Questions: Ayomide is reading a recent article with the headline "School lunches make kids overweight." The article cites a study comparing children at two schools. At the school with the lower obesity rate, only a few children eat school lunch. The other school has a greater percentage of obese children, and most of these children eat school lunch. The article doesn't mention that the school with the higher obesity rate is in an area where most people are below the poverty line, nor does it mention that poverty can be a major factor in obesity. What validity is threatened by the potential confound of poverty?

The answer is internal validity.

Explanation:

• Internal Validity: This is concerned with whether a causal relationship can be established between variables. In this case, the potential confound of poverty threatens internal validity because it suggests that factors other than school lunches (such as socioeconomic status) might be influencing obesity rates.

• External Validity: This refers to the generalizability of the study's findings to other settings or populations. The confound of poverty does not directly affect external validity.

• Construct Validity: This involves whether the study accurately measures the concepts it intends to measure. The issue here is not about measurement but about confounding variables.

• Statistical Validity: This relates to the appropriateness of the statistical methods used and the conclusions drawn from them. The confound of poverty is more about the study design than statistical analysis.