Question

What are some possible lurking variables for this scenario?

a. Researchers found that adults going out to eat after 9:00 PM tend to wake up the next morning with headaches more often. They conclude that cating out after 9:00 pm causes you to be ill the next day

Answer 1

Please don't hesitate to give a "thumbs up " for the answer, in case you're satisfied with it.

I will give 2 examples of lurking variable:

1.

So, lets say there was a variable: Number of hours worked after 6 pm. If it were high then you would have late lunch (i.e. 9 pm). Also, since you worked more you fell ill the next day as you were weak because your body stressed it out on the day you worked more.

So, a lurking variable in this case is : Number of hours worked post 6 pm ( extra-time)

2. Lets say there are 2 group of people, people with bad eating habits, and another group with good eating habits.

The bad eating habits people eat late, and eat unhygienic. The good eating habits people eat early, and eat hygienic. The 1st group fall ill and second doesn't. This means that the lurking variable is the factor: "whether the person had bad or good eating habits". Here illness is caused not due to eating food post 9 am , but due to eating unhygienic food due to bad eating habits