Exercise #2: How to Read a Scientific Paper

Learning Objectives

• Distinguish between primary and secondary sources.
• Explore the layout of a scientific paper.
• Read a scientific paper effectively.
• Extract pertinent information from dense and difficult material.
• Summarize, discuss and critique a scientific paper

Summary

This exercise familiarizes students with using primary sources in research. You will learn about the difference between primary and secondary sources, and why reading primary sources is important. You will learn about the organization and layout of a scientific article. You will learn how to read an article critically and how to summarize the main points of an article. This exercise is specifically aimed at reading a primary article on a GCM. You are asked to read Jeong et al. (2011) and answer questions about each section of the article. You are asked to summarize the main points of the article and praise and criticize several points of the article.

References

Exercise

This exercise will focus on reading an article about a GCM. Remember, what you learn from this exercise about how to read a scientific research article can be applied to any research article.

Reading a scientific research article is different than reading a textbook. Textbooks distill information from the scientific literature and present it in a summary. A scientific research article is a primary source; it provides original information on how data was gathered analyzed in order to reach a conclusion about what knowledge can be gained from the study. A textbook is a secondary source. It provides an interpretation of the original material and usually includes commentary on the strengths or weaknesses of the primary source. When reading a scientific research article, it will be up to you, the reader, to interpret the information presented, and to determine its strengths and weaknesses.

It might seem like reading a textbook is an easier way to learn about new ideas because there is less work for you to do. The author of the textbook has read the primary source, distilled the main points, and provided a commentary on the information for you. But reading the primary source for yourself is essential to furthering your education. As a college student you are being trained to think critically. Critical thinking refers to higher order thinking, and questioning assumptions. Thinking critically entails evaluating information and making decisions about the merits or detriments of that information. When you read a text book, the author of the book has done the critical thinking for you, and you are learning about the author’s conclusions and interpretations. When you read a scientific research article, you can see the original information and evaluate it yourself. This will allow you to understand the information on a much deeper level, and will help you form your own opinion about the world around you.

How is a scientific research article formatted?
Most articles follow a standard format. Understanding that format can help you focus in on the information you are searching for, and can help you understand what you are reading.

Title: A short, succinct and all-encompassing statement of what the paper is about.

Abstract: A summary of the paper, highlighting key points from the methods, results and discussion. The abstract begins with a statement of why the research was done and why the results are significant. Abstracts can be dense and difficult to read because the entire paper must be summarized clearly in only about 200 words. Never cite an article after having read only the abstract! The authors’ interpretation of the research presented in the abstract may not be the same as yours after reading the full paper.

Introduction: Familiarizes the reader with past work that was done, why it was important and what gaps in knowledge it left. Explains what the author did and why it is important.

Materials and Methods: How the author did the research. (note: this section may go by many names. “Methods” is most common but in the paper we are using this section is called “Model and Experiment”).

Results: Details what the data showed. Does not include any commentary on what the results mean. This is the what of the paper.

Discussion and Conclusions: This is the section in which the author describes what they think the data means. The author explains why the data show what they show, and how this relates to the objectives of the study. This is the why of the paper.

For this exercise you will be reading the article entitled, Impact of vegetation feedback on the temperature and its diurnal range over the Northern Hemisphere during summer in a 2 X CO₂ climate. This exercise will lead you through each section of the paper and help you discover what kind of information is in each of these sections.

Keep in mind that you probably will not understand everything in this paper. Scientific papers are written by scientists, for other scientists in their field. The author is writing with the expectation that the reader has a strong background in the topic. In this case, you are not a researcher working with climate models, so you should not expect to understand everything in this paper. Nonetheless, as an educated student, you can filter through the paper and pull out the most important information.
1) Title: You need to understand all the key words in the title. If you can’t find them in the paper, search other resources for a definition.

a. What do you expect to learn from this paper?
b. What is vegetation feedback?
c. What is a diurnal temperature range?

a. Where are the authors from?
b. What kind of institutions do they work at? (schools, private industry, government agencies, etc)
c. Why do you think there are 5 authors?
d. What are the benefits of multiple authors from different institutions working together?

a. In non technical terms, what is the main point of this article? (How would you explain the point of the article to your friend or family?)
b. What topics do you hope to learn more about from the article?

a. What larger topic(s) does this study add knowledge to?
b. What new information does this paper present?
c. Why is it important for climate predictions to include daily temperature extremes as well as mean temperature?
d. In the past, what submodels were used in GCMs to predict DTR?
e. What does this study do, that previous studies did not?

a. What GCM does this study use?
b. Where can you find more information about this GCM?
c. What submodels are coupled to simulate global climate? What do the submodels calculate?
d. What land cover types does the GCM use as inputs?
e. Is this GCM the first of its kind or does it build on a previous version?
f. What variables go into the model?
g. What output does the GCM give (what does it simulate)?
h. Is the output of the GCM accurate? How is this tested?
i. Why is this model different than others and why is it important?
j. What simulations were preformed with the model?
k. How many years into the future was the model used to predict climate? Why was that time period used?

a. What does figure 1 show? What plant type will show the most change in distribution under doubled CO2 conditions?
b. How can the researchers be sure the model is working correctly?
c. What does the model predict will happen under increased CO₂ to habitats in Alaska, Canada and Eurasia?
d. What does figure 3 show? What conclusions can you draw from looking at this figure?

a. In brief and general terms, why is this model unique?
b. Why is this model needed?
c. What weaknesses or biases in this study do the authors point out?
d. What future work do the authors suggest?

a. What is the main conclusion of this paper?
Now that you have read the entire article and pulled out the most important pieces of information, it is important that you summarize the article, and include your own thoughts on the points the article made. This step is essential. As a college student, you will find yourself reading many articles throughout your education. Keeping summaries of the papers you have read will help you use them effectively in the papers you will write. Your summary and personal critique of the article will help you decide quickly if the article is useful for any papers you may be asked to write in the future.

Technological Note: If you are interested in keeping an electronic library of scientific papers you have read or are interested in reading, you can visit Mendeley.com to download a free PDF organizer. With this program you can highlight articles and make typed notes that are attached to the PDF. As you continue in your educational career, keeping track of previous research and papers read can save you time and help you to build on previous knowledge for future research.