All this coming week, 10News Today is exploring the world of personality tests -- and we're starting off Monday morning with one that is arguably the most well-known through the years: The Myers-Briggs Type Indicator.

Taking the Test

The official MBTI test provided by CPP – The Myers-Briggs Company is the only true Myers-Briggs personality test and costs a fee to take.

However, there are a few free tests available to take online using a similar personality assessment style, such as one from 16Personalities.

The tests will ask for you to honestly rate how you feel about yourself in a variety of ways, such as if you enjoy taking initiative in social situations, if you see yourself as an organized person, etc.

What is the MBTI Measuring?

To put it simply: The MBTI is measuring where you fall among 16 different general personality types.

It bases these 16 types by testing a person's about how they perceive themselves to be or act in certain situations, and compares those responses to choose between two personality aspects divided in four different categories: Introversion/Extroversion, Sensing/Intuition, Thinking/Feeling, and Judging/Perceiving.

The 16Personalities test adds in an extra category not found in the MBTI, Assertive(-A)/Turbulent(-T), which gauges if a person is self-assured/relaxed (Assertive), or self-conscious and driven to improve (Turbulent).

Introversion and Extroversion are determined from how people interact and if they are inwardly or outwardly focused. (I)ntroverted types tend to prefer solitude and with a low-key attitude, while (E)xtroverted types seek social interaction and are frequently enthusiastic.

Sensing and Intuition are determined by how a person focuses their attention and processes information. A (S)ensing type is pragmatic and focuses on what's in front of them and the "what is," and an i(N)tuitive type is interpretive and tends to look below the surface and engage with the 'what if'.

Thinking and Feeling are determined by how you make decisions and resolve conflicts. A (T)hinking type bases their decisions on logic and rationality, and a (F)eeling type focuses on social harmony and cooperation.

Judging and Perceiving are based on structure and tactics. A (J)udging type is highly structured and organized, preferring clarity and predictability. A (P)erceiving type is one that enjoys improvisation, preferring flexibility and keeping options open.

Once the test decides which aspect best represents you within the four categories, it assigns a letter for each to place you in one of the 16 personality types (which are highlighted in parentheses above). For example, a person that had extroverted, sensing, thinking, perceiving aspects would be an "ESTP."

What are the 16 Personality Types?

The official MBTI test stops short of providing an extra identifying category or overarching temperament for the 16 personality types beyond the four letters, however, the 16Personalities version of the test includes one based on the "Keirsey Temperament Sorter."

You can find a brief description of each of the types from the Myers & Briggs Foundation here.

Flaws with the MBTI

In recent decades, the MBTI and other similarly styled tests have been criticized by personality psychologists who say it uses a flawed, outdated methodology. Some even say it's just a fad that refuses to die, likening it to horoscopes or astrology with little scientific merit.

Specifically, critics point to the lack of reliability and consistency in the test results -- saying large numbers of people have been found to receive different results upon retesting within a short period to time.

Searching for famous examples for each type also showed inconsistent results, as there were multiple interpretations for many celebrity and political figures. Some were all over the board, so the most common interpretation was chosen as examples here.

However, other psychologists argue the even though the 16 personality types might not result in perfectly consistent fits -- it still presents a useful tool for self-insight and understanding.

So, take it with a grain of salt! It's certainly interesting and insightful, but your results need not become a self-fulfilling prophecy.

The MBTI isn't the only popular personality test. Wake up early this week to watch 10News Today starting at 5:00 a.m. until 7:00 a.m. ET-- each day we'll be covering other emerging personality tests gaining a lot of support such as "The Big Five" and Enneagram models.

Editors Note: Myers-Briggs Type Indicator, Myers-Briggs, and MBTI are trademarks or registered trademarks of The Myers & Briggs Foundation in the United States and other countries.