Independent one-way ANOVA

Question 1

ANOVA

Answer 1

analysis of variance

Question 2

one-way ANOVA

Answer 2

used when we have 1 IV with MORE than 2 levels
- estimates whether the population means under the different levels of IV are different

Question 3

independent one-way ANOVA

Answer 3

between participants

Question 4

relation to t test

Answer 4

squared t-test statistic = F (one way anova result) for an IV with 2 levels

Question 5

Family wise error rate

Answer 5

the probability that at least one of a ‘family’ of comparisons, run on the same data, will result in a Type I error
…instead calculated a corrected significance level, expressing the probability of making a Type I error

c=comparisons
a= 0.05

Question 6

what do omnibus test, such as ANOVA, do?

Answer 6

control family wise error rate

Question 7

F statistic from one-way ANOVA

Answer 7

• F value close to zero, small variance between relative to within
  and vice versa

Question 8

sources of variance between IV levels for independent designs

Answer 8

• manipulation of IV
• individual differences
• experimental error (random/constant)

Question 9

sources of variance within IV levels for independent designs

Answer 9

• individual differences
• experimental error (random)

Question 10

assumptions for independent one way ANOVA

Answer 10

• normality
• homogeneity of variance
• equivalent sample size
• independence of observations

Question 11

normality

Answer 11

the DV should be normally distributed under each level of IV

Question 12

homogeneity of variance

Answer 12

the variance in the DV under each IV level should be equivalent

Question 13

what if Levene’s statistic is significant

Answer 13

use Welch F statistic to correct this
- under Robust test of equality means in SPSS out-put

Question 14

what test do we use if we greatly violate the assumptions of the one-way independent ANOVA test

Answer 14

Kruskal Wallis test

Question 15

large value of F

Answer 15

manipulation of IV has had a large effect

Question 16

SPSS output one-way independent ANOVA

Answer 16

Question 17

Model Sum of Squares (SSm)

Answer 17

sum of squared differences between IV level means and grand mean
- reflected between IV level variance

Question 18

Residual Sum of squares (SSr)

Answer 18

sum of squared differences between individual values and corresponding IV level mean
- within IV level variance

Question 19

SSm + SSr =

Answer 19

SSt
sum of squares total

Question 20

how do we calculate mean square values

Answer 20

sum of squares / df

Question 21

how do we calculate F

Answer 21

mean square value for between groups / mean square value for within groups
- variance between / variance within

Question 22

d.f. for one way ANOVA independent between IV levels

Answer 22

d.f. model = k - 1
k = number of levels of IV

Question 23

d.f. for one way ANOVA independent within IV levels

Answer 23

d.f. residual = N - k
n = total sample size
k = number of IV levels

Question 24

secondary analyses for one-way independent ANOVA

Answer 24

post-hoc tests

.. what happens after omnibus test (ANOVA)

Question 25

post-hoc tests

Answer 25

• used to analyse which IV level mean pairs differ
• only when F value is significant

Question 26

Type I error

Answer 26

risk of incorrectly rejecting null hypothesis when population means are actually not different

Question 27

Type II

Answer 27

risk of failing to reject null when population means are actually different

Question 28

choice of corrections tabel

Answer 28

don’t need to memorize

Question 29

SPSS out-put post-hoc

Answer 29

example

Question 30

significant

Answer 30

if greater than 0.05

Question 31

the two different effect sizes for ANOVA

Answer 31

• partial η^2
• Cohen’s d

Question 32

partial η^2 (Eeta)

Answer 32

how much variance in the DV is explained by the manipulation of the IV overall

Question 33

Cohen’s d

Answer 33

the magnitude of the difference between pairs of IV levels

Question 34

effect sizes

Answer 34

Question 35

small partial η^2 effect size

Answer 35

> 0.01

Question 36

medium partial η^2

Answer 36

> 0.06

Question 37

large partial η^2

Answer 37

> 0.14

Question 38

partial η^2 formula

Answer 38

Question 39

Cohen’s d formula

Answer 39

do it separately for each combination of IV levels

Question 40

note

Answer 40

practice calculating partial eta squared by hand might be checked in a quiz