Question

For each of the following situations, identify the type of threat to internal validity from the list.

Answer 1

Answer:

a) The researcher tested the effectiveness of a new method of teaching drug dosage and solution calculations to nursing students using a standardized calculation examination at the beginning, midpoint, and end of a 2-week course. - MATURATION.

b) In a study of the results of a hypertension teaching program conducted at a senior center, the blood pressures taken by volunteers using their personal equipment were compared before and after the program. - INSTRUMENTATION.

c) The smoking cessation rates of an experimental group consisting of volunteers for a smoking cessation program were compared with the results of a control group of people who wanted to quit on their own without a special program. - SELECTION BIAS.

d) Thirty percent of the subjects dropped out of an experimental study of the effect of a job- training program on employment for homeless women. Over 90% of the dropouts were single homeless women with at least two preschool children, whereas the majority of subjects successfully completing the program had no preschool children. - MORTALITY