In conducting a study on parental involvement and the affect it can have on student academic achievement, the following factors can create a threat to internal validity and create limitations in the results of the study:
- Subject Attrition
- Statistical Regression
- Experimenter effects
- Subject effects
Participant Selection and Statistical Regression
The study on parental involvement will involve teachers and parents of students in grades fourth (4), sixth (6), and ninth (9). To complete the study we will administer a survey and conduct an interview with the parents and teachers of the students. In order to select the sample population of parents to participate in the study, we will ask the teachers to provide the names of parents that maybe interested in completing the study. The sample population can pose a threat to validity if the teacher does the following:
- Only provide names of parents who are involved in the students academic success
- Provide the names of parents who are involved and not involved, but provide a greater number of parents who are involved.
If the teacher provides a greater list of names of involved parents than, non-involved parents it will create a sampling error and selection bias because the two groups will be unevenly represented. In this case, the teachers will control the sample population and in some instance, could provide the names of parents that only have the characteristics in favor of what the study is analyzing, which leads to statistical regression.
Statistical regression can pose a threat to validity because the list of participants provided by the teachers may have been provided because the parents are involved with the student’s academic success. In another instance, to complete the study we will contact the guidance counselors at the school for test scores of students to draw comparisons. If the guidance counselor only selects the scores for students with high-test scores, it can pose a threat to validity in the study because favorable or misrepresenting information was provided to be analyzed.
During the study, numerous uncontrolled events could occur that can affect the outcome of the results. For instance, if the parent or teacher participating within in the study occurs a major crisis, such as death, illness, loss of employment, a major move, or other natural, uncontrollable occurring event, this can result in a fluctuation of test scores for the students of the parents. The event can also hinder the parents or teachers from participating in the study, leading to subject attrition.
Subject Attrition, Subject Effects, and Instrumentation
The study will relies heavily on the ability of the parent and teacher to respond to interview questions and a survey. If the participants encounter a naturally occurring event that can potentially hinder them from responding, this may lead to subject attrition, in which the participant drops out of the study. Subject attrition can affect the validity of the study because non-responses and non-participation from participants will affect the results.
In the interview, the researcher will be aware of the participants’ ability to provide unrealistic information during the observational process to prevent the threat of subject effects on validity. During the process, if the participant has an idea of the purpose of the study, they may answer the questions in a way that is untruthful and present themselves favorable to the results of the study. The change in behavior will affect the results of the study and can lead to a threat on validity due to instrumentation. If the interviewer or observer becomes bored or tired during the process, the behavior could change the response and thus affect the results.
In analyzing the results of the study, the researcher will consider the affect of experimenter effects on validity, by not stating assumptions. For instance, if the study reveals that parents are involved in the student’s academic life, it does not mean the student is successful academically. The researcher will not draw conclusions based on the results provided, because there can be other underlying factors that could contribute to the success or failure rate of a student. The researcher will ensure that all factors have been considered before analyzing the results. The researcher will use supplemental questions during the interview process that will identify the underlying factors or other confounding variables that can affect the results of the study.