Do energy snack bars improve afternoon alertness? 100 factory workers were randomly assigned to two groups.One group ate energy snack bars at lunch and the other group ate placebo snack bars.At the afternoon break (approximately 1-1/2 hour after lunch), a significant increase in alertness was observed.Later analysis of the experiment results showed 87% of the participants exhibiting increased alertness were from the group which ate
Energy snack bars.
A)Double blind
B)Single blind, only participant is blinded
C)Single blind, only evaluator is blinded
D)Neither

Question

Quizplus · Accepted Answer

The experiment is double-blind because neither the participants nor the evaluators know which group is eating the energy snack bars and which group is eating the placebo snack bars.

Do Energy Snack Bars Improve Afternoon Alertness? 100 Factory Workers