A primary source in the sciences is a report on the results of an experiment, intervention, or trial by the person or group who performed it, usually published as an article in science and medical journals. Primary scientific articles contain high-level vocabulary and will usually present original data, often displayed in tables or charts. In contrast, secondary sources in the sciences, which are often referred to as review articles, will synthesize, interpret, or analyze the findings of a scientist or group of scientists studying the same thing in an attempt to summarize the current state of knowledge on a topic.
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Elements of a Primary Scientific Source
The authors of a scientific primary source report the results of their own research, although they may refer to someone else’s work in the body of the paper to illustrate points they are trying to validate, replicate, question, or disprove. Most scientific journals that are peer-reviewed are likely to contain primary literature. Peer-review means that a panel of experts will review all articles submitted for publication before they are accepted by the journal.
In a primary research article, you will typically see many or all of the following elements clearly presented as shown:
- An abstract/summary of the research.
- Author’s affiliation.
- Introduction with a hypothesis or thesis statement that often includes a review of other literature pertaining to the experiment. A review of literature section may be under a separate heading.
- Materials, equipment, and methods used to conduct the experiment. In some articles, materials and methods may be under separate headings.
- Results of the experiment that may include data in various forms, including tables, charts, graphs, figures, images, and photographs.
- Discussion of the results.
- Conclusion.
- References/Bibliography.
Research databases provide clues that you are looking at a primary science article. As you examine the record of an article in a database, you will start to notice clues about the article type, as with the example below.
The journal title itself may offer a hint about the nature of the materials published within it. While any science journal may routinely publish a variety of articles types including opinions and reviews, in this case, the word "investigation" in The Journal of Clinical Investigation implies that primary articles are likely to appear in the journal. In addition, the title of the article provides a conclusion to what was likely a working hypothesis.
Liszt, K. I., Wang, Q., Farhadipour, M., Segers, A., Thijs, T., Nys, L., Deleus, E., Van der Schueren, B., Gerner, C., Neuditschko, B., Ceulemans, L. J., Lannoo, M., Tack, J., & Depoortere, I. (2022). Human intestinal bitter taste receptors regulate innate immune responses and metabolic regulators in obesity. The Journal of Clinical Investigation, 132(3), e144828. https://doi.org/10.1172/JCI144828
The abstract or summary provided by the database also provides offers clues as to the nature of the article (highlighted below):
- What is already known is stated: "Bitter taste receptors..."
- A new intervention is proposed: “We investigated...”
- Intervention/hypothesis is described: "potential to trigger"
- Conclusion is summarized: “We found...”
- Scientific terminology: TAS2Rs, human jejunal crypts, proteomics
- Methods and results briefly described
- Ideas for follow up experiments: "may be valuable markers to predict therapeutic response"
Abstract: Bitter taste receptors (taste 2 receptors, TAS2Rs) serve as warning sensors in the lingual system against the ingestion of potentially poisonous food. Here, we investigated the functional role of TAS2Rs in the human gut and focused on their potential to trigger an additional host defense pathway in the intestine. Human jejunal crypts, especially those from individuals with obesity, responded to bitter agonists by inducing the release of antimicrobial peptides (α-defensin 5 and regenerating islet–derived protein 3 α [REG3A]) but also regulated the expression of other innate immune factors (mucins, chemokines) that affected E. coli growth. We found that the effect of aloin on E. coli growth and on the release of the mucus glycoprotein CLCA1, identified via proteomics, was affected by TAS2R43 deletion polymorphisms and thus confirmed a role for TAS2R43. RNA-Seq revealed that denatonium benzoate induced an NRF2-mediated nutrient stress response and an unfolded protein response that increased the expression of the mitokine GDF15 but also ADM2 and LDLR, genes that are involved in anorectic signaling and lipid homeostasis. In conclusion, TAS2Rs in the intestine constitute a promising target for treating diseases that involve disturbances in the innate immune system and body weight control. TAS2R polymorphisms may be valuable genetic markers to predict therapeutic responses.
Keywords: Gastroenterology, Metabolism
Keywords: G protein—coupled receptors, Innate immunity, Obesity
Elements of Secondary Scientific Source
Secondary sources in the sciences are often referred to as review articles. Review articles synthesize, interpret, or analyze the findings of a scientist or group of scientists studying the same thing in an attempt to summarize the current state of knowledge on a topic. They may discuss the ways in which various researchers' work is related or consider the implications of the research, and pose broad or abstract questions about a field of study. They look more like traditional journal articles, not necessarily laid out in a linear way.
Another type of secondary source in the sciences is a meta-analysis. A meta-analysis examines data from a number of independent scientific studies on the same subject, or that used a similar hypothesis. The point of a meta-analysis is to determine overall trends and figure out whether similar interventions have similar success rates and similar degrees of error. Looking at similar interventions from various independent sources can help the scientific community determine whether to try marketing a new product or process, influence government policy, or change medical policy and treatment.
Secondary sources are useful in the pursuit of primary sources. A review or a meta-analysis on the topic of interest will contain a lengthy biography of all the primary studies included in the review or analysis. You can then use those citations to find out if UMass Global has access to the primary studies. Using those bibliographies can save you a lot of time when searching for primary studies.
However, even if you can use a review or meta-analysis directly, you should always consult the primary article(s) yourself. It is important for you to have a complete understanding of the original studies so that you can draw your own conclusions about the their methods, efficacy, and relationship to similar studies.
Here is an example of a secondary science article:
The title and abstract provide clues as to the nature of the article (highlighted below):
- The phrase "systematic review of literature" is in the article title
- Relative lack of scientific terminology in the abstract
- Goal of article is described: "This systematic review was aimed to establish...."
A. A. T., H., Gillani, S. W., A. A. A., M., & Gulam, S. M. (2020). Safety and Efficacy Evaluation of Lipid Lowering Agents Use among Diabetes Patients: A Systematic Review of Literature. International Medical Journal, 27(6), 681–685.
Abstract: Objective: This systematic review was aimed to establish the safety and efficacy outcomes of statins in diabetes mellitus. Methods: Literature review and identification and screening were done according to PRISMA guidelines. Data collected from various articles like PUBMED, WILEY LIBRARY, SCIENCE DIRECT, LANCET, AAPS, SCOPUS, etc. Results: statins have proved the most common safe and efficient medications to treat familial hyperlipidemia besides their minimal side effects. Various risk factors have been linked to statins and new onset diabetes (NOD). The study reveals the remarkable correlation between diabetes type 2, and statins showed significant dose related and duration mild to moderate risk of NOD. Meta-analyses of randomized controlled trials (RCTs) reveals a mild to moderate risk of NOD with statin therapy, while observational studies indicate a more significant association between statins and onset of diabetes. Besides the lipid lowering positive effects of statins in CVD and FH patients, high potency, chronic administration of some individual classes statins like atorvastatin, simvastatin progresses the new onset diabetes in specific individuals with underlying risk factors that leads to new onset diabetes. Conclusion: In order to provide conclusiveness between the positive and negative effects of statins, further studies must conduct on large population with different ethnic groups, and hyperglycemic effects of statins can overcome by lifestyle changes, regular exercise, and diet.
How to Find Primary Science Sources Using Library Databases
The UMass Global Lbrary's databases are the best place to start your search for primary sources in the sciences. If you know which journals you want to read, you can see if UMass Global has access to them using the A-Z Journals List.
If you are not sure which journals you should be reading, you can select subject-specific databases to find sources in the following areas:
- Biology
- Allied Health Care
- Nursing
- Psychology
- and other science fields
The library's Advanced Search engine can also be used to look for scientific information. Review the Advanced Search guide for more database search techniques. When searching, look for articles that describe the subject, methodology, results, and implications of the research (usually found under the Discussion subheading). These sections are normally included in a primary research article.
Some subject-specific databases also have advanced search screens:
Depending on the database, advanced search screens may include many different filters that you can use to search for specific methodologies, elements, and features including:
- Type of article
- Type of query
- Whether the study was a controlled trial
- Geography of study
- Sex of participants
- Age group of participants
- Human or animal experiment
- Further breakdown of article type (review, meta-analysis, etc.)
- Images, including charts, graphs, diagrams, and other data
The image below is an advanced search screen from a ProQuest nursing database. Other providers may look different but will have similar options.
Click image to enlarge.
If you need help locating primary and secondary scientific articles, submit your question using the form on the Ask a Librarian page or schedule a research appointment. If you are new to research or need a refresher, visit the Getting Started with Research guide.
How to Find Primary Scientific Sources from Free Resources
Primary scientific sources can be found on the open web as well as in the library’s databases. These sources are typically provided by college and university websites, institutional repositories, open access publishers, and open access databases.
To find primary scientific sources, use Google or another browser to search for keywords that best describe your topic. Depending on what you need, you may include terms such as “experiment”, “trial”, “clinical trial”, “study”, or “investigation” to refine your search. Add “open access” or "open data" to the search to return results that include free, openly available material. For example:
Below is a select list of websites that provide access to primary scientific sources. Similar to library databases, many of the websites have options for limiting your search based on the criteria you enter (such as article title, subject, or author) and other advanced search features.
