How to write papers: “Materials and Methods” “Results and Discussion”

How to write papers:“Materials and Methods” “Results and Discussion” Changying Li May 2, 2012

Two golden rules • Write a little bit everyday (no more than 2h/day; but daily) • Dirty writing first and then clean the mess (separate drafting from revision)

Purpose of a paper • Scientific papers are for sharing your own original research work with other scientists or for reviewing the research conducted by others. • papers must aim to inform, not impress. They must be highly readable — that is, clear, accurate, and concise. They are more likely to be cited by other scientists if they are helpful rather than cryptic (obscure) or self-centered.

Four components • Introduction • Materials and Methods • Results and Discussion • Conclusion

M&M • Other scientists working in the field would be able to replicate the work. • Although you can cite, it is important to include enough information so that readers are able to evaluate the work being presented without having to refer to another publication. • Often the company (including city and state) that manufactures a particular reagent is specified to reduce any ambiguity about what was used; likewise, the model number for a piece of equipment is often indicated.

M&M • Explain the choice you made in your experiment; what justifies using a given method? What is special, unexpected in your approach • Begin with a topic sentence • Use a table or schematic diagram if possible • Past tense • Passive voice

Example 1: MM • Nature article

Example 2: MM • The imaging unit consists of a zoom lens (F/1.4, f = 17.53 mm) (XNP 14/17-0503B, Schneider Optics, Hauppage, New York, USA), a 14-bit CCD camera with a 1392 x 1040 resolution (ICL-B1410, Imperx Inc., Boca Raton, Florida, USA), and a prism-grating-prism imaging spectrograph (ImSpector V10E, Specim, Oulu, Finland). The CCD camera is in a 1.7 cm (2/3’’) format with a square pixel size of 6.45 μm. The maximum quantum efficiency of the CCD camera is over 90% at 650 nm and 20% at 1000 nm. The camera exposure time was 15.2 ms. A frame grabber with standard Camera Link protocol (Model NI PCI-1426, National Instruments, Austin, Texas, USA) was used to acquire monochromatic images with 65 frames per second sampling rate. The computer used for image acquisition and analysis was a Dell Optiplex PC with Duo Core CPU (3 GHz and 2 GHz) and a random access memory of 3.25 GB (Dell Inc., Austin, Texas, USA). The spectrograph has a nominal spectral resolution of 2.8 nm. Therefore, a 4 x binning was implemented in the spectral dimension of the CCD camera to make the spectral resolution of the CCD camera (2.3 nm/pixel) match with that of the spectrograph. The final hyperspectral image had 1392 pixels in the spatial dimension and 260 pixels in the spectral dimension.

R&D • This section is written around the data (figures, tables) • Convey the message first with a topic sentence • Don’t repeat the information already in tables and figures: reveal the trend, pattern that are invisible or not easy to see • Compare with existing literature • Separate R from D?

Results • Let the data speak for themselves • Authors’ results should be in past tense, and general statements in present tense. • This usually is the shortest section of a manuscript. • Common mistake: repeat what is in the tables/figures: example.

Discussion • Two purposes: • Interpretation of the data • Relate these findings to what other investigators have found (similar to literature review…).

Discussion • Try to present principles, relationships, and generalizations shown by results. • Point out exceptions or any lack of correlation and define unsettled points. Don’t cover up. • Show how your results and interpretations agree with previously published work. • Theoretical implications and possible practical applications

Examples: good and bad

References • R. Day. How to write and publish a scientific paper. • Beth A. Fischer and Michael J. Zigmond. Components of a research article. • Nature Education. How to write papers.

Good luck with your paper writing!

How to write papers: “Materials and Methods” “Results and Discussion”