Statistics Final Exam Questions With Correct Solutions.
When do you use an ANOVA? - accurate answers-When you want to compare
two or more means
What does ANOVA protect researchers from? - accurate answers-Making a
Type I Error
What is a Factor? - accurate answers-The variable that designates the groups
being compared (IV)
What are Levels? - accurate answers-Individual conditions or vales that make
up a factor
Hypotheses for ANOVA - accurate answers-Ho: u₁ = u₂ = u₃
H₁: There is at lease one mean difference among the populations
T/F: ANOVAs tell us that differences exist, but not what those differences are -
accurate answers-True
Assumptions of the ANOVA - accurate answers-1. The observations w/i each
sample are independent
2. Population from which samples are selected from are normal
3. Populations from which samples are selected from have equal variance
(homogeneity)
T/F: For ANOVAs, you want equal sized n's to have equal randomness -
accurate answers-True
When do you compute post-hoc analyses? - accurate answers-When the
ANOVA is significant
What does a post-hoc do in an ANOVA? - accurate answers-tells you specific
significant differences in each sample
Benefit of Bonferonni vs. Tukey's - accurate answers-Bonferonni is more
conservative
What is an F-Ratio? - accurate answers-A ratio between two sample variances
, Numerator of the F-Ratio for an ANOVA - accurate answers-MSbetween
What does MSbetween measure? - accurate answers-the size of mean
differences between samples
What does MSwithin measure? - accurate answers-the size of mean
differences within samples; estimates the expected variance by chance
Denominator of the F-Ratio for an ANOVA - accurate answers-MSwithin
difference between independent-measures t-test and ANOVA - accurate
answers-ANOVA based on variance, t-test based on sample mean difference
Which of the following is the correct description for a research study
comparing problem-solving scores obtained for 3 different age groups of
children? - accurate answers-Three-level design
A study is comparing people who live in urban centers vs. suburbs vs. rural
areas on willingness to seek psychological care. What test do you need to run?
- accurate answers-ANOVA
For t-test and ANOVA, high/low within group variance and high/low between
group variance is most likely to produce a significant outcome of a research
study - accurate answers-low; high
What is the repeated-measures ANOVA? - accurate answers-compares two or
more treatment conditions with the same subjects tested in all conditions
2 advantages to repeated measures design - accurate answers-1. individual
differences among participants do not influence outcomes
2. smaller number of subjects needed to test all treatments
What is different about the RM ANOVA? - accurate answers-includes a second
analysis in which variability due to individual differences is subtracted from
the error term
Numerator of F-Ratio for repeated measures ANOVA - accurate answers-
treatment effect + random, unsystematic differences
When do you use an ANOVA? - accurate answers-When you want to compare
two or more means
What does ANOVA protect researchers from? - accurate answers-Making a
Type I Error
What is a Factor? - accurate answers-The variable that designates the groups
being compared (IV)
What are Levels? - accurate answers-Individual conditions or vales that make
up a factor
Hypotheses for ANOVA - accurate answers-Ho: u₁ = u₂ = u₃
H₁: There is at lease one mean difference among the populations
T/F: ANOVAs tell us that differences exist, but not what those differences are -
accurate answers-True
Assumptions of the ANOVA - accurate answers-1. The observations w/i each
sample are independent
2. Population from which samples are selected from are normal
3. Populations from which samples are selected from have equal variance
(homogeneity)
T/F: For ANOVAs, you want equal sized n's to have equal randomness -
accurate answers-True
When do you compute post-hoc analyses? - accurate answers-When the
ANOVA is significant
What does a post-hoc do in an ANOVA? - accurate answers-tells you specific
significant differences in each sample
Benefit of Bonferonni vs. Tukey's - accurate answers-Bonferonni is more
conservative
What is an F-Ratio? - accurate answers-A ratio between two sample variances
, Numerator of the F-Ratio for an ANOVA - accurate answers-MSbetween
What does MSbetween measure? - accurate answers-the size of mean
differences between samples
What does MSwithin measure? - accurate answers-the size of mean
differences within samples; estimates the expected variance by chance
Denominator of the F-Ratio for an ANOVA - accurate answers-MSwithin
difference between independent-measures t-test and ANOVA - accurate
answers-ANOVA based on variance, t-test based on sample mean difference
Which of the following is the correct description for a research study
comparing problem-solving scores obtained for 3 different age groups of
children? - accurate answers-Three-level design
A study is comparing people who live in urban centers vs. suburbs vs. rural
areas on willingness to seek psychological care. What test do you need to run?
- accurate answers-ANOVA
For t-test and ANOVA, high/low within group variance and high/low between
group variance is most likely to produce a significant outcome of a research
study - accurate answers-low; high
What is the repeated-measures ANOVA? - accurate answers-compares two or
more treatment conditions with the same subjects tested in all conditions
2 advantages to repeated measures design - accurate answers-1. individual
differences among participants do not influence outcomes
2. smaller number of subjects needed to test all treatments
What is different about the RM ANOVA? - accurate answers-includes a second
analysis in which variability due to individual differences is subtracted from
the error term
Numerator of F-Ratio for repeated measures ANOVA - accurate answers-
treatment effect + random, unsystematic differences
