Exam 2 Flashcards
Single Sample T-test
When comparing a random single sample to a population when population standard deviation is known
What is the Z critical value for a one-tailed test
+/-1.645
What is the Z critical value for a two-tailed test
+/-1.96
Descriptive Statistics
numerical measures that describe a distribution by providing information on the central tendency of the distribution, its width, and its shape.
Inferential Statistics
A procedure that draws a conclusion about a population based on a sample
Alpha level
0.05. Compare alpha level to results in order to know whether to reject or fail to reject the null
Power
probability of correctly rejecting a false null. More power=more likely to confirm the alternative hypothesis
Statistical significance
An observed difference between the two descriptive statistics is unlikely to occur by chance. Probability of a type 1 error is small
Critical value
Value of a test statistic that marks the edge of the region of rejection in a sampling distribution. Values equal to or beyond the critical value fall within the region of rejection.
Effect size
the proportion of variance in the dependent variable that is accounted for by the manipulation of the independent variable
Statistically significant p-value
less than 0.05
Statistically significant Z value
beyond the Z critical value
R^2= at least 0.01
small
R^2= at least 0.09
Medium
R^2= at least 0.25
Large
