High Internal Validity Shows Re Socw6311 Response
Due 03/20/2019
Respond to at least two colleagues by explaining how that colleague might rule out one of the confounding variables that they identified. (Use 3 APA reference, Be very detailed in response and you have references from week 4 initial post or you can use three alternate APA reference which apply)
Response to Kynesha
Post an interpretation of the case study’s conclusion that “the vocational rehabilitation intervention program may be effective at promoting full-time employment.”
A study was conducted to evaluate a vocational rehabilitation program for inmates that were recently released on parole. A quasi-experimental research design was used to evaluate the program (Plummer, Makris & Brocksen, 2014). 30 individuals (intervention group, independent variable) were enrolled to begin participating while 30 additional participants (comparison group, dependent variable) were placed on a waiting list. Data was received from surveys that were filled out by each individual’s probation officer and returned to the researchers. The surveys included information about demographics and employment level, none, part-time or full-time (Plummer, Makris & Brocksen, 2014).
Describe the factors limiting the internal validity of this study. Explain why those factors limit the ability to draw conclusions regarding cause and effect relationships.
Researchers identified two factors that limit the internal validity. These two factors are “that 1) no random assignment was used, and 2) it is possible that differences between the groups were due to preexisting differences among the participants (such as selection bias)” (Plummer, Makris & Brocksen, 2014). The sole purpose of the study was to see if the vocational program would be beneficial and/or have an effect on parolee’s, but when you consider the limitations, the validity of the study then decreases (Dudley, 2014). A control group or randomly chosen participants would have provided more validity and reliability to the research study because there would not be any bias in the study (Dudley, 2014). Each participant would have not had any knowledge regarding explicit details of the study nor would they have a way to prepare for the study beforehand. According to the researchers, the program was still found to be effective for the participants (Plummer, Makris & Brocksen, 2014). However, utilizing a control group would create an unbiased pool of participants which in return will give the researcher more accuracy when measuring the different factors and evaluating the outcomes to see if the program is effective or not (Dudley, 2014).
References
Dudley, J. R. (2014). Social work evaluation: Enhancing what we do. (2nd ed.) Chicago, IL: Lyceum Books.
Plummer, S.-B., Makris, S., & Brocksen S. (Eds.). (2014b). Social work case studies: Concentration year. Baltimore, MD: Laureate International Universities Publishing. [Vital Source e-reader].
Response to Meghan
Interpretation of Results
In the Chi-Square case study, the researchers aim to evaluate the outcome of a new vocational rehabilitation program (Plummer, Makris, & Brocksen, 2014b). The researchers utilized a quasi-experimental research design. The researchers included 30 individuals currently enrolled in the program which were noted as the intervention group. The 30 individuals who were waiting to enroll in the program after the first 30 completed were noted as the comparison group. The independent variable was participation in the group and the dependent variable was the employment outcome. By utilizing a Pearson chi-Ssquare the researchers compared the two groups (intervention group and comparison group). It was found that only five participants did not gain employment with participation in the program, seven found part-time jobs, and 18 found full-time job. In the comparison group, who were waiting for the program, 16 were unemployed, seven were employed part-time, and only six were employed full-time. The results of the Pearson chi-square show that the vocational rehabilitation is highly likely to be effective in helping paroled inmates gain full-time employment (Plummer, Makris, & Brocksen, 2014b).
Factors Limiting Internal Validity
Having high internal validity shows strong evidence of causality (Dudley, 2014). Factors that limit internal validity are that there was no random assignment and possible selection bias (Plummer, Makris, & Brocksen, 2014b). When there is no random sampling, all possible options were not explored and did not have an equal chance to participate in the study (Dudley, 2014). When random assignment is not utilized in a study, it appears that there is more chance for bias by the researchers. Utilizing random assignment in gaining the participants for the study would help increase the validity and reliability of the results (Dudley, 2014).
References
Dudley, J. R. (2014). Social work evaluation: Enhancing what we do. (2nd ed.) Chicago, IL: Lyceum Books.
Plummer, S.-B., Makris, S., & Brocksen S. (Eds.). (2014b). Social work case studies: Concentration year. Baltimore, MD: Laureate International Universities Publishing. [Vital Source e-reader].