Internal Validity
Statistical Tests
Multiple Choice
Miscellaneous
More Misc. :)
100
Name the threat to internal validity in the following scenario: Participants perform better or more similarly because they have already completed the task
Practice Effects
100
In general, _______ tests are more powerful than _______ tests.
Parametric, nonparametric
100
Three of the many factors that can affect the statistical power of a study are:
a. Delta, sample size, & equality of group sizes
b. Effect size, type of test used, & gamma level
c. Sample size, alpha level, & effect size
d. Number of levels of the IV, alpha level, & randomness of the sample
c. Sample size, alpha level, & effect size
100
The term ___________ refers to the fact that you must add the alpha levels across multiple related t-tests, which increases the type I error rate across the family of tests.
Family-wise alpha level
100
Compared to quasi-experiments, true experiments always have:
Random assignment to conditions
200
Name the threat to internal validity in the following scenario: Participants in different groups talk to each other and mess up the manipulation of IV.
Treatment contamination
200
The result of an independent samples t-test comparing Group A ( = 75) and Group B (
= 70) is, t(30) = 2.50, p > .05. What can you conclude?
There is no mean difference between the groups.
200
Researchers use _______ to handle order or practice effects.
a. Counterbalancing
b. Control groups
c. More interesting stimuli
d. Unobtrusive observations
a. Counterbalancing
200
When statisticians are predicting an unknown value (Y) from a known value (X) when the two variables are correlated, it is called:
Regression
200
The __________ hypothesis states that there is no real difference between the sample means and the _______ states that there is a real difference between the sample means.
Null; alternative
300
Name the threat to internal validity in the following scenario: Participants choose the condition or are not randomly assigned to groups.
Self-selection bias
300
What statistical test tells us whether frequency counts for two nominal/ordinal variables are related?
Chi Square Test of Independence
300
The average difference between the actual Y values from those predicted by the regression line Y’ is:
a. Standard error of the mean
b. Coefficient of determination
c. Standard error of estimate
d. Standard variance estimate
c. Standard error of estimate
300
Name three factors that can affect the statistical power of a study.
Sample size, alpha level, effect size, directionality of hypotheses (Two or one tailed), Study design (Between vs. within groups design), relative sample sizes of the IV groups, inferential statistical test choice, precision of the study variables
300
A _________ distribution is flatter than the normal distribution (i.e., has more extreme scores) while a _________ distribution is more peaked than the normal distribution (i.e., has fewer extreme scores).
Platykurtic; leptokurtic
400
Name the threat to internal validity in the following scenario: Overt or subtle cues to participants on how to react.
Demand characteristics
400
What is the difference between an independent samples t test and paired samples t tests?
Independent sample t-test: Use when you want to compare the mean of one sample (x̄1) to the mean of another sample (x̄2)
Paired sample t-test: Use when the two groups of scores are related to one another (not independent of each other)
400
Failing to reject the null hypothesis when it is actually false is called a _____ error, and rejecting the null when the null hypothesis is true is called a _______ error.
a. Type II; Type I
b. Type I; Type II
c. Type I; Type III
d. Type III; Type II
a. Type II; Type I
400
Regression to the mean effects are controlled by using _____; and demand characteristics are controlled by using ______.
Control groups; double blind research
400
The average difference between the actual Y values from those predicted by the regression line Y’ is:
Standard error of estimate
500
What is the difference between mortality and differential mortality?
Mortality: Loss of participants due to refusal to continue, relocation, and death, disinterest, etc.
Differential Mortality: In a study with two or more groups, when participants in one group drop out more than those in another condition.
500
Three of the statistical assumptions for the paired-samples t test are:
Homogeneity of variances, dependence, & normality
500
Given the following information, determine whether or not an error in the statistical decision has been made. If so, state the type of error:
· H0: 𝑋̅1 = 𝑋̅2
· 𝑎 = .05
· obtained sig value: .08
· actual status of H0: True
a. No Error
b. Type I error
c. Type II error
d. Type I & Type II error
a. No Error
500
Given the following information, determine whether or not an error has been made in statistical determination. If so, state the type of error.
- H0: X1 = X2
- p = .01
- obtained sig value: .002
- actual status of H0: True
Type 1 Error
500
Failing to reject the null hypothesis when it is actually false is called a _____ error, and rejecting the null when the null hypothesis is true is called a _______ error.
Type II, Type I