EBP2 NonParametric Testing and Chi Square Flashcards
What type of data is used in nonparametric testing?
nominal or ordinal
What are non-parametric statistics based on?
comparisons of ranks of scores
or
comparisons of counts (yes/no) or “signs” of scores
True/False: Nonparametric tests are less powerful compared to parametric statistics.
true (~65-95% of parametric equivalent)
Match the nonparametric test to the comparison:
Two independent groups
Unpaired T-test
Mann-Whitney U test
Match the nonparametric test to the comparison:
Two related scores
paired t-test
Sign test
Wilcoxon signed-ranks test
Match the nonparametric test to the comparison:
Three or more independent groups
one-way ANOVA
Kruskal-Wallis analysis of variance by ranks
Match the nonparametric test to the comparison:
Three or more related scores
One-way repeated measures ANOVA
Friedman two-way analysis of variance by ranks
Match the nonparametric test to the comparison:
2x3 mixed ANOVA
NONE
unable to perform on more complex designs
What type of test is used based on ranks (equivalent to independent t-test)?
Mann-Whitney U
What type of test is used based on signs (equivalent to paired t-test)?
Sign test/Wilcoxon signed-ranks test
What is the question to ask regarding rank tests?
Is the difference in ranks larger than would be expected by chance alone?
What is the question to ask regarding signs tests?
Is the difference in sign frequencies larger would be expected by chance alone?
What type of test looks for association between nominal variables?
chi-square
What are the two types of chi-square?
goodness of fit and tests of independence (association)
Describe goodness of fit test.
compare observed frequencies of 1 variable to uniform of another
Describe tests of independence (association).
compare observed frequencies from 1 variable to observed frequencies of another variable
What is the question to ask during chi-square?
is the difference between expected and observed frequencies larger than would be expected by chance alone?
You are looking at baseline demographics between two groups in a table published in an article. You note a p-value of .87 (alpha set at .05) for the characteristic of gender. Which test was most appropriately used to compare genders between groups at baseline?
chi-squared
You are wanting to compare two groups in a study you are designing. One group is getting eccentric exercises targeting the gluteus medius muscle group and the other group is getting concentric exercises targeting the same muscle group. Subjects were randomly selected from 3 different clinics located at different geographical locations. The outcome of interest is muscle strength which will be measured as either “strong”, “diminished” or “poor” via a manual muscle testing procedure. Which is most appropriate in this situation?
Mann-Whitney U
You are wanting to compare four different groups in a study you are designing for individuals with persistent low back pain. One group is getting mirror box training, another group is getting laterality training, the third group is getting a combination of both and the final group is the control group. The outcome of interest is tolerance to pressure at the L4 segment and measured as “hypersensitive”, “normal” or “diminished”. The data will be collected prior to the intervention and then 4 weeks post intervention. The group is randomly selected from several clinics. Which is most appropriate in this situation?
Kruskal-Wallis
When is a Fisher’s exact test used instead of a Chi square?
small samples
You are performing a research trial looking at strength training in those with ACL-deficient knees. You are only able to recruit 10 subjects from 1 clinic that sees collegiate soccer players on a school campus. You will be comparing two groups (experimental and control) and look at strength via a Biodex machine (Newtons) over 3 time intervals. Which test is most appropriate?
a. two way ANOVA
b. 2x3 mixed-model ANOVA
c. Wilcoxon signed-ranks test
d. none of the above
none of the above
because it would be a 2x3 mixed but due to the non-parametric qualities cannot do
