1. A psychologist is interested in investigating the effectiveness of a new training method for teaching self-care skills to developmentally disabled children. She designed a study in which one group of children received the new training method 5 days a week for a month. A second group received the new method 3 days a week. A third group did not receive the training. A blind rater counted the number of behaviors related to self-care performed by the children. For example, the rater counted the number of times the children dressed and groomed themselves independently. Each child’s self-care score was equal to the number of times they independently completed the self-care behaviors during the duration of the study.
2. A study was completed that examined the effectiveness of different methods of treatment for depression. Participants were randomly assigned to one of the following groups: One group received both psychotherapy and antidepressant medication. A second group received psychotherapy but no medication. A third group received medication but no psychotherapy. A fourth group received no treatment. Participants’ scores on a depression questionnaire were collected six months following the completion of their treatment.
3. A researcher wants to determine the relationship between physical fitness and weight. In order to do this, she weighs 100 participants. To measure physical fitness, the researcher records the number of hours of that each participant exercised in the past week. Finally, she calculates the relationship between weight (Kg) and hours of exercise.
4. A researcher wants to determine if growing up in a single parent household influences intellectual functioning in children. There is an established IQ test for children known as the Wechsler Intelligence Scale for Children (WISC) and the average score for children raised in a two-parent household is 100. The researcher gathers a sample of children...