What is Psychometrics?
Learn about the field of psychometrics
Even if you are not familiar with this branch of psychology, psychometrics has probably been affecting your life for years and you may not even realize it. Remember taking that placement exam in high school? Or perhaps you recently took a personality test as part of a job interview or group-building exercise at work? Have you ever taken an IQ test?
All of these tests are an attempt to reveal aspects of a person’s aptitude or personality. Psychometrics is the science of how professionals try to uncover those aspects in a statistically valid, quantifiable manner. Psychologists want to not only understand the way the mind works, but also to quantify its functioning, and to compare those findings among groups of individuals.
Today, psychometric testing is used in every aspect of modern life—from elementary schools, to corporations, the military, and prisons—in an attempt to assess personality, ability, and, therefore, behavior. The tests are broken down into the following categories:
- Educational testing. Educational testing focuses on learning development, competence, and aptitude.
- Health testing. Health testing is applicable to those with learning disabilities, alcohol and drug related issues, behavioral difficulties, sensory impairments, and assessing brain function after an injury or trauma.
- Occupational testing. Occupational testing is utilized in schools, social service agencies, and businesses. Psychometrics is used in team building, vocational counseling, aptitude testing, career development, and understanding organizational culture in a workplace.
Who develops and administers tests?
Psychometric tests are developed by psychometricians: career psychologists who also specialize in statistics. Psychometricians are concerned with the design and development of the tests, the procedures of testing, instruments for measuring data, and the methodology for understanding the results.
Tests range from standardized multiple-choice tests (true/false questions are less favored) to free-association picture tests, scenario-based questions designed to elicit responses about beliefs and values, and a variety of formats including reading comprehension and mathematical problems. Tests all contain questions designed to minimize testing biases, false positives, and test-taker deception. To accomplish this, the psychometrician will design into the test a number of questions asking the same thing in different ways.
Tests are administered by a psychologist in clinical settings at universities, in classrooms boardrooms, hospitals or during private psychotherapy sessions. Other professionals administer psychometric tests as well, outside of clinical settings.
Psychometricians employed by a school or school district are responsible for administering tests in classroom settings facilitated with help from teachers. Licensed counselors working in schools, social services, the military, and private practice also administer psychometric tests. Trained human resource managers often are responsible for psychometric testing in the workplace.
The widespread availability of these tests, while providing opportunity for expanding knowledge in the field, has also fueled criticism of the tests reliability.
As the science of psychometrics evolved, the need for greater reliability and validity of measurement became necessary – concepts that determine the quality of a test and its results. Reliability is the extent to which a test yields consistent results--among users, administrators, and over time. Validity is the extent to which test results are applicable to the real world. (See article on Psychological Assessements)
Because many of the factors being measured in psychometric testing are unobservable to a researcher, such as an individual’s preference for leading versus following, or a preference for black versus red, social scientists have taken great care to make consistent their testing methods and data analysis.
In addition, they have worked to eliminate many forms of testing bias, a statistical error resulting from both administrators’ and test-takers’ moods, perceptions, unconscious decision making, and variability between cultures and time periods.
While some tests have been in use for dozens of years and are trusted sources of information, such as the Stanford Binet Intelligence Scale, others are less common and used only in clinical settings. Today, others are readily available on the Internet, but these online results are often statistically or psychologically questionable. Many tests offered on the web are based on established psychometric tests but are more for entertainment and don’t stand up to statistical rigor.
For a test to be used in clinical studies, mental health counseling, or by human resource managers, it must be validated by a governing body such as the American Psychological Association (APA) or the British Psychological Society. Examples of such accepted psychometric tests include the Graduate Record Exam, the Strong Interest Inventory, and the Myers-Briggs Type Indicator personality inventory.
In order to regulate testing and promote responsible use of validated tests, governing bodies created a manual of standards and guidelines for psychometric tests. The Standards for Educational and Psychological Testing were created by a joint effort of the APA, the National Council on Measurement in Education, and the American Educational Research Association.
Standards are reviewed and updated every several years and incorporate changes in law and updates in validity testing and social understanding, such as testing individuals with different cultural backgrounds and disabilities, to continue to minimize bias error in testing. These standards are designed for use by psychometricians as well as professionals working in education, counseling, and employment. They address issues such as fairness and the rights and responsibilities of test takers and administrators.
The implications of non-standardized or non-validated tests are obvious. Opponents fear that great mental, social and legal harm can be done when unsubstantiated results from poorly constructed or unvetted tests are used in childhood development, the workplace, or a court of law.
Opportunities rising for those in psychometrics
An increased use of psychological assessment and testing in the workplace has caused the field of Psychometrics to expand rapidly over the last several years. Dozens of companies worldwide offer psychometric testing services, competing for the business of schools, governments, and private corporations. This includes providing the tests, the instructions for administration of the tests, and providing the analysis and results to clients.
One field that especially draws on the expertise of psychometricians is Industrial-Organizational Psychology (see What is Industrial-Organizational Psychology?) These psychologists apply psychometrics in employee selection and training; performance analysis; and workplace organization.
Psychometricians also work in universities, school systems, and in private practice. Working in research, psychometricians typically possess a master’s degree or higher. When working in the educational system, psychometricians are almost always required to obtain a Certification in Psychometry. (See Careers in Psychometry).
Psychometrics in Practice
Psychometrics has now come to encompass all aspects of psychological testing, ranging from early intelligence tests to post traumatic stress disorder (PTSD) tests to personality and interest tests.
There are three main areas that psychometric tests measure.
1. Personality. The assessment of personality includes quantifying personal qualities, beliefs, values, style, and behaviors of individuals in their environments and in relation to other people. Tests to measure personal qualities ask questions about preference, beliefs about oneself, how strongly one holds to these feelings, and perceptions of self and others.
2. Aptitude. The measurement of aptitude includes an individual’s ability to hit certain levels or markers in a particular skill, such as reading or mathematics. Aptitude tests are utilized throughout a person’s educational lifetime, from elementary school reading tests to the ACT and GRE. They are also used to determine intellectual giftedness or learning disabilities.
3. Interest. While sometimes combined with personality tests, the measurement of a person’s interests includes preferences, motivations, and the strength of his or her values and opinions. Career counselors and high school counselors most often use interest tests. The California Psychological Inventory (CPI) test and the Strong Interest Inventory are examples of these types of tests.