QUOTE: The Myers–Briggs Type Indicator (MBTI) is an introspective self-report questionnaire with the purpose of indicating differing psychological preferences in how people perceive the world around them and make decisions. The original versions of the MBTI were constructed by two Americans, Katharine Cook Briggs and her daughter Isabel Briggs Myers. The MBTI is based on the conceptual theory proposed by Swiss psychiatrist Carl Jung … The four categories are Introversion/Extraversion, Sensing/Intuition, Thinking/Feeling, Judging/Perception. 
NOTE: Each person is said to have one preferred quality from each pair, producing 16 unique types made up of four letters. The significance of the four-letter type in the simplest understanding of the theory is that it helps to rapidly clarify a person’s preferences; it is more a tool for self-understanding than to diagnose or solve emotional or job function problems. Others have developed the theory far beyond this simple understanding.
The online links below provide an opportunity to take an online test which will provide an understanding of your 4 Letter combination based on the Myers-Briggs understanding hope personality type. it is also possible to take the actual Myers-Briggs Type Indicator (MBTI) for a small fee. Once you have a four-letter combination you can Google it for numerous interpretations of those preferences. Again, these tests help to clarify personal preferences. It may be necessary to test out different letters to see if one set better explains a person’s understanding of their preferences.
My favorite resource for this topic are the books written by Otto Kroeger known as TypeTalk. https://smile.amazon.com/Otto-Kroeger/e/B000AP71NO?ref=sr_ntt_srch_lnk_2&qid=1569590627&sr=8-2
My second favorite resource for this topic are the books written by by Paul D. Tieger and Barbara Barron-Tieger. Their website (and test) is located here: https://www.personalitytype.com/
Human Metrics http://www.humanmetrics.com/cgi-win/jtypes2.asp
The Myers and Briggs Foundation https://www.myersbriggs.org/my-mbti-personality-type/mbti-basics/home.htm?bhcp=1
QUOTE: The Keirsey Temperament Sorter (KTS) is a self-assessed personality questionnaire designed to help people better understand themselves and others. It was first introduced in the book Please Understand Me … The KTS is closely associated with the Myers–Briggs Type Indicator (MBTI); however, there are significant practical and theoretical differences between the two personality questionnaires and their associated different descriptions. 
NOTE: The KTS reduces the 16 unique types made up of four letters of the Myers-Briggs to four “temperaments” which are easier to apply and understand and which are made up of two of the four letters: SJ, SP, NT and NF. The significance of the two-letter type in the simplest understanding of the theory is that it helps to consider people’s behavior in groups. Others have developed the theory far beyond this simple understanding.
The Keirsey professional practice, more information on the theory and an opportunity to discover your “temperament” is available here: https://www.keirsey.com/
What is your Myers-Briggs type? Does it seem to fit?
Type Talk: The 16 Personality Types That Determine How We Live, Love, and Work by Otto Kroeger and Janet M. Thuesen. https://smile.amazon.com/gp/product/B00ATLA9VU/ref=dbs_a_def_rwt_hsch_vapi_tkin_p1_i0
Do What You Are: Discover the Perfect Career for You Through the Secrets of Personality Type by Paul D. Tieger, Barbara Barron and Kelly Tieger. https://smile.amazon.com/Do-What-You-Are-Personality-ebook/dp/B00ECE9N2G/ref=sr_1_1?keywords=tieger&qid=1569591136&s=digital-text&sr=1-1
SOURCE – Footnotes:
 “Myers–Briggs Type Indicator” From Wikipedia, the free encyclopedia, https://en.wikipedia.org/wiki/Myers%E2%80%93Briggs_Type_Indicator
 “Keirsey Temperament Sorter” From Wikipedia, the free encyclopedia, https://en.wikipedia.org/wiki/Keirsey_Temperament_Sorter
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