Agroup of overweight people are asked to participate in a weight loss program. participants can choose whether they want to go on a vegetarian diet or follow a traditional low-calorie diet that includes some meat. half of the people choose the vegetarian diet, and half choose to be in the control group and continue to eat meat. suppose that there is greater weight loss in the vegetarian group. complete parts (a) and (b) below.
a. suggest a plausible confounding variable that would prevent us from concluding that the weight loss was due to the lack of meat in the diet. explain why it is a confounding variable.
a. people who are not prepared to change their diet very much(such as by excluding meat) might also not change other factors that affect weight, such as how much exercise they get.
b. heavier people are more likely to seek out weight loss programs. therefore, weight loss may be due to having a dedicated mindset instead of the level of meat in the given diets.
c. the meals administered under the program may not be of highquality, which may affect the eating habits of people who would otherwise succeed in following the vegetarian diet.
d. those who choose to follow a vegetarian diet may have a more difficult time adjusting to their diet than those who are still able to consume meat.
b. explain a better way to do the experiment that is likely to remove the influence of confounding variables.
a. the experiment would be improved if some subjects were randomly assigned to eat meat and the remaining subjects to consume a vegetarian diet.
b. the experiment would be improved if some subjects were notoverweight, to ensure that any confounding variables associated with being overweight were eliminated.
c. the experiment would be improved if the subjects had to stay at a facility to prevent the possibility of cheating on the diet.
d. the experiment would be improved if the researchers were unable to interact with the participants and introduce possible bias.