Write a response to each discussion.
Pomajzl 4.2
Random sampling is defined as the process of drawing a research sample in which each member of a population has an equal chance of being selected (Erford p. 131). In other words, no outside factors are looked at other than an individual who is participating in a survey or study. As the term states, the participants are chosen at random as everyone within a specific population are able to participate without exclusions.
Random assignment is defined as, “the process of assigning individuals or groups to different conditions to maximize the probability that participant characteristics are matched between the experimental groups controlling for confounding variables,” (Erford p. 131).
Control groups can be used within research in an attempt to help find out differences for treatment. Control groups allow certain individuals to be part of a research study while falling within the guidelines of the treatment group. One example of this would be: individuals are chosen from random sampling. Following the random sampling, individuals are then divided into two groups based upon income to determine the most accurate results for both groups of individuals.
In terms of external validity, I feel that control groups are the most important. Anyone who is willing to assist with the study should be allowed to participate. Once selected, the individuals need to look at common factors in an attempt to categorize and divide individuals into specific groups.
Sperry 4.2
Sampling is important in all studies, it assists in providing internal and external validity. The wrong sample group in the study can make your results bias whether you are aware or not. It is vital that students understand the impact of the sample they chose. I will be defining and providing examples of random sampling, random assignment, and control groups.
Random sampling is selecting participants in the way that each population would be represented (Erford, 2015, p. 131). To give an example of random sampling would be similar to the lottery method. For example, if the city of Denver wanted to know if parents would be in favor of year-long school they would need to conduct a survey. One option would be to randomly select and mail surveys to parents who have children currently enrolled in Denver’s public school system.
Random assignment comes after participants are chosen to be part of the study (Erford, 2015, p. 137). This step is important because groups can be formed to test a variety of treatment conditions. For example, if researchers wanted to verify if green tea helps eliminate insomnia among middle age women. After middle age women who experience insomnia are selected they would then be assigned into an experimental or a control group without their knowledge. One set of women could drink the green tea before bed over several nights and the other group would get a placebo green tea to take for several nights.
Control groups are used by researchers to provide reference groups for experimental treatment groups. Researcher will use a no-treatment control group or placebo control group to maximize the outcome of a treatment when compared to the treatment group (Erford, 2015, p. 130). A good example for using control groups is with patients who wish to stop smoking. You could give one group a smoking cessation medication and the other group would take a placebo.
After in-depth examination of all three methods, in my opinion, I would favor random assignment sampling. With random assignment sampling, you verified that all individual have the same qualifiers that are significant to the study. From this point on it would give me a good “base” to start from. It would eliminate bias and ensure validity.