Which of the following study designs focuses on finding a cause and effect relationship among variables, but uses a lower level of control? Answer s: Response a. Phenomenology b. Experimental c. Descriptive d. Quasiexperimental Feedback: • Question 3 There is no measurable difference in incidence of incarceration for adolescent children whose mothers work outside the home in comparison with those whose mothers do not work outside the home. The above statement is an example of which of the following? Answer s: Response Feedback : a. Research question b. Research objective c. Aim of the study d. Null hypothesis A hypothesis is a formal statement of the expected relationship or relationships between two or more variables in a specified population. The null hypothesis, also referred to as a statistical hypothesis, is used for statistical testing and interpretation of statistical outcomes. The null hypothesis can be simple or complex and associative or causal.The null hypothesis states that there is no relationship between two or more variables. Extraneous variables exist in all studies and can affect the measurement of study variables and the relationships among them. Research objectives or aims are clear, concise, declarative statements that are expressed in the present tense, focus on one or two variables (or concepts), and indicate whether the variables are to be identified or described. A research question is a concise, interrogative statement that is worded in the present tense and includes one or more variables (or concepts). • Question 4 The report of a research study on a new medication to treat hypertension included this statement: “There was no significant difference in gender or age between the treatment and control groups.” Based on the statement, the reader of the report recognizes that gender and age were Answer s: Response a. demographic variables b. moderator variables c. confounding variables d. Environmental variables Age and Gender are demographic Feedback: variables • Question 5 How does a comparative descriptive design differ from a typical descriptive design? Answer s: Response Feedback : a. It differs in name only; they are essentially the same design. b. It compares changes in phenomenon over time, whereas the typical descriptive design focuses on only one time period. c. It examines the relationship between multiple variables, whereas a typical descriptive design only evaluates the effect of one independent variable on one dependent variable. d. It describes data from two different groups, whereas a typical descriptive design focuses on a single group. The commonly used descriptive study design examines characteristics of a single sample. It identifies a phenomenon of interest and the variables within the phenomenon,develops conceptual and operational definitions of the variables, and describes the variables. The comparative descriptive design examines and describes differences in variables in two or more groups that occur naturally in the setting. Descriptive statistics and inferential statistical analyses may be used to examine differences between or among groups. • Question 6 A study’s hypothesis that a new surgical approach produces safer outcomes in immunosuppressed patients is tested in a fourteen-site research study across the United States. Subjects at all sites are randomly selected and randomly assigned to experimental versus control groups. What study design is used in this research project? Answer s: a. Model testing design