General linear model and ANOVA Flashcards
1
Q
what is the general linear model?
A
- Framework for comparing how several variables affect different continuous variables
2
Q
what does general linear model include?
A
- correlations
- t- tests
- regression
- ANOVA/ ANCOVA
3
Q
why does general linear model work?
A
- because it assumes that the residuals will be normally distributed and that different statistical tests combine linearly
4
Q
why is it known as linear?
A
- because different stats tests add together in a simple way
5
Q
what are the two main purposes of the general linear model?
A
- strengths and directions of relationships and differences
- strengths of interactions and manipulations
6
Q
what do all general linear model tests analyse?
A
- all analyse variance
7
Q
what differences do ANOVAs find?
A
- categorical differences between different conditions or different groups in a study
8
Q
what are the two special kinds of linear regression?
A
- ANOVA
- T test
9
Q
what is regression?
A
- statistical test to analyse relationship between a dependent variable (target) and one or more independent variables ( predictor)
10
Q
what does ANOVA test?
A
- tests differences between two or more means
11
Q
how is ANOVA different from a t-test?
A
- t- test generally used for comparing two means whereas ANOVA used for three
12
Q
describe the variables of an ANOVA test
A
one categorical predictor (group= IV)
+
one continuous outcome (measure= DV)
13
Q
what is a one way ANOVA?
A
- compares the means of three or more independent groups to determine if there is a statically significant difference between the means
14
Q
how many groups in one- way ANOVA?
A
- three or more groups
15
Q
how many variables, predictors and outcomes in one way ANOVA?
A
- one outcome variable
- one categorical predictor
- one continuous outcome
16
Q
what is factorial (or multi- way) ANOVA?
A
- used when you’d like to understand how two or more factors affect a response variable and whether or not there is an interaction effect between the factors and the response variable
17
Q
how many groups in factorial ANOVA?
A
- two or more groups
18
Q
how many variables, predictors and outcomes in factorial ANOVA?
A
- two or more categorical predictor variables (sex, group)
- one continuous outcome variable(measure)
19
Q
what is the grid created in factorial ANOVA? can individuals be in more than one group?
A
- 2 x 2
- four individual groups
- each person can only be in one
20
Q
what is repeated measures ANOVA also known as?
A
- within- subjects
21
Q
what is repeated measures ANOVA?
A
- compares means of three or more groups in which the same subjects show up in each group
22
Q
how many groups in repeated measures ANOVA?
A
- one group
23
Q
how many predictors and outcomes in repeated measures ANOVA?
A
- two or more categorical predictors
- one outcome variable (measure)
24
Q
what is mixed ANOVA?
A
- compares mean differences between groups based on two factors : within and between subjects
25
how many groups in mixed ANOVA?
- two or more groups
26
how many predictors and outcomes in mixed ANOVA?
- one or more categorical predictors
- one outcome variable
27
what are the three things you should work out before deciding the appropriate test?
- between group variable
- within group variable
- levels of variable
28
what does the graph need to have? and why?
- needs to have error bars
- to show significance
- how big is the difference relative to the size of error
29
what does a small standard deviation mean?
- low spread
- data around mean
30
what are the four other different types of test?
- MANOVA
- ANCOVA
- logistic regression
- multivariate regression
31
what is MANOVA?
- used for multiple outcome variables
e.g., height and weight
32
what is ANCOVA?
- used for continuous predictor variable
e.g., cholesterol
33
what is logistic regression?
- discrete outcome variances
e.g., diabetes/ not
34
what is multivariate regression?
- multiple predictor and outcome variables
e.g., cholesterol, height, diabetes/ not, weight
35
how do you use one way ANOVA on jamovi?
- select one way ANOVA
- chose mean difference and report significance
36
what type of ANOVA isn't on jamovi, what do you pick instead?
- Factorial ANOVA isn't on jamovi
- just 'ANOVA'
37
what is mixed ANOVA under on jamovi?
- under repeated measures
38
how do you report one way ANOVA results?
F (df1, df2), p value
39
how do you find df1?
number of groups - 1
40
how do you find df2?
number of values- number of groups
41
what do you run after finding a significant difference among three or more groups/ conditions? what are they?
- run post- hoc tests to see which groups were significantly different from each other
- they are t- tests but with some corrections applied to the p- values
42
what corrections are applied to post- hoc tests?
- corrections consider multiple comparisons
43
what is interaction ?
- between two variables
- differences in one variable are affected by differences in another variable
44
what does the interaction speciality depend on?
- your theory
- how you entered the data into ANOVA
45
how are interactions indicated?
- by a star *
46
what is sphericity?
- variances of the differences between all combinations of related groups (levels) are equal
47
does all data need to be corrected?
- no correction if variability is similar for the conditions
48
what is non- sphericity?
- variances of the differences between all combinations are not equal
49
what changes when you report results after correction?
- degrees of freedom changes
50
what is the assumptions about observations in ANOVA?
- observations are independent e.g., from different people; different times
51
what is the assumption about variance in ANOVA?
- variance of different groups or conditions should be equal
52
what is the assumption about residuals in ANOVA?
- residuals will be normally distributed
53
what are residuals?
- unexplained variance/ error
54
what is the assumption in repeated measures ANOVA?
- differences between levels of a variable should have equal vairance
55
if you have three or more groups/ conditions in a variable in a RM ANOVA what should you check?
- check sphericity
