Exam II Flashcards
(84 cards)
What is ANOVA used for?
To study grouping variables that are not dichotomous.
Give an example of a grouping variable suitable for ANOVA.
Grade level, injury type, decade of life, or >2 treatment groups.
What is one strategy for comparing multiple groups?
Conduct t-tests between each pair of groups.
What is the problem with conducting multiple t-tests?
It increases the likelihood of a Type I Error.
What happens as the number of comparisons increases?
The greater the error rate.
True or False: ANOVA is only applicable for dichotomous grouping variables.
False.
Fill in the blank: ANOVA is often used when studying grouping variables that are _______.
not dichotomous.
What type of test is ANOVA classified as?
Omnibus test
An omnibus test assesses whether there are any statistically significant differences among the means of three or more independent groups.
What is a key characteristic of ANOVA?
General, not specific
ANOVA does not indicate which specific groups are different, only that at least one group differs.
What is a common phrase associated with ANOVA to describe its function?
One of these things is not like the others
This phrase highlights the goal of ANOVA to identify differences among group means.
What defines the three or more groups being compared?
Grouping Variable
What is another term often used for a Grouping Variable?
Factor
Is the Grouping Variable usually an independent variable?
Yes
What is a Measurement/Outcome Variable?
A variable that is usually the dependent variable in a study.
What types of scales can a Measurement/Outcome Variable be?
Interval, ratio, or ordinal.
What does One-Way ANOVA compare?
The means of three or more independent groups defined by one factor (grouping variable)
One-Way ANOVA is used to determine if there are statistically significant differences between the means of the groups.
Is One-Way ANOVA a parametric or non-parametric test?
Parametric test
It assumes a normal distribution of the data.
What assumption does One-Way ANOVA make about the groups?
Homogeneity of variance between the groups
This means that the variance among the groups should be approximately equal.
What statistics should reports of One-Way ANOVA include?
Mean and SD for each group, F-statistic, numerator df, denominator df, p-value, and effect size
These statistics help in interpreting the ANOVA results.
What does ANOVA compare to determine if group means are different?
Within and between group variance
ANOVA assesses how much variation exists within each group and how much variation exists between different groups.
True or False: ANOVA can only compare two groups.
False
ANOVA is designed to compare means across three or more groups.
What is the primary purpose of ANOVA?
To determine if the means of the groups are different from one another
ANOVA helps to identify whether observed differences in sample means are statistically significant.
What tests are conducted to determine which group(s) are different from which other(s) after ANOVA?
Post-hoc or ‘follow-up’ tests
What action is taken if the computed f-ratio is greater than 2.70?
Reject the null hypothesis
This decision is based on the comparison of the computed f-statistic with the critical value. If your computed F-ratio is greater than the critical F-value, you reject the null hypothesis (H₀), meaning there is a statistically significant difference between group means.