Two-Sample T-Tests
Two-Sample t-Tests
Connie Tyrone
Walden University
August 24, 2013
Two Sample t-Tests With this assignment, we are told about Martha. Martha wants to see if her relaxing technique which involves visualization will be able to assist people suffering with mild insomnia to fall asleep faster. She randomly selects 20 insomnia patients to participate in her research. She assigns 10 from the group to participate in visualization therapy and 10 from the group receives no treatment. Martha then keeps a record of how long it takes each participant to fall asleep. As follows:
No Treatment (X1) Treatment (X2)
22 19
18 17
27 24
20 21
23 27
26 21
27 23
22 18
24 19
22 22
Our assignment is to respond to the following questions regarding Martha’s research study and her data.
Should Martha use an independent-samples t-test or a related samples t-test? Explain your answer. Martha should use an independent-samples t-test. The independent-samples t-test is “the parametric procedure used for significance testing of sample means from two independent samples” (Heiman, 2012, p. 122). In Martha’s case, she has chosen 20 patients in which half will receive visualization therapy and half will not.
What are the independent and dependent variables? The independent variable in this case is the amount of therapy. The dependent variable is how long it takes for the patient to fall asleep.
Using the fact that Martha believes the treatment will reduce the amount of time to fall asleep, state the null and alternate hypotheses.
Null hypothesis (Ho) says “the sample data represent the μ that’s found when the predicted relationship is not present” (Heiman, 2012, p. 93). “It states that changing the independent variable does not produce the predicted differences in dependent scores in the population” (Heiman, 2012, p.93). Martha believes that with treatment (independent variable), the treatment will reduce the amount of time to fall asleep,
Connie Tyrone
Walden University
August 24, 2013
Two Sample t-Tests With this assignment, we are told about Martha. Martha wants to see if her relaxing technique which involves visualization will be able to assist people suffering with mild insomnia to fall asleep faster. She randomly selects 20 insomnia patients to participate in her research. She assigns 10 from the group to participate in visualization therapy and 10 from the group receives no treatment. Martha then keeps a record of how long it takes each participant to fall asleep. As follows:
No Treatment (X1) Treatment (X2)
22 19
18 17
27 24
20 21
23 27
26 21
27 23
22 18
24 19
22 22
Our assignment is to respond to the following questions regarding Martha’s research study and her data.
Should Martha use an independent-samples t-test or a related samples t-test? Explain your answer. Martha should use an independent-samples t-test. The independent-samples t-test is “the parametric procedure used for significance testing of sample means from two independent samples” (Heiman, 2012, p. 122). In Martha’s case, she has chosen 20 patients in which half will receive visualization therapy and half will not.
What are the independent and dependent variables? The independent variable in this case is the amount of therapy. The dependent variable is how long it takes for the patient to fall asleep.
Using the fact that Martha believes the treatment will reduce the amount of time to fall asleep, state the null and alternate hypotheses.
Null hypothesis (Ho) says “the sample data represent the μ that’s found when the predicted relationship is not present” (Heiman, 2012, p. 93). “It states that changing the independent variable does not produce the predicted differences in dependent scores in the population” (Heiman, 2012, p.93). Martha believes that with treatment (independent variable), the treatment will reduce the amount of time to fall asleep,