Hi,

I want to model a database corresponding of the "Myers-Briggs Type Indicator" idea of classification.

Basically he uses dichotomies as follows:
Extraversion (E) - (I) Introversion
Sensing (S) - (N) Intuition
Thinking (T) - (F) Feeling
Judging (J) - (P) Perception

and from the dichotomies a matrix table is produce as follow:
ISTJ ISFJ INFJ INTJ
ISTP ISFP INFP INTP
ESTP ESFP ENFP ENTP
ESTJ ESFJ ENFJ ENTJ

The rules are that:
- E or I cannot be put together it is either E or I, the same goes for S&N, T&F, J&P.
- The order is important.
- The all four concepts should be added together and not one should be missing otherwise it does not make any sense.

There is also the concept of traits which for my perspective should be another table. Ex: Shy is a trait and shy refers to (I) Introversion.

These are the concepts I am a little confuse how to model.

I thought about doing something like

Table characteristic (Id, Name) ex of data:
E, Extraversion
I, Introversion
S, Sensing
etc...

Table Personnality type (Id, Characteristic_Id#1, Characteristic_Id#2, Characteristic_Id#3, Characteristic_Id#4)
ex of data
1, I, S, T, J
etc...

but I feel like the repetition of the filed 4 times is not very proper isn't it?

Could you help me clarify a bit this concept oriented to the database? Note that I will have to do a lot of SQL to attack the db.

Thank you in advance for your time.
Clem.