1b. Model. What hypothesis do Grandjean et al. (1998) test? (one sentence answer)

1c. Data. What data do Grandjean et al. (1998) gather to test their hypothesis? (one or two sentence answer)

1d. Evaluation. Do the data that Grandjean et al. (1998) gathered support their hypotheis? What are the major limitations of any conclusions that Grandjean et al. (1998) reach? (one paragraph answer)

Partial answer: The data gathered by Grandjean et al. (1998) do support the hypothesis that exposure to low levels of methylmercury during pregnancy reduces cognitive ability. The major uncertainty surrounding this conclusion is the potential role of confounders. To complete the answer, identify the major confounders, and briefly explain how they create uncertainty.

1e. Revision. How does the Grandjean et al. (1998) study improve on previous studies of those exposed to mercury in poisoning incidents in Japan and Iraq? How might a study done in the future improve on the Grandjean et al. (1998) analysis? (one paragraph answer)

Answer sketch. The Japan and Iraq studies investigated those exposed to very high levels of mercury. At present, we know little about the molecular mode of action of mercury.