RESEARCH STUDY 10.2
Dr. Bloedorn is a health psychologist who researches nutrition. She is curious as to whether a new drink additive will help people consume fewer calories during a meal. The drink additive is a white, odorless, tasteless powder that a person can add to any drink. She collects a random sample of 63 overweight students on campus and measures the calories they eat during lunch, using a bomb calorimeter. She then gives this additive to the same 63 participants to use at dinner and measures how many calories they eat (again, using the bomb calorimeter).
-Refer to Research Study 10.2 above to answer the following question. The addition of a group that does not use the drink additive but adds a similar-looking substance that they think is the additive would help Dr.Bloedorn address which of the following threats to internal validity?
A) History
B) Observer bias
C) Instrumentation
D) Placebo effects
E) All of the above

Question

Quizplus · Accepted Answer

The addition of a group that does not use the drink additive but adds a similar-looking substance that they think is the additive would help Dr. Bloedorn address the threat of placebo effects, where participants may alter their behavior based on their belief about the treatment rather than the actual treatment itself. By using a placebo group, Dr. Bloedorn can compare the actual effect of the additive to the effects caused by the placebo effect.

RESEARCH STUDY 10.2 Dr. Bloedorn Is a Health Psychologist Who Researches Nutrition. She