Question

9. What are the three required assumptions for the appropriate use of the independent groups t-test? What are the three required assumptions for the appropriate use of the dependent groups t-test? Can you use these tests when you have three groups? What test do we use instead? Can the dependent variable be nominal? What should the nature of the dependent variable be?

Consider your answers to the previous question when you answer the next two questions:

10. For which of the following situations is the independent groups t-test appropriate (if inappropriate, why?): a. The independent variable is infant birth weight at one week (normal vs high); the dependent variable is resting heart rate. b. The independent variable is radiation treatment on the same throat cancer patients (after a low dose and then a high dose treatment); the dependent variable is white blood cell count. c. The IV is infant birth weight (low vs normal vs high); the DV is number of days absent from school in first grade. d. The IV is gender (male vs female); the DV is compliance vs noncompliance with a medication regimen. e. The independent variable is married status (single vs married); the dependent variable is happiness measured on a scale from 1 to 50

11. For which of the following situations is the dependent groups t-test appropriate (if not appropriate, why?) a. The IV is presence or absence of conversation directed to comatose patients (same patients with and without conversation); the DV is the patients’ intracranial pressure. b. The IV is birth type (home vs hospital); the DV is perceived functional ability of the patient 48 hours after surgery. c. The IV is time since incarceration (1 months vs 3 months vs 6 months); the DV is body weight. d. The IV is menopausal state (pre vs post) in the same women over time; the DV is attitudes toward menopause. e. The IV is nap therapy for narcoleptics (same patients before vs after treatment); the DV is the type of nap they had the following week (had unplanned vs didn’t have unplanned nap).

Answer 1

Answer:

9. What are the three required assumptions for the appropriate use of the independent groups t-test?

The populations from which the samples were obtained must be normally or approximately normally distributed.

The samples must be random and independent.

The variances of the populations must be equal.

What are the three required assumptions for the appropriate use of the dependent groups t-test?

The data are continuous (not discrete).

The data, the differences for the matched-pairs, follow a normal probability distribution.

The sample of pairs is a simple random sample from its population. Each individual in the population has an equal probability of being selected in the sample.

Can you use these tests when you have three groups? What test do we use instead?

No, these tests are not used. We have to use ANOVA test.

Can the dependent variable be nominal? What should the nature of the dependent variable be?

No, dependent variable should be atleast in interval scale.

Consider your answers to the previous question when you answer the next two questions:

10. For which of the following situations is the independent groups t-test appropriate (if inappropriate, why?):

a. The independent variable is infant birth weight at one week (normal vs high); the dependent variable is resting heart rate.

Appropriate

b. The independent variable is radiation treatment on the same throat cancer patients (after a low dose and then a high dose treatment); the dependent variable is white blood cell count.

Appropriate

c. The IV is infant birth weight (low vs normal vs high); the DV is number of days absent from school in first grade.

Inappropriate, there are 3 groups(low vs normal vs high).

d. The IV is gender (male vs female); the DV is compliance vs noncompliance with a medication regimen.

Inappropriate, DV is not continuous.

e. The independent variable is married status (single vs married); the dependent variable is happiness measured on a scale from 1 to 50

Appropriate

11. For which of the following situations is the dependent groups t-test appropriate (if not appropriate, why?)

a. The IV is presence or absence of conversation directed to comatose patients (same patients with and without conversation); the DV is the patients’ intracranial pressure.

Appropriate

b. The IV is birth type (home vs hospital); the DV is perceived functional ability of the patient 48 hours after surgery.

Inappropriate,( there are two groups that are compared.)

c. The IV is time since incarceration (1 months vs 3 months vs 6 months); the DV is body weight.

Inappropriate,( there are three scores on same subject, that are compared.)

d. The IV is menopausal state (pre vs post) in the same women over time; the DV is attitudes toward menopause.

Appropriate

e. The IV is nap therapy for narcoleptics (same patients before vs after treatment); the DV is the type of nap they had the following week (had unplanned vs didn’t have unplanned nap).

Inappropriate, DV is not continuous.