


Goodness of fit

Nonparametric tests
Infer about a population from a sample What
level of data ?
Interval
Ordinal Nominal





4
Interval Ordinal Nominal


Chi Square


Goodness of fit
5
Interval Ordinal Nominal




Nonparametric
tests
Mann Whitney U (2 samples) Kruskal Wallace H
Test (3 or more samples)
6
Interval Ordinal
Nominal Relationship or Difference
?
7
Relationship or
Difference? Pearson r correlation 2
dependent variables
8
Relationship or Difference
How many
variables?

9
How many variables?
One Variable Two
Variables
10
One
Variable or Two
Variables 2 way ANOVA
11
One Variable or Two
Variables How many groups?

12
How many groups? One
group Two groups More

than two Groups
13
One group Two groups More
than
two Groups t test for single
? is known ?
is unknown
14
One group Two groups More than

two Groups
t test for 2 samples

independent samples
or
matched samples

15
One group Two groups More than

two Groups
One way ANOVA
3
or more levels
of the ind. Var.