Question

Devon wants to know if drinking milk before bed helps teenagers sleep. he chooses 10 friends on his high school basketball team for his study. every night for one month the friends drink a glass of milk before bed and later record how many hours they sleep that night. Describe three reasons why Devon's study design is flawed.

Answer 1

Three reasons why this design is flawed are that he is only surveying the basketball players. The population sample should include a mix of many teenagers if this is the hypothesis. The second reason this is flawed is that he is only collection data of ten people (whom are his friends), causing possible biased data and not enough evidence with only 10 people. Another flaw is the cup size. How much is each person drinking? Cups come on different sizes, but the amount should be the same for all.

Answer 2

The three reasons Devon's study is flawed because:

1. The sample size is very small. You cannot conclude anything based on small samples.

2. Sample is biased as Devon chose basket ball players and such players have proper sleep pattern and waking up pattern as compared to normal people. So, the study cannot be generalized.

3. Devon must have studied their sleep pattern before experimenting also, so that some quantitative data on change is available for conclusion.