Question

Natalie created a pill to focus attention. She had a friend take the pill before writing her Spanish exam. She then had the same friend write her calculus exam without taking the pill. Natalie reviewed the test scores to see whether or not taking the drug increased her friend's performance. Which of the following best describes Natalie's experimental design?

1) Using a within-participants design, Natalie has minimized all possible external variables.
2) Natalie accurately created a control condition equal to that of the experimental condition, which will help validate her results.
3) Natalie inaccurately created a control condition, as it did not equal that of the experimental condition, discrediting her results.
4) Using a between-participants design, Natalie has minimized all possible effects external variables.

Answer 1

Option 3 is the best description of Natalie's experimental design, as the control condition was not equivalent to the experimental condition due to different exam subjects. To improve, she would need to use similar exams and a proper placebo control.

Step-by-step explanation:

Analysis of Natalie's Experimental Design

Natalie's experimental design in testing a pill for focusing attention by comparing test scores from a Spanish exam with a pill and a calculus exam without the pill can be critiqued as follows: Option 3 best describes Natalie's experimental design.

It is inaccurate to consider the control condition equivalent to the experimental condition because two different types of exams were taken, introducing extraneous variables that might affect performance unrelated to the effect of the pill itself. This discrepancy hinders the ability to attribute any performance differences solely to the pill, and thus discredits the results.

Furthermore, using a within-participants design can be a strength as it controls for individual differences between participants. However, without randomization and a proper placebo control, it's impossible to account for placebo effects or expectations of the participant.

Also, the lack of blinding could allow for experimenter bias to affect the results. Ideally, Natalie's friend should be unaware of when she is taking the pill or placebo, and the results should be observed by someone blind to the treatment conditions.

To improve the study, Natalie would need to implement an actual control condition where the friend takes a placebo before one of the exams and both exams should be of similar difficulty and subject matter. This would make the control condition more equivalent to the experimental condition, reducing the impact of extraneous variables on the test scores.