Oneway ANOVA Defined Flashcards
ANOVA stands for?
Analysis of variance
Oneway ANOVA?
Only 1 grouping variable
- 1 categorical group w/ 3 or more variables and 1 continuous group
- only 1 independent variable
What is ANOVA used for?
3 ir more groups to test for mean differences Ex: caffeine study w/ 3 groups -no caffeine -mild dose -high dose
What’s the null hypothesis?
All pops. are equal to each other
-mew 1= mew 2= mew 3
What is the f statistic?
Measures the difference between groups/ difference within groups
- it tells if the means are different
- if significant, it means the means or averages are not the same
Hiw many differences for the ANOVA to be significant?
1
We usually refer to sub populations as what in ANOVA?
Groups
What does ANOVA do?
The means of all the groups are equal
What does it mean to reject the null hypothesis?
There’s a difference between the two means; a definte relationship
What is the grand mean?
The mean of all the data in a chart
What is a post Hoc test?
If you have a significant ANOVA and you wanna see where the significance is
-means “after this” in Latin
Ex: Nia had a test she wanted to run in the lab but needed an ANOVA test to do so. Her ANOVA results were significantly different so she had a post Hoc test to find the significance
What does it mean to fail to reject the null hypothesis?
The two means are the same
Ex: Kendall figured out that the means of the two groups were the same so she had to fail to reject the null hypothesis
A large value of F indicates what?
relatively more difference between groups than w/in groups
How to find the degrees of freedom between/numerator (groups)?
# of groups-1 Ex: 3 groups; df=3-1=2 df=2 Ex: 7 groups; df=7-1=6 df=6
How to find the degrees of freedom within/denominator (sample size)?
N-1-k, where k is df between Ex: N=500; 3 groups 500-1-(3-1)=497 Ex: N=45; 4 groups 45-1-(4-1)=41
