If the researchers in the observational study found strong results, why might we be skeptical that they were caused by the diets implemented?The researchers didn't study the lurking variables.We can never be 100% certain of a claim of causation based on an observational study.The Hawthorne Effect is biasing the data.The response variable is too subjective.

During the Hawthorne Studies, researchers were baffled when went up regardless of changed environmental conditions.

Consider the following causal argument:Dave: Eating a paleo diet (a diet high in protein and unprocessed foods) has massive health benefits. And I’m not just making this up! I did some research. I chatted with 10 different people who are on the paleo diet, and all of them looked really fit and healthy.Which one of the following claims is true of Dave’s argument:Group of answer choicesThe people who are on the paleo diet are the test group, and Dave is the control group.The people who are on the paleo diet are the test group, and the people who are not on the paleo diet are the control group.Dave does not set up a test group and a control group in this argument.The people who are on the paleo diet are the control group, and the people who are not on the paleo diet are the test group.

What did the researchers, who identified the Hawthorne effect, see as evidence that employee performance was influenced by something other than the physical work conditions?Group of answer choicesManagers who told their subordinates they were under observation received more complaints than other managers.Employees who knew they were being observed called in sick more often than employees who did not know they were being observed.Any change in a variable, such as lighting levels, led to an improvement in productivity; this was true even when the change was negative, such as a return to poor lighting.Employees who believed they were under observation performed the same as employees who did not believe they were under observation.

Which one of the following is an advantage of an observational study when compared to an experimental study? Lurking variables are not a problem. The treatments studied may be unethical when used in experiments. Randomization is less important because researchers are observing things “as they happen.” The treatment can be controlled by the researchers.

The first group of researchers find that all the participants who agreed to be on one of the diet plans had fewer health problems and lived longer than the participants in the control group.  They send these results into a journal for publication but the reviewer becomes worried that, because the participants were allowed to choose which treatment group they would be in, there could be cause for concern. The reviewer asked the researchers to control for exercise in their study by comparing participants who had similar lifestyles but different diets. Researchers discovered that all of the more active participants chose to be on the trendy diets and all of the less active participants chose to be on the traditional American diet. Because this was the case it is very hard for researchers to determine if the diets were causing the positive health outcomes or if the more active lifestyles were causing the positive health outcomes.Lifestyle could therefore be a: Hint, displayed belowPositive OutcomeLurking VariableExplanatory VariableResponse Variable