Psychometrics is a field of study concerned with the theory and technique of psychological measurement. One part of the field is concerned with the objective measurement of skills and knowledge, abilities, attitudes,personality traits, and educational achievement. For example, some psychometric researchers have, thus far, concerned themselves with the construction and validation of assessment instruments such as questionnaires,tests, raters' judgments, and personality tests. Another part of the field is concerned with statistical research bearing on measurement theory (e.g., item response theory; intraclass correlation).
As a result of these focuses, psychometric research involves two major tasks: (i) the construction of instruments; and (ii) the development of procedures for measurement. Practitioners are described as psychometricians. Psychometricians usually possess a specific qualification, and most are psychologists with advanced graduate training. In addition to traditional academic institutions, many psychometricians work for the government or inhuman resources departments. Others specialize as learning and development professionals.
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. For more information, see psychological assessments.
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. 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.
To learn more about the world of psychometrics and career options in this field, request information from schools offering degree programs in psychometry or related psychology programs.
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.
- 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.
- 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.
- 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.
What is psychometrics?
We’re all aware that individuals are unique and not everyone likes the same things. This uniqueness comes directly into play in the field of marketing. Since no two people are identical, marketing is about grouping and targeting. That is, higher levels of marketing success arise if you know who to target and how to target them instead of targeting everyone with a generic message. This necessity for specificity means targeting is essentially an empirical question that requires some form of measurement. Consumer behavior is ultimately a result of psychological processes and thus is an optimal target for measurement. Many people don’t think of individual or group characteristics as quantifiable entities, but they can be. Indeed, once you develop a method of quantification, objective grouping based on numbers becomes much easier and more reliable than subjective grouping based on descriptions of consumer traits. Clearly not all measurement is good measurement, so then the question becomes: “How should this measurement be done?” This is where psychometrics comes in.
People often think of psychology as observational and descriptive, but there is a mathematical side to psychology as well. Psychometrics is the field of study that attempts to measure and quantify the classic ‘descriptions’ that psychology insights offer us. One example of a psychometric measure is that of IQ, or the intelligence quotient. It’s one thing to say someone is very smart or not that smart, but having a psychometric formula for this characteristic allows us to assign its value an actual number for any given individual.
The goal of psychometrics, and the reason it is so valuable, is it allows us to measure things that usually are not thought of as measurable. Once something is quantifiable it becomes increasingly easier to investigate, analyze and use in further models.
Generally speaking, the psychometric measurement formula goes something like this:
- Determine what you want to measure
- Create test for what you want to measure
- Run test
- Determine reliability and validity of test
- Refine methods of measurement: Lather, rinse, repeat
This process is accomplished using various testing methodologies such as surveys and questionnaires to create the test and then using statistics to analyze the results and refine the process. Three important paradigms for this process are the Classical Test Theory, Item Response Theory and the Rasch model.
The Intersection of Marketing and Psychometrics
Aside from its theoretical value, psychometrics offers a channel for valuable insights when it comes to marketing. Three such applications are described below.
As mentioned above, using psychometric methods to assist in customer segmentation decreases subjectivity and increases reliability of customer segmentation. Being able to describe your customers numerically allows for the generation and refinement of descriptive models that facilitate segmentation and psychometrics are the best way to create this numeric definition of consumer behavior. Most, if not all, traditional methods of segmentation -- for example, demographics -- are at best proxies for psychological variables. Being able to break these segmentations down into the pertinent psychological processes and then quantify them allows for a fuller and more accurate view of consumer behavior.
2. Additive and interactive effects
As your description of an ideal customer becomes more complex, it becomes more difficult to accurately find these customers using subjective techniques. Imagine you have a Product A and know ‘nice’ people really like it, so you then tell five people to go out and find one nice person to sell your product to. Chances are, all of these people have a different definition of what ‘nice’ is and their definitions are different from your definition. Because of these subjective discrepancies, the potential customers your five people chose might not represent the best circle of consumers for your product. Now imagine Product A needs to be sold to consumers who are not only nice, but also smart. An extra dimension of subjectivity is added into your search, making it that much harder for your employees to find the right customers. This difficulty can be assuaged using psychometrics. Using numbers (via psychometric measures) not only makes it easier to know who you’re looking for, but also makes it easier to find those people and to confirm you have the right people.
3. New Insights
Since there is a whole field of study -- mathematics -- dedicated to how numbers behave with other numbers and another -- statistics -- dedicated to how to analyze these interactions, using numerical measures of psychological constructs allows for a lot more flexibility and creativity when it comes to generating insights about consumer behavior that is grounded in psychology. Additionally, segmentation along relevant psychological dimensions, as opposed to just proxies for these dimensions, allows for the development of a strategy in terms of what to do once the customer segmentations are formed and more reliable and valid data. For example, the psychological aspects of segmentation of this sort can give insight into how to approach your newly found people, how to formulate messages directed toward them, how to design packaging, how to develop product features, etc. Through psychometrics, psychological dimensions become a powerful resource for all aspects of marketing and brand management.