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IS 1115 TWP: A Library Guide: Evaluating information sources. How Good Is the Evidence?

Information sources establish your credibility. Use the most credible sources that are appropriate for persuading your audience.

Empirical Question


  • theoretical
  • not based on evidence               



  • pertaining to or based on experience.
  • pertaining to, derived from,
    • or testable by observations made using
      the physical senses or using instruments which extend the senses.
  • verifiable by means of scientific experimentation.
  • empirical is always a primary source

Image result for american journal of public health cover

Seward, M. W., Block, J. P., & Chatterjee, A. (2016). A Traffic-Light label intervention and dietary choices in college cafeterias. American Journal of Public Health, 106(10), 1808-1814. doi:10.2105/AJPH.2016.303301


Objectives. To examine whether traffic-light labeling and choice architecture interventions improved dietary choices among students at a northeastern US university. Methods. In 6 cafeterias at Harvard University, in Cambridge, Massachusetts, we implemented a 7-week intervention including traffic-light labeling (red: least nutrient rich; yellow: nutrient neutral; green: most nutrient rich), choice architecture (how choices are presented to consumers), and "healthy-plate" tray stickers. During the 2014-2015 academic year, 2 cafeterias received all interventions, 2 received choice architecture only, and 2 were controls. We analyzed sales for 6 weeks before and 7 weeks during interventions. Using interrupted time-series analyses, we measured changes in red, yellow, and green items served. We collected 1329 surveys to capture perceptions of labeling. Results. Among 2.6 million portions served throughout the study, we found no significant changes in red (-0.8% change/week; P = .2) or green (+1.1% change/week; P = .4) items served at intervention sites compared with controls. In surveys, 58% of students reported using traffic-light labels at least a few times per week, and 73% wanted them to continue. Conclusions. Although many students reported using traffic-light labels regularly and wanted interventions to continue, cafeteria interventions did not demonstrate clear improvements in dietary quality.
Is this article from AJPH...
Scholary: 16 votes (76.19%)
Non-Scholarly: 5 votes (23.81%)
Total Votes: 21
Is this article from AJPH...
Primary: 15 votes (71.43%)
Secondary: 6 votes (28.57%)
Total Votes: 21
Is this article from AJPH....
Empirical?: 15 votes (75%)
Non-empirical?: 5 votes (25%)
Total Votes: 20
Would you use it to support an argument?
Yes: 10 votes (47.62%)
No: 1 votes (4.76%)
Maybe: 10 votes (47.62%)
Total Votes: 21