Key terms for chapters 8 – 13
Chapter 8 difference or relationship (EXACT
OPPOSITE FROM NULL)
Hypothesis test: a stat method that uses
Has effect on the DV
sample data to evaluate a hypothesis about a
Alpha Level or the Level of Significance:
population probability value that is used to define the
Including assumptions and steps
concept of “very unlikely” in a hypothesis
1. State the null hypothesis and
test
select an alpha level. Also
Critical Region: composed of the extreme
state an alternative
sample values that are very unlikely (defined
hypothesis.
by alpha level) to be obtained if null is true
2. Locate the critical region.
Boundaries are determined by the
3. Collect the data and compute
alpha level
the test statistic. (sample
Type I Error: occurs when a researcher
mean transformed into a z-
rejects a null hypothesis that is ACTUALLY
score)
TRUE
Type II Error: occurs when a researcher
fails to reject a null hypothesis that is
REALLY FALSE
Significant or Statistically Significant:
when a result is VERY UNLIKELY to occur
when the null hypothesis is true
Factors that affect significance
4. Make a decision based on if Beta: the probability of a type II error that
the z-score is in the critical cannot be specified as a single value and
region or not. depends in part on the size of the treatment
If it is in critical effect
region, reject H0 and Directional tests:
conclude that the One-tailed: the statistical hypothesis (H0
treatment has changed and H1) specify either an increase or
the pop. mean. decrease in the population mean
If it isn’t in the Make a statement about the direction
critical region, fail to of the effect
reject H0 because the Two-tailed tests:
data are not Effect size: intended to provide a
significantly different measurement of the absolute magnitude of a
from the null. treatment effect, independent of side of
Null hypothesis: states that in general sample(s) being used
population, there is no change, difference or Factors that affect effect size
relationship (EXACT OPPOSITE FROM Cohen’s d: one of the simplest and direct
ALT.) methods of measuring effect size
Has no effect on the DV
Alternative hypothesis: states that in
general population, there IS change,
Chapter 8 difference or relationship (EXACT
OPPOSITE FROM NULL)
Hypothesis test: a stat method that uses
Has effect on the DV
sample data to evaluate a hypothesis about a
Alpha Level or the Level of Significance:
population probability value that is used to define the
Including assumptions and steps
concept of “very unlikely” in a hypothesis
1. State the null hypothesis and
test
select an alpha level. Also
Critical Region: composed of the extreme
state an alternative
sample values that are very unlikely (defined
hypothesis.
by alpha level) to be obtained if null is true
2. Locate the critical region.
Boundaries are determined by the
3. Collect the data and compute
alpha level
the test statistic. (sample
Type I Error: occurs when a researcher
mean transformed into a z-
rejects a null hypothesis that is ACTUALLY
score)
TRUE
Type II Error: occurs when a researcher
fails to reject a null hypothesis that is
REALLY FALSE
Significant or Statistically Significant:
when a result is VERY UNLIKELY to occur
when the null hypothesis is true
Factors that affect significance
4. Make a decision based on if Beta: the probability of a type II error that
the z-score is in the critical cannot be specified as a single value and
region or not. depends in part on the size of the treatment
If it is in critical effect
region, reject H0 and Directional tests:
conclude that the One-tailed: the statistical hypothesis (H0
treatment has changed and H1) specify either an increase or
the pop. mean. decrease in the population mean
If it isn’t in the Make a statement about the direction
critical region, fail to of the effect
reject H0 because the Two-tailed tests:
data are not Effect size: intended to provide a
significantly different measurement of the absolute magnitude of a
from the null. treatment effect, independent of side of
Null hypothesis: states that in general sample(s) being used
population, there is no change, difference or Factors that affect effect size
relationship (EXACT OPPOSITE FROM Cohen’s d: one of the simplest and direct
ALT.) methods of measuring effect size
Has no effect on the DV
Alternative hypothesis: states that in
general population, there IS change,
