Chapter 11- One Way ANOVA Flashcards Preview

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Flashcards in Chapter 11- One Way ANOVA Deck (31):
1

When will the F- distribution approach normal distribution?

The F distribution will approach normal distribution when there are large samples sizes

2

What other distribution is like the F-distribution?

The F distribution is like the T when there are only 2 samples

3

What is the F-statistic?

The F-Statistic is a ratio of two measures of variability

4

What are the two measures of variability with the F statistic?

Between-groups and within-groups

5

What is between-groups variance?

Between groups is the estimate of the population variance based on the spread between group means

6

What is within-groups variance?

Within groups variance estimate of the population variance based on the average variability within each group

7

How is the F-statistic calculated?

The F-statistic is calculated by dividing the between groups variance by the within groups variance

8

How do you increase the F-statistic?

The F statistic can be increased by increasing the variability between means or decreasing the variability within groups

9

What is a one-way ANOVA?

One nominal independent variable with more than 2 levels, scale dependent variable

10

What is a One Way Within Groups ANOVA?

One Way Within Groups ANOVA is more than 2 samples, composed of the same participants. Also called repeated measures

11

What is a One Way Within Groups ANOVA?

One Way Between Groups ANOVA is more than 2 samples, each composed of different people.

12

What are the assumptions of an ANOVA?

Random and independent, population distribution of dependent variable is normally distributed, and samples come from populations with same variance (homoscedasticity)

13

What is heteroscedasticity?

Heteroscedasticity is when samples come from different variances

14

What are the 6 steps of ANOVA Hypothesis Testing?

1. Identify pops, distributions, and ck assumptions
2. State null and research/alternative hypothesis
3. Determine characteristics of null distribution
4. Determine Critical Values
5. Calculate test statistic
6. Make a decision

15

How do you calculate the dfbetween?

Calculate the number of groups-1

16

How do you calculate the dfwithin?

Calculate the total number of participants - the number of groups

17

How do you calculate the dftotal?

Calculate the total participants-1

18

What is the MS and how do you get this number?

Mean Square. It is the SS divided by the degrees of freedom

19

What is the SS?

The SS is the sum of squares; its the sum of deviation scores squared

20

What is the SS total?

The SS total is the sum of all squares ignoring the separate groups

21

How do you calculate the MS between?

The MS between is calculated by dividing the SS between by the dfbetween

22

How do you calculate the MS within?

The MS within is calculated by dividing the SSwithin by the dfwithin

23

How do you calculate the F statistic after calculating the MS between and the MS within?

The F statistic is calculated by dividing the MS between by the MSwithin

24

What formula is used to calculate effect for ANOVAs?

R2

25

What is the R2 and what are the sizes?

R2 is the proportion of variance in the dependent variable that is accounted for by the independent variable. You can convert this amount to a percentage. The sizes are sm= .01, med=.06, and large is .014

26

What happens when multiple comparisons are made?

The more comparisions we do, the more likely we mare going to make a type 1 error

27

What is a post hoc test?

A post hoc test is a test used to compare multiple groups (two at a time)

28

What does the post hoc test protect from?

A post hoc test protects from inflating a type 1 error

29

When is a post hoc test conducted?

A post hoc test is only conducted if the overall F test is signifigant

30

What is the name of the most common post hoc test?

Tukey HSD

31

What is the critical value of the Tukey HSD?

Q-value +/- 3.77