Biostatistics Final Exam Definitions UTA
Questions And Answers
Bonferroni-Holm Multiple Comparisons -
correct answer ✅-In the context of an ANOVA, rejecting the null
hypothesis means there is a statistical difference between at least
two means, but it won't tell you where it is. You use this to discover
exactly which means are different.
-Only used for Model I ANOVAs
-A t-statistic for a two sample t-test assuming equal variance
Steps to Applying the Bonferroni-Holm Multiple Comparison Test -
correct answer ✅Step 1: Calculate test statistics and
corresponding P values for each of the m comparisons
Step 2: Order the P values from smallest to largest: p1,p2,...,pm.
Label the corresponding comparisons: C1,C2,...Cm
Step 3: Compare p1 and alpha(a)/m
(a) If p1 > a/m, then stop. Conclude that there is no evidence of
differences between any of the means. Procedure is done
(b) p1 < or = a/m, then reject Ho for C1. Continue to next step.
,Biostatistics Final Exam Definitions UTA
Questions And Answers
Step 4: Compare p2 and a/(m-1)
(a) If p2 > a/(m-1), then stop. There is no evidence of differences
between any of the means in the remaining comparisons.
Procedure is done.
(b) p2 < or = a/(m-1), then reject Ho for C2. Continue to next step.
Step 5: Compare p3 and a/(m-2)
(a) If p3 > a/(m-2), then stop. There is no evidence of differences
between any of the means in the remaining comparisons.
Procedure is done.
(b) p3 < or = a/(m-2), then reject Ho for C3. Continue to next step
Continue until procedure requires you to stop or until all P values
have been compared
Kruskal-Wallis Test -
correct answer ✅The nonparametric analog to a Model I One-Way
ANOVA. We would use if it we reject the assumption of normality
for the data.
, Biostatistics Final Exam Definitions UTA
Questions And Answers
Randomized-Complete Block Design ANOVA -
correct answer ✅Used to extend paired experimental designs to
accommodate making more than just two measurements on the
same individuals. Also called Repeated Measures ANOVA.
Model Assumptions:
1. Each observation constitutes a random, independent sample
from a population with mean u_ij. There are k x b of these
populations sampled.
2. Each of the k x b populations is normal and with the same
variance.
3. The treatment and block effects are additive, that is, there is no
interaction (synergy or interference) between blocks and
treatments.
Factorial-Design Two-Way ANOVA -
correct answer ✅Model Assumptions:
1. The observations in each cell constitute an independent random
sample of size n from a population with mean u_ij
2. Each of the population represented by the cell samples is normal
and has the same variance.
Questions And Answers
Bonferroni-Holm Multiple Comparisons -
correct answer ✅-In the context of an ANOVA, rejecting the null
hypothesis means there is a statistical difference between at least
two means, but it won't tell you where it is. You use this to discover
exactly which means are different.
-Only used for Model I ANOVAs
-A t-statistic for a two sample t-test assuming equal variance
Steps to Applying the Bonferroni-Holm Multiple Comparison Test -
correct answer ✅Step 1: Calculate test statistics and
corresponding P values for each of the m comparisons
Step 2: Order the P values from smallest to largest: p1,p2,...,pm.
Label the corresponding comparisons: C1,C2,...Cm
Step 3: Compare p1 and alpha(a)/m
(a) If p1 > a/m, then stop. Conclude that there is no evidence of
differences between any of the means. Procedure is done
(b) p1 < or = a/m, then reject Ho for C1. Continue to next step.
,Biostatistics Final Exam Definitions UTA
Questions And Answers
Step 4: Compare p2 and a/(m-1)
(a) If p2 > a/(m-1), then stop. There is no evidence of differences
between any of the means in the remaining comparisons.
Procedure is done.
(b) p2 < or = a/(m-1), then reject Ho for C2. Continue to next step.
Step 5: Compare p3 and a/(m-2)
(a) If p3 > a/(m-2), then stop. There is no evidence of differences
between any of the means in the remaining comparisons.
Procedure is done.
(b) p3 < or = a/(m-2), then reject Ho for C3. Continue to next step
Continue until procedure requires you to stop or until all P values
have been compared
Kruskal-Wallis Test -
correct answer ✅The nonparametric analog to a Model I One-Way
ANOVA. We would use if it we reject the assumption of normality
for the data.
, Biostatistics Final Exam Definitions UTA
Questions And Answers
Randomized-Complete Block Design ANOVA -
correct answer ✅Used to extend paired experimental designs to
accommodate making more than just two measurements on the
same individuals. Also called Repeated Measures ANOVA.
Model Assumptions:
1. Each observation constitutes a random, independent sample
from a population with mean u_ij. There are k x b of these
populations sampled.
2. Each of the k x b populations is normal and with the same
variance.
3. The treatment and block effects are additive, that is, there is no
interaction (synergy or interference) between blocks and
treatments.
Factorial-Design Two-Way ANOVA -
correct answer ✅Model Assumptions:
1. The observations in each cell constitute an independent random
sample of size n from a population with mean u_ij
2. Each of the population represented by the cell samples is normal
and has the same variance.
