Reading and interpreting research literature

Gance-Cleveland's study, "Qualitative Evaluation of a School-Based Support Group for Adolescents With an Addicted Parent" (2004), examines the experience of two Midwestern suburban high schools with existing student-based support groups (SBSGs). No other specific inclusion or exclusion criteria were used (beyond study site).

The author observed all participants in two SBSGs. Sites were not chosen using probability techniques, but rather picked because of experience with SBSGs for adolescents who have addicted parents. Gance-Cleveland also used theoretical sampling, a non-probability technique, in interviewing participants and co-facilitators to inform her study.

For this qualitative study, the author reported a total of 20 participant observations of 4 hours duration at two high schools. She also conducted 13 interviews and received written evaluations from 8 students. The observations, associated interviews, and written evaluations took place over one semester. The sample size, while small, is adequate for a descriptive study such as this one.

As noted above, data collection instruments included participant observation, interviews with participants and stakeholders (including administrators, consultants, and co-facilitators), one focus group, and written evaluations. Participant observations were conducted weekly over one semester, and the substance-abuse consultant was interviewed after each session in order to clarify the observations. Other data was collected at various times over the semester: the author conducted interviews with the program administrator and a school vice principal at the beginning of the semester; written evaluations were collected from participants at the final session; and targeted interviews with the substance abuse consultant, co-facilitators, and three student participants took place at the beginning, middle, and end of the study.

To safeguard the ethical rights of the subjects, Gance-Cleveland received approval by an institutional review board (IRB) and obtained consent from all subjects before conducting interviews. The sampling methods ensure a fairly natural atmosphere, with participants participating in the SBSGs and the study at will. However, these methods also limited the representativeness of the study since it did not include those who either neglected to participate or dropped out of the groups.

Research Report: Ridge and Goodson

The Ridge and Goodson study, "The Relationship Between Multidisciplinary Discharge Outcomes and Functional Status After Total Hip Replacement" (2000), takes place in an academic medical center. Inclusion criteria required the patient to be planning to undergo total hip replacement during the study period. Of those eligible, 25 declined to participate. Further exclusion criteria included a lack of English language proficiency and being under 40 years of age, which left a total of 24 eligible participants. Of these, 21 returned usable surveys and were included in the final sample.

This is a descriptive sample, representing a non-probability sampling design technique. The authors chose their sample based on prospective patients at one hospital, who were available and willing to participate during the study time frame. As such, these subjects may differ from a strictly random sample of the general surgical population.

Ridge and Goodson followed 21 subjects out to three months post-surgery. For this type of quantitative study, where researchers look for statistically significant outcomes, the small sample size could make reaching statistical significance difficult. However, even with a smaller than ideal sample size, researchers did find a number of statistically significant outcomes.