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Statistics & Data

Evaluating Data Sources

NEVER accept a statistic, data table, or chart without assessing its credibility!

ALWAYS evaluate how this information was derived by:

  • Checking for a citation
  • Evaluating the original source

Statistics are very easy to manipulate or misinterpret due to the complex nature of gathering data. Asking the following questions will help you evaluate the quality of the data/statistics.

How to Evaluate Data and Statistics

Find the Data Documentation (if available), usually in the form of a User Guide, Codebook, and/or Questionnaire to help you understand and evaluate the data.


  • Who collected the data? Are they an individual or organization?
    • If an individual, are they an expert in this subject area? What organizations are they associated with?
  • What are the credentials of the data collector/producer?
  • How widely known/cited is the data collector/producer? Who uses the data?
  • When were the data collected?

Purpose and Objectivity

  • Why were the data collected?
  • Who funded or sponsored the data collection/production?
  • Who is the intended audience for the data?

Methodology and Documentation

  • How are the data collected?
  • If a survey, what is the sample size? How was the population sampled? Who is included/excluded from the survey? What was the response rate?
  • Can you find any documentation on the data? How well are the data documented? What questions were asked? Are they leading questions?

Consistency and Verification

  • Can the data be verified?
  • Do other valid sources provide similar numbers?

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