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Biology: Understanding & Evaluating Scientific Research

The Scientific Process

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understanding and evaluating scientific sources

 

The Scientific Process

Science often gets a bad rap for "changing its story"-- one year, coffee is bad for you, and the next it is good for you. It's not that science is indecisive -- rather, new evidence is always being discovered or understood in new ways. Science is always changing in a complex, step-by-step process.  Having a basic understanding of how science works will help you understand and assess scientific sources for your coursework and in your day to day life. 

Things to know that will help you understand scientific research:

Check out UC Berkley's Understanding Science Website for more information about the process of science and misconceptions about science. 

And check out Science is a Process on the Scholarly Kitchen with a fun video featuring Adam Savage from Mythbusters.

The Scientific Method

You have probably encountered the scientific method at some point in school.  It outlines the general steps by which the scientific process advances.

  • An observation is made and/or a question asked
  • A hypothesis is formulated to explain the observation/answer the question
  • An experiment is designed to test the hypothesis
  • Data is collected and analyzed
  • Reason and interpretation of the data are used to draw conclusions
  • The experiment must be repeatable, i.e. able to be tested by other scientists
  • As several researchers/experiments examine a particular observation/question, conclusions may change as new evidence accumulates

Diagram of the steps of the scientific process: Observation, question, hypothesis, experiment, analysis, conclusion

If evidence doesn't support the hypothesis, then the hypothesis is discarded, not the evidence.  A new explanation for the evidence must be tested.  

 

Interpreting Research

Identify the Question

  • When you're reading an article, pinpoint the question(s) the author(s) are trying to answer.  The study objectives should be clearly stated.

Types of Studies

  • Observational 

    • Looking for patterns in a population/set of data/system

    • Researchers are not manipulating or changing anything - just observing 

    • Often done as a survey

Ex.  Palmer, W. L., Bottle, A., & Aylin, P. (2015). Association between day of delivery and obstetric outcomes: Observational study. BMJ : British Medical Journal (Online), 351 https://doi.org/10.1136/bmj.h5774

  • Experiment  

    • Usually has a "control" group to compare to the group receiving some sort of "treatment"

    • May be "blinded" (subjects don't know what treatment they will receive) or "double-blinded" (neither subjects nor experimenters know what treatments the subjects will receive).  Helps prevent bias from affecting results.

Ex. 

Litvin, A. G., Currey, C. J., & Wilson, L. A. (2020). Effects of Supplemental Light Source on Basil, Dill, and Parsley Growth, Morphology, Aroma, and Flavor, Journal of the American Society for Horticultural Science J. Amer. Soc. Hort. Sci., 145(1), 18-29. Retrieved Sep 24, 2020, from https://journals.ashs.org/jashs/view/journals/jashs/145/1/article-p18.xml

Batel, A., Linti, F., Scherer, M., Erdinger, L. and Braunbeck, T. (2016), Transfer of benzo[a]pyrene from microplastics to Artemia nauplii and further to zebrafish via a trophic food web experiment: CYP1A induction and visual tracking of persistent organic pollutants. Environ Toxicol Chem, 35: 1656-1666. doi:10.1002/etc.3361

Examine the Conclusions

  • Do the author(s) conclusions make sense? 
  • Do you feel that they answered the question/objectives?
  • Do the author(s) explore possible limitations or problems with the study?
  • What areas for further research were identified?  

Reading Graphs and Charts

  • Graphs are an important way for researchers to present their data in ways to help identify and understand patterns.
  • Check the x-axis (horizontal) and y-axis (vertical) labels to be sure you understand what the graph represents.
  • A common format is to have time on the x-axis and quantity of what is being measured on the y-axis.
Ex. A graph of plant growth might have time in days plotted on the x-axis and growth in inches on the y-axis.  
  • Be sure you understand the scale of the graph.  
Ex. For the plant growth graph, does each tick mark on the axis stand for an inch, a foot?  Scale can make a big difference!

xkcd: Extrapolating, by Randall Munroe

 

Beware of Pseudoscience Traffic Sign, Sign

Sometimes "theories" or ideas may be presented as "scientific," but if the ideas are not tested and evaluated using the scientific method, then they are not truly science and should be viewed with skepticism.  

URL: https://lib.pstcc.edu/biology