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Michigan State University

Biosystems & Agricultural Engineering: Information Evaluation / Primary Sources

This guide provides key resources for researching biosystems and agricultural engineering topics, including bioenergy, food safety and quality sensors, water quality, sustainable ecosystems, resource conservation, and biosensors.

Information Evaluation

Here are some questions to guide you through the process of critical evaluation of information sources:


  • Is the document related to your on topic?
  • Is the information at appropriate depth or level for your assignment?


  • Is the source a scholarly or popular publication? And is the publisher reputable in this discipline?
  • Is the author a recognized authority in this field of study? What are their credentials? (And are their credentials related to the subject matter?)
  • Do other authors quote from this author's works?
  • Is there a means of contacting the author?


  • When was the document written? (Look for a publication, copyright, or “last updated” date.)
  • Is it recent enough to be relevant to your topic or discipline? Sometimes you are required to use recently published material; sometimes you must use historical documents.


  • Does the author provide sources for statistical information?
  • Is the data from a valid study (that utilized accepted methodologies for the discipline)?


  • Analyze the author's argument, the assumptions made, the evidence or data gathered, and the interpretation of the data.
  • Are there any flaws in the author's logic?
  • Does the author consider alternate interpretations of the evidence?
  • If you discovered that the author ignored other interpretations, is the author attempting to deceive or manipulate readers?


  • Does the author refer to relevant information or data that was available at the time the work was published?
  • Or, does the author use out-of-date information; or ignore information or data that was available at the time?
  • Did the author consider all aspects relevant to the topic?


  • Does the author state any bias?
  • If you discovered any omissions in the coverage of the topic, did this reveal a bias or prejudice?
  • Is the author selling something? Do they have a corporate sponsor?

TIP:  Considerable information is now available online; however, because the Internet is relatively anonymous it is critical that you evaluate your online sources carefully. "Evaluating Web Pages” is an excellent guide to this topic produced by the UC Berkley Library.

Primary Sources

What Are Primary Sources

Primary sources are the direct, uninterpreted records of the subject of your research project. As such, a primary source can be almost anything, depending on the subject and purpose of your research. Be creative in thinking of possible relevant primary sources of information on your topic.

Why Use Primary Sources?

  • A primary source is as close as you can get to the event, person, phenomenon, or other subject of your research.
  • A primary source on its own is likely only a snippet or snapshot of the full picture; thus it is often difficult to interpret on its own.
  • Reference sources and secondary analyses give you a framework for interpreting primary sources. T
  • The real work of research is examining primary sources to test the interpretations, analyses, and views you find in reference and secondary sources.
  • Use primary sources to find evidence that challenges these interpretations, or evidence in favor of one scholar's interpretation over that of another; then posit an interpretation of your own, and look for more primary sources for evidence to confirm or refute your thesis.
  • When you present your conclusions, you will have produced another secondary source to aid others in their research.

Types of Primary Sources:

  • Lab reports: experiments, observations, etc.
  • Historical documents: official papers, maps, treaties, etc.
  • First –person accounts: diaries, memoirs, letters, interviews, speeches, etc.
  • Recordings: audio, video, photographic, etc.
  • Artifacts: manufactured items such as clothing, furniture, tools, buildings
  • Newspapers: some types of articles
  • Government publications: statistics, court reports, etc.
  • Internet resources: see, especially, digitized versions of historical documents
  • Manuscript collections: collected writings, notes, letters, and other unpublished works
  • Books: extensive and detailed discussions of a particular topic or set of topics, written by the scholars and researchers who came up with the ideas or discovered the findings