Coverage error

All colored circles are included in the target population. Green and Orange colored circles are included in the sample frame. Green colored circles are a randomly generated sample from the sample frame.  The sample frame includes overcoverage because John and Jack are the same person, but he is included more than once in the sample frame.  The sample frame includes undercoverage because not all of the target population is included in the sample frame.

Coverage error is a type of non-sampling error[1] that occurs when there is not a one-to-one correspondence between the target population and the sampling frame from which a sample is drawn.[2] This can bias estimates calculated using survey data.[3] For example, a researcher may wish to study the opinions of registered voters (target population) by calling residences listed in a telephone directory (sampling frame). Undercoverage may occur if not all voters are listed in the phone directory. Overcoverage could occur if some voters have more than one listed phone number. Bias could also occur if some phone numbers listed in the directory do not belong to registered voters.[4] In this example, undercoverage, overcoverage, and bias due to inclusion of unregistered voters in the sampling frame are examples of coverage error.

  1. ^ Salant, Priscilla, and Don A. Dillman. "How to Conduct your own Survey: Leading professional give you proven techniques for getting reliable results." (1995)
  2. ^ Fisheries, NOAA (2019-02-21). "Survey Statistics Overview | NOAA Fisheries". www.fisheries.noaa.gov. Retrieved 2019-02-24.
  3. ^ Scheaffer, Richard L. 1996. Section 5 of Teaching Survey Sampling, by Ronald S. Fecso, William D. Kalsbeek, Sharon L. Lohr, Richard L. Scheaffer, Fritz J. Scheuren, Elizabeth A. Stasny. The American Statistician 50:4 (Nov. 1996), pp 335–337. (on jstor)
  4. ^ Scheaffer, Richard L. (2012). Elementary survey sampling (7th, student ed.). Boston, MA: Brooks/Cole. ISBN 978-0840053619. OCLC 732960076.