Various models look at personality differences for the purposes of career decisions, life planning, job assignment and team building. Most personality assessment is done through self-report with individual response to items varying according to mind set, vocabulary, life experience, culture and so on. The usefulness of the model is determined by the accuracy of both the model and the instrument used. If the instrument and the resulting descriptions do not accurately describe the individual, the model will be rejected. This may indicate weakness in the model, the instrument or in the administration and feedback process. Most self-report psychological instruments are designed to be used with professionally facilitated feedback.

Since the Myers-Briggs Type Indicator^® (MBTI^®) and the Keirsey Temperament Sorter are based on theories that address the innate nature of the personality, it is very important to help individuals get at what we call “true type.” This is the inborn pattern or potential, the source of our identity. Some would say it is the DNA. This is not to say the expression of our individual personalities is always in sync with this pattern. In fact many of us have been so influenced by our environment, we adapt or alter our inborn personality tendencies almost beyond recognition.

Why is it so important to get to “best-fit type”?
In our understandings and research about personality, we have come to recognize that to behave in ways not consistent with one’s inborn pattern takes a tremendous amount of energy. In fact, it is highly related to stress. Temperament and type dynamics theory states we have favorite abilities that help us meet our psychological needs. These are specific to each temperament. When we get to use these “intelligences,” we not only tend to excel, we also feel good about ourselves and are energized. In fact, it seems we find ways to use these talents even when they are not part of the job.

That is not to say we never should take on roles inconsistent with our innate pattern. In fact, the push for growth that comes with type development often leads to career transitions into such roles. If we are conscious of our preferential pattern and the development it would naturally take, we can embrace the stress of such a change and allow for the extra energy drain.

How then, can we accurately help individuals find their “best-fit type?” The answer lies not in any one instrument such as the Myers-Briggs Type Indicator^® or the Keirsey Temperament Sorter, but in the appropriate use of these instruments.

Choice of Instrument
The instrument chosen must meet the following criteria:

• Be reflective of a trustworthy theory or even theories.
  • Both the MBTI^® and the Keirsey Sorter reflect trustworthy theories.
  • Jung’s theory of psychological types has stood the test of time and a multitude of users.
  • Keirsey’s temperament theory reflects patterns of behavior that have been described by many great thinkers for over 25 centuries.
  • Both instruments work fairly well with both theories.
  • Temperament and Type Dynamics reflects the integration of both theories.
• Be reliable; that is, work in the same way each time.
  • Correlations of more than + or – .70 between two administrations on test-retest are considered adequate. The MBTI^® exceeds that requirement.
  • While there is no published data on the Keirsey Sorter, there were initial reliability correlations at an acceptable level.
• Be valid; that is, accurately represent the theory.
  • The acceptable range of correlations for establishing validity is from + or – .20 to .60. Usually the new instrument is compared to existing instruments.
  • The MBTI^® fared well in such correlations, although most of the correlations were with continuous scores on individual scales, not remaining true to Jung’s theory of types (whole types, not preference scales).
  • The Keirsey Sorter correlated at an acceptable level with the MBTI^®. No published data is available.
• Be accurate
  • Both instruments seem to have a “error” rate of at least 25%. When a feedback session is conducted and the client confirms their type, the instrument results do not match the confirmed and/or observed type about 25% of the time. Some practitioners would say it is higher.

Appropriate Context
Inappropriate contexts contribute to this inaccuracy rate. For example, when someone wants a job, they are not likely to be in a frame of mind to accurately self-report. It is not that people intentionally lie, they just do what it takes to survive, sometimes fooling themselves as well.

Self-report instruments are more accurate when the client is in need of the information, feels safe and is “motivated” to accurately self report. Any time a self-report instrument is used in a context where there is even a slight fear of losing one’s job or one’s self esteem, the error rate will go up. A good feedback session can mitigate this effect.

Verification of Results
Since many people are fascinated by and trusting of paper and pencil instruments, they tend to trust the results of those instruments rather than relying on the interactive, face-to-face feedback and their own self-confirmations. In our primarily western culture, there has been an overemphasis on rational, external measurement and a distrust of introspection and self-verification. Given the expense in time and money, many are tempted to use these instruments without feedback and confirmation/verification. This can be especially disastrous and costly when done in an attempt to use the theory for placement in positions and or hiring.

For many people, taking a paper and pencil “test” is magical. It provides the catalyst for self reflection not present before. It is only one way to interact with the framework. However, the key to having the “test” work its magic is good, elegant descriptions that ring true for each type. These descriptions are often provided in a workshop format, an individual feedback session or in written form. We recommend providing group experiences with feedback from others as well as providing a variety of descriptions for participants/clients to read.

A related issue is what is the value of the MBTI^® or other professionally administered instrument when someone can access a personality questionnaire in a self-help book or over the Internet? We must go back to the importance of getting at “true type.” If they can have an ah-hah experience when they do that, then so be it. If not, then more is needed. Given the fact that no self-report instrument is perfect and most of us have adapted to our environment in one way or another, then more is needed indeed.

When someone administers the MBTI^®, it is not the results of the individual’s interaction with the instruments that provides the power and impact. It is the trustworthiness of the theory and how elegantly that theory is reflected in the instrument as well as how elegantly that theory describes the essence of one’s personality.

Related to that trustworthiness are two other factors. One question to ask is, “How well-grounded is the facilitator in the theories and how well-trained in accurate “interpretation” of the results and in giving feedback?” This is the essential ingredient that allows each individual to arrive at an awareness of their “true type” (the ah-hah experience so many of us have had). Another is, “How well-written and well-founded are the written materials provided as background?”.

Different Scores on Different Assessment
Many people take the MBTI^® or the Keirsey Sorter at different times. Frequently, they come out differently with each taking. Given what we know about self-report instruments, it is to be anticipated that people will come out differently at different times. First off, there has usually been other kinds of interactions with the frameworks between the administrations. Once one has heard or read an explanation of the temperaments and the preferences, it changes how one views the items. Depending on the mind set and the person’s nature, the second taking may be more accurate than the first, or it may be skewed by some misconception from the information given, or it may be affected by one’s desire to be different and so on.

There are also differences in different tools even though they are developed out of a common theoretical base. The MBTI^® was developed based solely on the work of Carl Jung. David Keirsey’s use of the MBTI^® to access the temperament patterns changed the kind of information available to people about type. When he published the Sorter, it was as a self-help tool, designed to get people to relate to the information in the book, Please Understand Me. People began using the Keirsey Sorter to get at type because it was shorter. Some even call it the short form of the MBTI^®. This is an error. Even though it uses the same language as the MBTI^®, none of the items are the same. Dr. Keirsey even constructed it to avoid some problems with the S-N scale that he observed with the MBTI^®. So it is not surprising that some people will score differently on the two instruments, while some will score the same.

Neither the Keirsey Sorter nor the MBTI^® get at the temperament pattern directly; that is, by looking at the themes and patterns of the four temperaments. 

The Bottom Line
There is a close relationship between the theories and the instruments used to access those theories. They cannot be separated. The usefulness is in the theory and its applications. The impact is in the feedback, not just the instrument. If you do not know enough of the theory to use the theory without an instrument, you should not be using any instrument. On the other hand, an instrument makes the theory more easily accessible. It is important to keep focused on the goals of increased self-awareness, empowerment and self-esteem in using personality information to make career decisions, find the right fit with a job and making teams more productive. Instrumentation is only one part of the toolkit. Feedback by a competent professional is the other.

Temperament Research Institute trains professionals in the competencies required to provide accurate administration and feedback of the MBTI^® as well as the applications of the open systems model of Temperament and Type Dynamics. We also provide individual Personal Mastery sessions and Team Mastery sessions using these powerful frameworks.