| Date | May 2022 | Marks available | 1 | Reference code | 22M.1.SL.tz0.29 |
| Level | Standard Level | Paper | Paper 1 | Time zone | time zone 0 |
| Command term | Question number | 29 | Adapted from | N/A |
Question
A study investigated the effects of a carbohydrate-rich mouthwash on soccer players. The investigators used a double-blind protocol. What characterizes a double-blind study?
A. The investigators and participants know who is given the carbohydrate-rich mouthwash.
B. The investigators know which participants are given the carbohydrate-rich mouthwash but the participants do not.
C. Neither the investigators nor the participants know which participants are given the carbohydrate-rich mouthwash.
D. The investigators know which participants are given a placebo but the participants do not.
Markscheme
C
Examiners report
This was the second easiest question on the paper with most candidates accessing a mark. C was the correct answer and A discarded by most as an incorrect answer.
