¶ … Myers-Briggs Type Indicator (MBTI), a tool used to measure psychological or personality types. The MBTI is described, discussing its purpose and design, format, and standardization sample. The psychometric properties of this test are then discussed. First, the reliability of the MBTI is demonstrated through test-retest and Alpha coefficient measures, then the MBTI's validity is demonstrated through predictive, construct, concurrent, and heuristic measures. A number of uses for the MBTI in a counselling setting are described; primarily, its ability to promote discussion, help individuals gain self-insight, and better understand the differences between themselves and others. This paper concludes with a discussion of the MBTI's strengths and weaknesses. For this assignment I choose the Myers-Briggs Type Indicator (MBTI) to review (Fleenor, 1998). The MBTI is based on Jung's (1923) theory of psychological traits and was created in 1942 by a mother daughter team, Katharine Briggs and Isabel Myers, in order to operationalize Jung's theory. The Mental Measurements Yearbook reports that no other personality inventory in history has been as widely used as the MBTI is today.

Description of the MBTI

Purpose and Design

The MBTI, which can be used on any male or female over the age of 18, assesses psychological or personality types on four dimensions: Extroversion/Introversion, Sensing/Intuition, Thinking/Feeling, and Judging/Perceiving (Cross & Swiatek). The MBTI classifies these four categories as followed: (1) Introverts are more internally oriented and extroverts are more externally oriented. Therefore, introverts will feel drained by social encounters whereas extroverts will gain energy from social encounters. (2) Sensing types tend to gain information primarily through the senses whereas Intuitive types think more abstractly and look for hidden meanings. (3) Thinking types are logical and organized thinkers, viewing many things in bipolar dimensions, whereas Feeling types are better at perceiving, analyzing, and understanding the feelings of others. (4) Finally, judging types are organized, they plan everything out, and they enjoy having control over most situations. Perceiving types are spontaneous, flexible, and open-minded individuals who adapt well in most situations. This test can be used to help individuals gain self-insight, or to help professionals better understand their clients.

Format

The MBTI is a self-report questionnaire written at a seventh-grade reading level and consists of 94 forced-choice items on four bipolar discontinuous scales (Chamorro-Premuzic et al., 2007). After completion of this test individuals are classified into one of 16 personality types based on their highest score in each of the four dimensions. For example, if an individual scores higher on Extroversion than Introversion, Intuition than Sensation, Thinking than Feeling, and Perceiving than Judging, then that individual would be classified as an Extroverted, Intuitive, Thinking, Perceiving type.

Standardization Sample

In order to analyze and weigh the items on the MBTI, a national sample representative of U.S. adults over the age of 18 was used (Fleenor, 1998). Nevertheless, this sample consists more of older individuals, females, and Caucasians; thus, caution should be taken when interpreting MBTI results (Hess, 2002).

Psychometric Properties

Reliability

Reliability refers to internal consistency, or the extent to which a test or measurement produces the same scientific observation each time it is applied (Hess, 2002). The MBTI has demonstrated various forms of reliability, such as test-retest reliability and Alpha coefficient reliability.

Test-retest reliability has been demonstrated using the MBTI (Fleenor, 1998). Three samples of people were given the MBTI test and were asked to retake this test four weeks later. Their preferences for the four dichotomies were then analyzed. The results showed that 55% to 80% (an average of 65%) of participants reported the exact same preferences on both tests. In addition, the authors of the MBTI manual report a number of studies reporting the MBTI's Alpha coefficients, which range from .57 to .85 with a median of .77 (Hess, 2002).

Validity

Validity refers to empirically supported interpretations of a test (Hess, 2002). The MBTI has demonstrated various forms of validity, such as predictive validity, construct validity, concurrent validity, and heuristic validity.

Predictive validity has been demonstrated between the MBTI and two measures of intelligence: the Graduate Management Assessment (GMA-A), which measures both fluid and crystallized intelligence, and the Watson-Glaser Critical Thinking Appraisal (WGCTA), which measures crystallized intelligence (Chamorro-Premuzic et al., 2007). The results of this study, which was conducted on 3500 males and females holding managerial positions, found that the MBTI's measures of personality type is a significant predictor of intelligence scores on the GMA -- A and WGCTA.

In addition, the authors of the MBTI manual report the construct validity of the MBTI's four factor model using conformity factor analysis (Fleenor, 1998). The four factor...

Furthermore, the MBTI manual reports a number of other studies which demonstrate the MBTI's concurrent validity by comparing its facet and preference scales to a number of other personality measures (such as the California Psychological Inventory, Fundamental Interpersonal Relations Orientation-Behaviour, Eysenck Personality Questionnaire, and the Rotter Locus of Control Scale) (Hess, 2002). The majority of these comparisons demonstrated correlations which were in the expected direction.
Finally, in a Mental Measurements Yearbook Review of the MBTI, it was said that this test has heuristic validity because for half a century it has been one of the most popular tools used is counselling and employment settings (Hess, 2002).

Use of MBTI in Clinical Settings

A number of studies have been conducted on the use of personality tests among counselling students (Freeman et al., 2007). The majority of these studies have found that personality types or traits of counselling students have a statistically significant impact of the type of psychotherapeutic approach they choose to employ. That being said, Freeman et al. did not find the same results. They conducted a study on 132 counselling students by having them complete the MBTI test along with the Self-Directed Search (SDS), which measures personality and career interests (e.g. investigative, artistic, conventional, etc.). In addition, the student's preferences for psychotherapeutic approaches were determined using the Counsellor Educators Survey (CES) which classified 18 of the major psychotherapeutic approaches into one of three broad categories (i.e. affective, behavioural, and cognitive). The results of this study were calculated using the Discriminant Function Analysis, a tool that is used to predict and explain "the relationships that impact the category in which an object is located" (Freeman et al., 2007, p. 259). This analysis found that neither the MBTI nor the SDS predicted choices of psychotherapeutic approaches. Although these results contradict those found in a number of other studies, the test was designed differently. As previously stated, Freeman et al. classified 18 of the major psychotherapeutic approaches into one of three broad categories, whereas the other studies used four. The researchers stated that some therapeutic approaches may not have been represented adequately by one of the three classifications. For example, solution-focused and solution-oriented were two therapeutic approaches which were less clearly classified.

In addition, it is stated in the Mental Measurements Yearbook that the results of this test can be a useful tool for instigating and encouraging open dialog between a counsellor and a client (Hess, 2002). As well, counsellors can use this test can help their clients gain valuable self-insight and understand individual differences in themselves and others (Fleenor, 1998).

Strengths and Weaknesses

Strengths

The Mental Measurements Yearbook states that the MBTI is a useful tool for helping people understand differences in personality type and increase self-insight (Fleenor, 1998). Furthermore, the test's long-held popularity among professionals is sited as one of its strengths, along with the MBTI manual itself, which is well written and contains extensive information, including in-depth knowledge on how to interpret the test results (Hess, 2002). Finally, the test has been praised as a tool which works as a stimulus for conversation in counselling and employment settings.

Weaknesses

The Mental Measurements Yearbook states that the MBTI cannot be fully recommended until additional analysis is conducted for categorical data (Fleenor, 1998). The authors of the MBTI manual stress that this test is not meant to measures personality traits on a continuous scale; but rather, it is designed to sort individuals into types. Nevertheless, the authors frequently report studies in their manual that utilize continuous scores as evidence of the instrument's validity and reliability. In addition, the Mental Measurements Yearbook states that further validational research, particularly in the area of predictive validity, should be conducted before the results of this test are used to make clinical, employment, or forensic decisions (Hess, 2002). Finally, in terms of the standardization sample used, although considered a representative sample of U.S. adults over the age of 18, the sample is weighted more towards older individuals, females, and Caucasians. Thus, caution is advised when interpreting these results for people who do not fall into any of these categories (Hess, 2002).