Consider the following studies: Study 1: A study was conducted to investigate th
ID: 3200454 • Letter: C
Question
Consider the following studies: Study 1: A study was conducted to investigate the effectiveness of taking Zyban when trying to quit smoking. 429 smokers volunteered to take part in the study. Due to concerns that living with another smoker may alter the effectiveness of the treatment, the volunteers were initially split into two groups depending on whether or not they lived with another smoker. Each of the two groups was then randomly split in half, with one half allocated to take Zyban and the other half allocated to take a placebo. The percentage of people in each group that managed to successfully stop smoking after a year was recorded. Study 2: A study was conducted to investigate the effects of playing video games on visual skills. 16 young men took a series of tests that measure their visual skills. They were then asked whether or not they had played video games in the last 6 months. It was found that the men who had played games within the previous 6 months performed better on the tests than those who hadn't played. Answer the following questions for each study: Identify the groups that are being compared. (I.e., what treatments or factors of interest are being compared?) DO NOT also say what is being measured to make the comparison - you do this in (ii). What is being measured to compare these groups? ONLY describe the variable being measured. DO NOT also mention the groups being compared. Would you describe the study as an experiment or an observational study? If it was an experiment, what part of the study design led you to this conclusion? If it was an observational study, could an experiment have been easily carried out instead? If so, briefly explain how. If not, briefly explain why not Which of the studies, if either, used blocking? For either study in which blocking was used, describe what was blocked. Which of the studies, if any, used a control group? For any studies that do, describe the control group. After study 2 was completed a school newspaper runs the headline "Video games cause improved visual skills in young adults". Give two reasons why this headline is not appropriate.Explanation / Answer
(a)
(i) Study 1:
The groups that are being compared - What treatments or factors of interest are being compared:
One group allotted to take Zyban and the other group allotted to take placebo.
Study 2:
The groups that are being compared - What treatments or factors of interest are being compared:
Men who played videogames within the previous six months and
Men who had not played videogames within the previous six months.
(ii) What is being measured to compare the groups:
Study 1:
Percentage of people in each group who managed to successfully stop smoking after a year.
Study 2:
series of test that measure their visual skill
(iii)
Study 1:
The study is an experiment and not an observational study.
REASON:
In an experiment, investigators apply treatments to experimental units and then proceed to observe the effects of the treatments on the experimental units.
In observational study, investigators observe subjects and measure variables of interest without assigning treatments to the subjects.
Here, half of the volunteers were allotted to take Zyban and the other half allotted to take placebo.
Study 2:
The study is an observational study and not an experiment.
EXPLANATION:
This could have been made as experiment by partitioning the persons into two groups: one asked to do videogame for 6 months and other group not to do videogames for 6 months. After 6 months, their visual skills must be tested and appropriate conclusion drawn.
SINCE THE ANSWER IS LONG, ONLY FIRST QUESTION IS ANSWERED AS PER DIRECTIONS FOR ANSWERED.