Sampling & Probability
The distribution of sample means I would get if I took all possible samples of size n from a population is called…
Sampling distribution
What is the first step of hypothesis testing?
Which steps are different between two-tailed and one-tailed tests?
Steps 1 and 2 (state hypotheses and define critical value)
The variable in an experiment that is measured is…
Independent variable
What kind of hypothesis (null vs. alternative and 1 vs 2 tailed) is the following?
µtest score = 15
Null hypothesis, two tailed
The “spread” of a sampling distribution is called…
Mean standard error
If my z critical is +/-1.96 and I find a z value of 2.35 for my sample, what decision should I make?
Reject the null/accept the alternative
How do I find the critical value of z given alpha of .05 with a two-tailed test?
Look for value of .025 in column C and select z value
Any variable that is not one of the variables being manipulated or measures is…
An extraneous variable
You design a study investigating the effects of screen time on sleep. You manipulate hours of screen time using an app and measure hours slept per day for a week. Participant diet is...
An extraneous variable
If I draw a sample of 16 people from a population with a mean of 50 and a standard deviation of 10, what is my expected sample mean?
50
If I am only interested in evaluating the benefits of an intervention, what kind of test should I use?
One-tailed
What does effect size tell us that hypothesis testing does not?
The meaningfulness or magnitude of the effect, unaffected by sample size
Under what circumstance does an extraneous variable become confounding?
It varies systematically with the independent variable
What strategy is used to control for order effects in a within-subjects design?
Counterbalancing
As population variance increases, what happens to standard error?
Increases
What does my critical value for z represent?
The value that sets the threshold for what is considered “extreme”
If a drug is effective, but the researcher fails to find evidence of its effectiveness, what kind of error have they committed?
Type II
Counterbalancing is important to control for order effects in what kind of design?
Within-subjects
An unethical practice in hypothesis testing that raises your risk for a Type I error is called...
P-hacking (examples: multiple comparisons, cherry picking, data snooping)
If a population distribution is positively skewed, the sampling distribution with sample sizes of 100 will be what shape?
Normal distribution
If I fail to reject the null, how do I interpret my finding?
Finding is inconclusive, failed to find evidence for the alternative but NOT evidence FOR the null hypothesis
The probability that a test will correctly detect a real effect (and correctly reject the null) is…
Power/Statistical power
Critiques about potential confounding variables are related to the experiment’s…
Internal validity
A critique of a study's sample size would be a critique of what kind of validity?
Statistical validity