Question

COLLECTING DATA
2.

2A.

To test the effectiveness of a liquid supplement that is supposed to help forgetful people with their memory, 400 college students are recruited for a study and divided into two groups. Group A with 250 students receives the supplement, while group B with 150 students receives some colored water. Neither group is told what they received. After several weeks, they are given a memory test. This study can best be described as

• a controlled placebo experiment
• the placebo effect
• a survey using quota sampling
• a census
• a survey using simple random sampling

2B.

To test the effect of a new exercise routine on muscle growth, a researcher sets up the following experiment: 60 volunteers subjects (40 men and 20 women) of average build are selected to participate in the study. Their body mass and muscle sizes (biceps, thighs, etc.) are measured. The researcher gives all the men a DVD with the new exercise routine, and the women a DVD with a standard routine, but only the researcher knows this.

The results of the experiment are likely to be invalid mostly because

• the treatment group and control group were not the same size.
• the subjects were volunteers.
• the subjects did not know if they were getting the real treatment.
• the gender of the patient is a confounding variable in this experiment.
• None of the above

Answer 1

A controlled Placebo experiment

This is because group B was just given some colored water and group A was given the required supplement that is one group receives the treatment which is being tested and other just a placebo effect of it.

Hence, a controlled Placebo experiment.

The gender of the patient is confounding variable in the experiment.

It may happen that the new muscle routine is suitable just for boys and hence giving woman a standard routine or a new routine won't help, so the overall conclusion would be wrong.

Thank you !!