NCES Blog

National Center for Education Statistics

Behind the degree: Direct measures of cognitive skills or reports of highest degree earned

By Heidi Silver-Pacuilla

Categories of educational attainment – or highest degree earned – are often used in social science research as an indicator of a person’s knowledge and skills. This measure is objective and readily available, easily understood by survey respondents as well as by consumers of research and survey data, strongly tied to policies (such as those promoting high school graduation and college completion rates), and widely used in the labor market by employers. Moreover, strong connections between educational attainment and positive life outcomes, such as employment, earnings, health, and civic engagement, are well established.

Yet, this measure is an imprecise indicator of the amount of knowledge and skills an individual acquired during the years of education it took to complete the degree. It also masks variation across individuals and programs of study. In addition, adults continue to acquire skills and knowledge from a variety of sources and activities over their lifetimes after completing a degree, while on the job or through employer-sponsored training, continuing education, family and household management, hobbies and interests, etc. Adults also lose fluency with skills that are not put to regular use.

The Program for the International Assessment of Adult Competencies (PIAAC) survey[i] provides direct measures of working-age adults’ cognitive skills based on their performance on literacy, numeracy, and problem-solving tasks set in real-life contexts. Performance is reported on a scale of 1-5 for literacy and numeracy and a scale of 1-3 for problem solving. It pairs these measures with a background questionnaire that asks about the use of skills at work and in daily life, work history, and other social, behavioral, and demographic indicators.


Percentage of adults age 16 to 65 at each level of proficiency on the PIAAC literacy scale, by highest level of educational attainment: 2012Percentage of adults age 16 to 65 at each level of proficiency on the PIAAC literacy scale, by highest level of educational attainment: 2012

# Rounds to zero
NOTE: Percentages of adults age 16 to 65 by highest level of educational attainment appear in parentheses. Detail may not sum to totals because of rounding.
SOURCE: U.S. Department of Education, National Center for Education Statistics, Organization for Economic Cooperation and Development (OECD), Program for the International Assessment of Adult Competencies (PIAAC), 2012.


The direct measures of cognitive skills offer researchers the ability to study actual skills rather than only using attainment of a particular degree as a general indicator of skills, and to investigate how those assessed skills relate to behaviors and life outcomes. To illustrate how directly measured skills and educational attainment are not always aligned, we can compare direct performance to highest degrees earned. In the United States, of all adults who have attained only a high school degree, 20% performed in the lowest levels (Level 1 and Below Level 1) of literacy, while 7% of adults with an associate’s degree and 5% of those with a bachelor’s degree performed at this level. At the same time, the results showed that 6% of adults with no more than a high school diploma, 14% with only an associate’s degree, and 24% with a bachelor’s degree have very high literacy skills, at Level 4 or 5 on the same scale. See the full range of educational attainment and skill performance in literacy in the chart above.

Findings such as this can help inform policy, interventions, and communication strategies to better meet the needs of the recipients.

To read more about direct measures versus educational attainment, see Chapter 8 of the OECD Survey of Adult Skills – Reader's Companion.


[i] The PIAAC survey is coordinated internationally by the OECD. NCES implements PIAAC in the United States. Results were first released in October 2013 with data from 23 countries. It is a household survey administered by trained data collectors to a nationally-representative sample of adults, ages 16 through 65, in each country, in the official language(s), and in most cases, in respondents’ homes on a laptop computer.

In the United States, the survey was first administered in 2012 and additional results, based on an expanded sample, will be released in 2015-2016. To learn more about the U.S. administration and reporting of the survey, as well as related data tools, see https://nces.ed.gov/surveys/piaac/.  

Meeting policy needs for new data sources: Measuring work-related credentials

By Sharon Boivin

In the late 2000s, rising unemployment due to the recession led policy makers to begin asking questions about the qualifications of the American workforce, such as:

  • How many US adults have an education or training credential that is recognized by employers?
  • How many adults complete at least one year of education or training beyond high school? Do they also earn a credential?
  • What are the employment outcomes for adults with these credentials?

But key data to answer these questions were missing. The federal government had collected data on educational attainment and employment for many years, but did not regularly collect information on the number of adults with work-related credentials—

  • An industry-recognized certification shows that someone has demonstrated he or she has the knowledge and skills to perform a job.
  • An occupational license gives someone the legal authority to perform a job, and typically is also based on demonstrated knowledge and skills.
  • An educational certificate shows that someone has completed an occupational or technical course of study at a technical school, college, or university.

As the Department of Education’s research and statistics arm, IES recognized the importance of filling this data gap so that policy officials could have complete and accurate information for better decision making. Since 2009, the IES’ National Center for Education Statistics (NCES) has funded and staffed a rigorous survey item development process under the guidance of the Interagency Working Group on Expanded Measures of Enrollment and Attainment (GEMEnA)

Based on GEMEnA’s work, in January of 2014 the Census Bureau released the first official federal statistics on the number of adults with these kinds of work-related credentials. This year the Current Population Survey and the National Survey of College Graduates are collecting data on certifications and licenses that will greatly expand our ability to analyze their value in the workplace.  In 2016, NCES will field an Adult Training and Education Survey for the first time as part of the National Household Education Survey. 

Rigorous survey item development is time consuming and expensive. By investing in this work now, IES has helped to ensure that policy makers will have high quality data on education, training, and credentials to inform policy for years to come.