CORRECT
Type I error (alpha) - Answer-False positive results
ex: reject the null hypothesis when you should accept it
/.Type II error (beta) - Answer-False negative results
ex: accept the null hypothesis when you should reject it
/.Which inferential test should be used to compare two sample means to each other? -
Answer-the two-sample t-test
/.the most important difference between cohen's d and the t-test is that cohen's d -
Answer-is not affected by sample size
/.what is the formula for the degrees of freedom (df) for a two-sample t-test? - Answer-n-
2
/.if a researcher wants to compare the effects of an antidepressant to the effects of a
placebo on levels of anxiety, then what is the independent variable (that is, the IV)? -
Answer-medication: antidepressant vs. placebo
/.when the means of two groups are the same, then Cohen's d... - Answer-will equal 0
/.A two sample t-test is an appropriate test when.. - Answer-two samples are being
compared on an interval or ratio level variable
/.imagine that a researcher conducts a one-tailed (i.e., directional) two-sample t-test
with a critical value of -1.83 and gets an observed value (or test value) of t=+1.98. What
is the proper conclusion in this case? - Answer-retain the null hypothesis
/.cohen's d indicates the number of... - Answer-standard deviations between two means.
/.if a researcher wants to compare the effects of an antidepressant to the effects of a
placebo on levels of anxiety, then what is the dependent variable (that is, the DV)? -
Answer-Levels of anxiety
/.if a researcher gathers data from participants before and after they participate in an
exercise training program and wants to know whether their performance scores
improved, then he should use... - Answer-a one-tailed, repeated measures t-test.
, /.if a research conducts an inferential test (such as a t-test) and retains (i.e., fails to
reject) the null hypothesis, then what is the probability of a Type I error? - Answer-0.00
/.one assumption of the two-sample t-test is that... - Answer-the two samples are
independent of one another
/.imagine that a researcher conducts a two-sample t-test with a critical values of +/- 2.10
and gets an observed value (or test value) of t=1.98. What is the proper conclusion in
this case? - Answer-retain the null hypothesis (still in the range of variation for sampling
error)
/.if a researcher wants to compare the effects of an antidepressant to the effects of a
placebo on levels of anxiety, then what is the grouping variable? - Answer-medication:
antidepressant vs. placebo (IV/grouping variable)
/.the comparison group in a repeated measures t-test is... - Answer-each person's own
score at time 1.
/.imagine that a researcher conducts a repeated measures t-test with critical values of
+/- 2.78 and gets an observed value (or test value) of t= -3.30. What is the proper
conclusion in this case? - Answer-reject the null hypothesis
/.when the means of two samples are being compared and cohen's d=0, then... -
Answer-the means are identical
/.if a research conducts an inferential test (such as a t-test) and rejects the null
hypothesis, then what is the probability of a Type II error? - Answer-0.00
/.If n= infinity, then what is the critical value of t for alpha = .05? - Answer-+/-1.96
/.If a researcher conducts a t-test with an alpha of .01 and gets a p-value of .25, then
the researcher should... - Answer-retain (i.e, fail to reject) the null hypothesis
/.if you want to compare the means of two different groups to each other then you
should use... - Answer-a two-sample t-test
/.as the means of two groups become more similar, cohehn's d will... - Answer-approach
0
/.if you conduct a one-tailed (i.e., directional) two-sample t-test with a critical value of
+2.20 and gets an observed value of t=-3.53, then what should you do? - Answer-retain
the null hypothesis
/.If you conducted an experiment to compare the effects of two different online ad
campaigns on the number of clickthroughs (i.e., how often people clicked on each ad),
then what is the dependent variable (DV)? - Answer-the number of clickthroughs