Liberty Christian Academy Psyc 355 Exam 1 Questions 1-40
Question 1
... [Show More] 2.5 out of 2.5 points
A study found statistically significant results for a hypothesis tested with an independent-samples t test. The author of the study reported her effect size for the test as 0.82. According to Cohen's convention, this effect size is considered:
Selected Answer: Question 2 2.5 out of 2.5 points
A clinical researcher was interested in determining whether his interventions were effective in minimizing depression symptoms among his participants. To assess the effectiveness of his treatment program, he administered a depression inventory prior to his treatment and after his treatment. He hypothesized that depression scores would be lower at time two compared to time one. He then compared the mean differences between the two groups and found that his treatment was effective. The dependent variable in this study is:
Selected Answer:
Question 3 0 out of 2.5 points
The critical cutoff(s) for a two-tailed, paired-samplest test with 23 participants at a p level of 0.05 is (are):
Selected Answer: –
Question 4 0 out of 2.5 points
A researcher studies 45 volunteer citizens from a small community and asks them about the amount of caffeine (in milligrams) they ingest before and after lunch each day. The null hypothesis for this paired-samples study could be:
Selected Answer: Question 5 2.5 out of 2.5 points
When scientists call a hypothesis test conservative, they mean that it is:
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Question 6 2.5 out of 2.5 points
A researcher conducts a single-sample t test and finds statistical significance at the 0.01 level. The effect size is then calculated and found to be 0.04. What might you conclude about the findings?
Selected Answer: Question 7 2.5 out of 2.5 points
In a within-groups design where one group is measured twice over time, the appropriate hypothesis test is a(n):
Selected Answer: Question 8 0 out of 2.5 points
The comparison distribution for an independent-samples t test is a distribution of:
Selected Answer: Question 9 2.5 out of 2.5 points
According to the null hypothesis, the mean difference for the comparison distribution in a paired-samples t test is:
Selected Answer: Question 10 2.5 out of 2.5 points
A study found statistically significant results for a hypothesis tested with an independent-samples t test. The author of the study reported her effect size for the test as 1.24. What is true of the two sample means?
Selected Answer: Question 11 2.5 out of 2.5 points
We have learned three t tests, including all of the following except:
Selected AnswerQuestion 12 2.5 out of 2.5 points
Following are the results of an independent-samples t-test: t(18) = –2.11, p < 0.05. The results are:
Selected Answer: Question 13 2.5 out of 2.5 points
In a(n) ________, one sample is compared to a population for which we only know the mean during hypothesis testing.
Selected Answer: Question 14 2.5 out of 2.5 points
Twenty college students experience the effects of alcohol on reaction time. They perform very basic timed responses in a driving simulator both before and after consuming several alcoholic beverages. The researcher collects a reaction time result for each of the 20 students before and after intoxication, for a total of 40 measures. What are the degrees of freedom for this study?
Selected Answer: 19
Question 15 2.5 out of 2.5 points
Checking an independent-samples t test for the assumption of normality is part of step _____ of the six steps of hypothesis testing.
Selected Answer: Question 16 2.5 out of 2.5 points
In an independent-samples t test, how is the research hypothesis symbolized?
Selected Answer: Question 17 2.5 out of 2.5 points
In addition to reporting the results of statistical hypothesis testing, it is also recommended that researchers to report:
Selected Answer: Question 18 2.5 out of 2.5 points
What is the correct formula for using the sample standard deviation to estimate the population standard deviation?
Selected Answer:
Question 19 2.5 out of 2.5 points
A clinical researcher was interested in determining whether his interventions were effective in minimizing depression symptoms among his participants. To assess the effectiveness of two of his treatment programs, he administered a depression inventory after his treatment for two different groups of clients, each receiving a different treatment. He hypothesized that depression scores would be different between the two groups. The researcher's hypothesis is:
Selected Answer: Question 20 2.5 out of 2.5 points
To determine our critical values or cutoffs for an independent-samples t test, we use:
Selected Answer: Question 21 0 out of 2.5 points
Which of these is NOT an assumption of the paired-samples t test?
Selected Answer: Question 22 2.5 out of 2.5 points
Researchers were interested in whether relaxation training decreases the number of headaches a person experiences. They randomly assigned 20 participants to a control group or a relaxation training group and noted the change in number of headaches each group reported from the week before training to the week after training. The dependent variable in this study is:
Selected Answer: number of headaches.
Question 23 2.5 out of 2.5 points
Following are the results of an independent-samples t test: t(18) = –2.11, p < 0.05. In the current example, the degrees of freedom are:
Selected Answer: Question 24 0 out of 2.5 points
What is the formula for the paired-samples t test?
Selected Answer:
Question 25 2.5 out of 2.5 points
The correct formula for effect size using Cohen's d for a single-sample t test is:
Selected Answer:
Question 26 2.5 out of 2.5 points
The numerator (top portion) of the ratio for calculating all the t statistics contains:
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Question 27 2.5 out of 2.5 points
For the single-sample t test, the confidence interval is centered around the:
Selected Answer:
Question 28 0 out of 2.5 points
Mehl (2007) published in the journal Science the results of an extensive study of 396 men and women comparing the number of words uttered per day by each sex. Which statistical test should Mehl use to analyze the data?
Selected Answer: Question 29 0 out of 2.5 points
The formula for the total degrees of freedom for the independent-samples t test is:
Selected Answer.
Question 30 2.5 out of 2.5 points
When we know the population mean but not the population standard deviation, which statistic do we use to compare a sample to the population?
Selected Answer: t
Question 31 2.5 out of 2.5 points
The appropriate hypothesis test to use for a between-groups design with two groups is a(n):
Selected Answer:
Question 32 2.5 out of 2.5 points
The appropriate symbolic representation of corrected variance for a sample is:
Selected Answer
Question 33 2.5 out of 2.5 points
The mean of the comparison distribution for the null hypothesis of an independent-samples t test is:
Selected Answer
Question 34 2.5 out of 2.5 points
Which of the following statements is true about the assumptions of the independent-samples t test?
Selected Answer: they are identical to those for the single-sample and paired-samples t test.
Question 35 2.5 out of 2.5 points
Which of the following reports of statistical results are in appropriate APA format?
Selected Answer:
Question 36 2.5 out of 2.5 points
For an independent-samples t test, there were 14 participants in Group 1 and 17 participants in Group 2. The total degrees of freedom were:
Selected Answer: 29
Question 37 2.5 out of 2.5 points
Which of the following illustrates the correct APA format for reporting statistically significant results for an independent-samples t test?
Selected Answer:
Question 38 0 out of 2.5 points
According to the null hypothesis, the mean difference for the comparison distribution in a paired-samples t test is:
Selected Answer:
Question 39 2.5 out of 2.5 points
If a confidence interval is 95%, then this corresponds to a p level of _____.
Selected Answer:
Question 40 2.5 out of 2.5 points
A clinical researcher was interested in determining whether his interventions for depression were effective in minimizing depression symptoms among his participants. To assess the effectiveness of his treatment program, he administered a depression inventory prior to his treatment and after his treatment. He hypothesized that depression scores would be lower at time two compared to time one. He then compared the mean of the differences between the two groups to a known standard and found that his treatment was effective. Which statistical test was the researcher most likely to have used to test his hypothesis?
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