Discuss how to discuss in a paper / Feb 15th

To define what belongs in the results vs. what belongs in the discussion. The results is the report in miniature. This is the data. Examples phrases: …the analysis revealed…does not rule out…the test indicates…seems likely…in contrast…it is highly probable…

Results have:

· Pure numbers—raw data/facts (1,2,5,3,7) and statistical conclusions (mean=4, std error, p-value, etc.). This info goes into the tables (requires column and row headings, title (above the table). Example, “No difference was found between the 2 means (p-0.48, t-test).”

· Graphs illustrate raw data and statistical results (use captions below the figure).

· Text (report comparisons) describes but doesn’t explain data and stats.

Results don’t have:

· Comparisons to other studies—their results aren’t influenced by other researcher’s data in their field

· Context – move any context to the discussion area.

· Background info—mostly the background is inferred from the graphs

A key part in the final paper grade is making sure that information in each section is appropriate (don’t worry about the transitions between sections).

Discussion has:

· Context and no data – it’s all words explaining and interpreting

· Is subjective (as opposed to objective results)

· Conclusion: what your rejection/acceptance of your hypothesis means in the real world. Extrapolate from the specific results of your experiment to a more general question.

· Lots of reference to other scientists work looking for broader implications even if those implications weren’t tested explicitly.

· Building our case for our argument.

· No direct quotes (will deduct 5 points)

· Put in controversies to your results.

· Are you satisfied with the experiment? Admit what you might have been a better approach. What other experiments do you want to do?

Revised text on report:

Summary and conclusion

The testing performed to determine the mechanism of shell thickening indicated that there was no significant difference in shell length growth between the two groups of snails. This is probably the case because the testing was done in close proximity. Other studies have shown that growth patterns in similar levels of genetic variation exist across latitudes (Trussel, 2000)⁴. Surveys of phenotypic variation in 25 Littorina obtusata populations across an approximately 400-km latitudinal gradient in the Gulf of Maine revealed pronounced differences. The shells of snails from northern habitats weighed less and were thinner and weaker in compression than those from southern habitats. In contrast, body size (as measured by soft tissue mass) followed an opposite pattern; northern snails weighed more than southern snails (11–24% for shell mass, 13–17% for shell thickness after 115 days; Trussell). These results are consistent with the expected effects of reduced water temperature on growth (Atkinson, 1994). In addition, increased developmental sensitivity to differences in water temperature may have evolved in northern populations due to the comparably shorter growing season (Conover and Present 1990).

Future experiments that address the role of total body mass induced by food varieties and predator attacks may also help to clarify the mechanisms underlying geographic variation in shell form and body mass. There is a good probability that with studies conducted in locations further apart, and with the use of these variables snail total mass growth will be further exposed.