Question

In the description of the following experiment, determine the experimental factor. During a study testing a new vaccine for Zika virus, the research team grouped the volunteers enrolled for the test into Group A and Group B. Group A received an inert drug (placebo) while Group B received the vaccine.

Select the correct answer below:

whether or not a person contracts the Zika virus

the effectiveness of the new vaccine

the drug received by each group

the group receiving the new vaccine

Answer 1

The answer is:

So to answer this question we have to first understand what experimental factors are. These are basically variables that vary between the different experimental groups/samples and are thus required to draw valid conclusions from the experiment. Now in the above question, we can see that "the drug received by each group" is the experimental factor which is the only variation between the two groups. One group receives the placebo while the other group receives the vaccine.

All other options do not make much sense.

• Option1 is wrong as we are not injecting volunteers with Zika virus
• For Option2, we are testing for the effectiveness of the drug but that is not an experimental factor. That is more like the result.
• Option 4 is wrong because we compare between groups

Please upvote. Let me know in the comments if anything is unclear. I will reply ASAP!