EXAM QUESTIONS
Q2. A proportion is the mean of a variable that is 1 when the individual has a characteristic and 0 otherwise. The standard deviation of any variable is given by:
The mean of n of these observations give the sample proportion. The standard error of the proportion is expressed as the SD of one of them divided by the square root of the sample size or by the formula:
Standard error of the mean is the estimation of the variability that exists between sample means that are obtained from picking multiple samples from same population. The variability between the samples is estimated by the standard error whereas the variability within a single sample is measured by the standard deviation. Lower values of the standard error of mean indicate that the estimates of the population mean are more precise. If the standard deviation is large, the mean estimate is less and hence the standard error of the mean is large (McKillup, 2005). The two concepts have been used in the case in https://learn.bu.edu/bbcswebdav/pid-826908-dt-content-rid-2073693_1/courses/13sprgmetcj702_ol/week04/metcj702_W04S01T07a_cj.html
Q4. When conducting an experiment involving human test subject, there are steps the researcher must take to ensure that the human subjects will not be harmed. While conducting an experiment on prison inmates to determine if an anger management program has improved their rate of recidivism I would follow the following steps to ensure that the prisoners are not harmed. I should first understand that it is a fundamental responsibility of protecting the prisoners from physical harm in my research. As a researcher, I should be harmed with the knowledge of the BPS Code of Ethics and Conduct which bases on 4 principles of ethics: competence, respect, integrity and responsibility (Hornblum, 1997). The participants expect me to adhere to all those plus guaranteeing confidentiality of their responses. Then I will make the prisoners understand the purpose of the study am undertaking. The prisoners should have been informed about my study before I could appear such that whoever is not willing to participate has the right to withdraw. This is necessary for them to be aware of the potential stress, harm or any other related issue. I should be careful not to introduce any form of social prejudice. I should take time to understand the linguistic, religious, cultural, gender and other differences between the participants. In case the prisoners get stressed in the research course, I should be flexible to either postpone the interview or even withdraw.
Q5. Negative Correlation means that two variables are inversely correlated. When one variable increases, the other variable decreases and vice versa. A good demonstration of negative correlation is best when conducting research on the relationship between performance of students in a school and the playing of video games. The GPA of the students are recorded against the hours that the student has spent in playing video games.
It is clearly evident that as the number of the hours that the student has spent playing video games increases, the GPA on the other hand decreases. This correlation is a negative one. The common measure of correlation is by the Pearson product moment correlation represented by the letter r. A correlation has two qualities: direction and strength. A negative sign precedes negative correlations. In order to shift the correlation to positive i.e. such that the GPA of the students increases with increase in the number of the hours spent in playing video games, the variables should be treated such that they decline towards zero or no correlation. Negative correlation does not imply a causal relationship as the state of the variables fluctuate with time (McKillup, 2005).
References
David Weisburd, Chester Britt (2013). Statistics in Criminal Justice. Berlin: Springer Science & Business Media - Social Science - 783 pages
Hornblum A., (1997). They were cheap and available: Prisoners as research subjects in twentieth century America. British Medical Journal. 1997; 315:1437–1441. [PMC free article] [PubMed].
Steve McKillup (2005). Statistics Explained: An Introductory Guide for Life Scientists. Cambridge University Press, 15 Dec 2005 - Medical
