GW08 Hypothesis testing & power: study guide
NOTE 1: include each question with its corresponding answer!
NOTE 2: paraphrase explanations from the text - don't merely copy
verbatim.
1 Define: Hypothesis testing.
2
Identify, define, and note an example of the two hypotheses used in hypothesis
testing.
3 Explain how the distribution of sample means is divided when evaluating
hypotheses.
Include a sketch that depicts the division.
4 Define and explain alpha level and critical region.
Include a sketch that depicts the critical
region.
5
What are the two possible decisions regarding the viability of the null
hypothesis?
6 Explain why we test the null hypothesis rather than the alternative
hypothesis.
7 Explain the z-score formula in words regarding the actual
difference between the sample mean & the
pop mean versus the expected
difference between them. Then explain what we mean by a "test
statistic," and the z-score's
use as a general model (a ratio) for most test statistics (GW 235 - 236).
[Note: don't simply copy the
text's wording, since copying is NOT the same as explaining.
Paraphrasing is, of course,
certainly O.K.]
8 We are now entering fully into the "inferential statistics" section of
the course. Explain why we call it
"inferential."
9 Identify, explain, and provide an example of each of the two types
of errors that are possible in
hypothesis testing. [Be able to sketch, label, and explain the
"possible outcomes" decision matrix
illustrated on page 239 of GW.]
10
Explain how alpha level is related to decision errors in hypothesis testing.
11
Explain the relations between different values of alpha and rejecting Ho (i.e., demonstrating a treatment
effect or group
differences). Include a sketch.
12
Explain statistical significance.
13 Identify and explain the three factors than influence a hypothesis test.
14
Name and explain the four assumptions that must be made in order to use z-scores
in hypothesis testing.
15 Explain and compare & contrast one-tailed and two-tailed hypothesis tests;
note when each is used, and
provide a
real-world example of each [make up an example that is not in the text].
16 One of the concerns that scientists often express regarding hypothesis
testing is based on "treatment
effect" issues. Explain those issues & note
how they can be addressed in a research report via "effect
size."
17 In correlation and regression we usually report r2 as our
measure of effect size. Note which measure of
effect size we use for z-tests
and briefly explain how it works.
18 Define power.
20
List and explain the four factors affecting power.