Week 4

Question 1

Error in statistical models…

a.
Is typically ignored
b.
Is important to measure, report and interpret
c.
Is only apparent on rare occasions
d.
Purely reflects measurement error

Answer 1

b.
Is important to measure, report and interpret

Question 2

What three factors affect statistical power?
a.
Sample size, effect size, type 1 error rate
b.
Sample size, statistical significance, type 1 error rate
c.
Sample size, effect size, independence
d.
Sample size, statistical significance, independence

Answer 2

a.
Sample size, effect size, type 1 error rate

Question 3

Data = x + y, where x and y are…
a.
Variance and error
b.
Model and error
c.
Distribution and model
d.
Variance and distribution

Answer 3

b.
Model and error

Question 4

What is not a step in Null Hypothesis Testing?

a.
Formulate an interpretation of the data before analysis
b.
Formulate a hypothesis that embodies our prediction
c.
Assess the “statistical significance” (p value) of the result
d.
Collect some data relevant to the hypothesis

Answer 4

a.
Formulate an interpretation of the data before analysis

Question 5

The probability (p) value is…

a.
The probably that if you ran the study again, you would obtain the same result that % of the time
b.
The probability that you are making the wrong decision
c.
The probability of the null hypothesis being true
d.
Under the assumption that the null hypothesis is true, the probability of getting a sample as or more extreme as our own

Answer 5

d.
Under the assumption that the null hypothesis is true, the probability of getting a sample as or more extreme as our own

Question 6

Statistical significance is not…
a.
Determined by comparing the p value with the alpha value
b.
A measure of effect size
c.
A dichotomous assessment
d.
Based on a relatively arbitrary cut-off point

Answer 6

b.
A measure of effect size

Question 7

What is an appropriate way to report a statistical model?

a.
There was a trend for significance
b.
The effect was statistically significant
c.
The effect was nearly significant
d.
The effect approached significance

Answer 7

b.
The effect was statistically significant

Question 8

The alpha value is…
a.
A alternative measure of effect size
b.
Set before analyses are run
c.
Akin to the p value
d.
Always 0.05

Answer 8

b.
Set before analyses are run

Question 9

Type 1 errors reflect x, and type 2 errors reflect y. What are x and y, respectively?
a.
False positives and false negatives
b.
They both reflect false positives
c.
False negatives and false positives
d.
They both reflect false negatives

Answer 9

a.
False positives and false negatives

Question 10

Effect size is a measure of…
a.
The significance of the effect
b.
The error of the effect
c.
The variability of the effect
d.
The strength of the effect

Answer 10

d.
The strength of the effect