PARAMETRIC Pt.2 Flashcards
Used to test claims involving three or more means
ANOVA
More superior compared to T-Test
ANOVA
ANOVA
ONE-WAY ANALYSIS OF VARIANCE
Advantages of using ANOVA compared to T-Test: When you are comparing two means at a time, the rest of the means under study are ignored. With the _____, all the means are compared simultaneously.
F test
Advantages of using ANOVA compared to T-Test: When you are comparing two means at a time and making all pairwise comparisons, the probability of rejecting the null hypothesis when it is true is ________, since the more t tests that are conducted, the greater is the likelihood of getting significant differences by chance alone.
increased
Advantages of using ANOVA compared to T-Test: The more means there are to compare, the more ______ are needed.
t-tests
when an F-test is used to test a hypothesis concerning the means of 3 or more populations
Analysis of Variance
sample sizes need not to be equal
Analysis of Variance
2 ESTIMATES OF ANOVA
Between-group Variance
Within-group Variance
finding variance of the means
Between-group Variance
finding the variance for all data
Within-group Variance
If there is no difference in the means, the between-group variance estimate will be approximately equal to the within-group variance estimate, and the F-test value will be approximately equal to _____. The null hypothesis will not be rejected.
one
when the means differ significantly, the between-group variance will be much _______ than the within-group variance; the F-test value will be significantly greater than one; and the null hypothesis will be ________.
larger/ rejected
The degrees of freedom for this F-test is (Numerator)
d.f.N = _______, where k is the number of groups
k – 1
(Denominator) d.f.D = ______, where N is the sum of the sample sizes of the groups
N – k
ANOVA: ______ is always positive and always right-tailed
F-Test
PERFORMING POST-HOC TESTS
→ Comes from the Latin word, meaning
“after this”
Commonly used tests to locate where the significant differences in the means lie after the ANOVA procedure has been performed
POST-HOC TESTS
2 TYPES OF POST-HOC TESTS
- Scheffe or Scheffe’s Test
- Tukey Test or Tukey HSD
When null hypothesis has been rejected, ________ is performed to determine which of the means have a significant difference
Post-Hoc
POST HOC:
- can be used when samples are of different sizes
- can be used to make pairwise comparisons (sample 1 + sample 2 VS sample 3)
Scheffe Test
POST HOC:
- when samples are equal in size
- narrower confidence limit
- more powerful than the Scheffe test for making pairwise comparisons for the mean
Tukey
WHAT TYPE OF ANOVA MUST BE USED?
Independent: − Soil type
Dependent: − Plant growth
ONE-WAY ANOVA
WHAT TYPE OF ANOVA MUST BE USED?
Independent: − Soil type − Plant food
Dependent: − Plant growth
TWO-WAY ANOVA
