Data Limitations

Limitations of the Data

As with any large dataset, there are certain limitations to what data are available. It is important to keep these limitations in mind, especially when comparing programs and/or institutions.

Limitations include:

  • The census data only includes individuals who earned wages in the U.S. The data do not include individuals working outside the U.S.; self-employed individuals not reporting enough wage earnings to meet the minimum wage threshold; and individuals who are not currently working.
  • When looking at the industries where graduates are employed, we do not know what type of work the graduate may be doing. For example, a graduate with a degree in marketing who works for Iowa State would be classified in the educational services industry.
  • Data are left blank or are suppressed if the number of individuals in a certain grouping is too small.
  • Data are not necessarily recent; five-year data is only available at the 2010-2012 cohort or earlier for bachelor’s graduates, and the 2006-2010 cohort for masters and doctoral programs.
  • Degrees are based on Classification of Instructional Programs (CIP) codes, which do not always match the names of our academic majors. The Institutional Research website will provide documentation that  shows the connection between current majors and the CIP code names used on the Census Bureau website.
    • For masters and doctoral programs, data is only available at the 2-digit CIP code “general” program specificity (e.g., engineering, as opposed to aerospace engineering).
    • Since data goes back to 2001, there are majors included that are no longer offered at Iowa State in the data set. Similarly, newer majors will not be represented yet.
  • Employment industries are based on first two digits of the NAICS coding structure.
  • The geographic regions are based on U.S. Census definitions. Iowa is in the West North Central Division of the Midwest Region.
  • When comparing across majors or institutions, the data can be skewed by where graduates live. If most apparel merchandising graduates move to New York City, for example, their earnings will reflect a higher cost of living.
  • Looking at salary data, it will generally be most helpful to focus on the most recent cohort of graduates, who graduated in 2016-2018, for first-year earnings data; the 2013-2015 cohort for 5-year data; and the 2007-2009 cohort for 10-year data.