If you are reading this paper you are probably familiar with the four-letter names that the MBTI uses to identify the 16 personality types into which it separates individuals - the INFP, INFJ, ENFP, ENFJ, ISFP, ISFJ, ESFP, ESFJ, INTP, INTJ, ENTP, ENTJ, ISTP, ISTJ, ESTP, and ENTJ. You will probably know that much useful information can be read directly from the type name itself - it tells you whether the individual is an 'introvert' or 'extravert', which function is the individual's dominant one, and so forth.

You are not likely, however, to be as familiar with the alternative nomenclature that we sometimes use at our site. What do we mean when we speak of the inFp, for instance, or the esTj? In this short piece we're going to try to describe, as briefly as possible, what we had in mind in developing this alternative labeling convention. Afterwards, John will be happy to entertain any questions that you may have about this matter and discuss with you in detail any of the issues that we've raised in this paper.

Section One - The First 3 Letters

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In the absence of an explicit explanation about the conventions that underly our alternative nomenclature, it can easily be misinterpreted in various ways. At first glance, for example, some who see the term 'iNfp' may think that we are talking about an introvert with a typical INFP preference order (F-N-S-T) who has an exceptionally strong iNtuitive function. But that is not at all what we mean by this abbreviation.

In the following we will try to articulate, as precisely as possible, the rules according to which our naming convention operates. In the course of doing this we will compare it to the traditional MBTI nomenclature. This should demonstrate the ONE specific difference between the convention we are suggesting and the one traditionally used in the MBTI. And, more importantly, it will begin to give you some idea WHY we believe this difference to be an important one.

We'd like to start with a simple fact that you may not be aware of - the fact that you only need to know two things about an individual in order to definitively and unambiguously establish that individual's MBTI type. All you need to know is the individual's functional 'preference order' and his or her orientation (I/E). If an individual is an 'I' (introvert), for example, and has an F-N-S-T preference order, there can be no doubt whatsoever, according to the MBTI, that he or she is an INFP. One cannot have that orientation and preference order without being an INFP. And, conversely, all INFPs will have that particular orientation and preference order.

The MBTI naming convention tells you that 'F' is the dominant function for this type, because P' in combination with the 'I' points to the third letter as the one representing the dominant function. If the first letter in the name were 'E', the 'P' would point to the second letter as the one representing the dominant function. Once one know that 'F' is the dominant function in the INFP, and 'N' the auxiliary, there is only one preference order that fits: F-N-S-T.

So far, so good. There is nothing in any of this yet with which anyone could disagree. These are simply facts about how the MBTI naming convention works.

But now lets take into consideration the fact that the four-letter naming convention that the MBTI uses is really just that - a convention. One can easily imagine establishing alternative type labels that express EXACTLY the same thing. Once more taking the INFP as an example, we could decide to indicate that he or she has an 'I' orientation and an F-N-S-T preference order by using a type-name that has only three letters - and assign the label 'inF' to such individuals. Instead of utilizing a fourth letter (a 'j' or 'p', like the MBTI does) to point to which of the two specified functions (feeling or intuition) is dominant, we could simply capitalize the dominant function.

The capital 'F' in 'inF' would indicate that feeling is dominant, and intuition is auxiliary. The 'i' in 'inF' tells us, of course, that the individual is an introvert. So the label 'inF' tells us everything we need to know in order to identify the individual's MBTI type. It is therefore an entirely acceptable subsitute nomenclature for the label 'INFP'.

And that, in brief, is what the first three letters of our nomenclature mean. Nothing more, nothing less. It is simply an alternate shorthand for identifying the individual's MBTI type - identifying that he is, in the case of the inF example, an Introvert with F-N-S-T preference order.

Similarly, the label 'iNf' would simply be shorthand for an introvert with N-F-T-S preference order - which, using the conventional MBTI nomenclature, could alternatively be labeled 'INFJ'. And so forth and so on with the remaining types, as follows:

	orientation & preference order	MBTI name
iNf =	I and N-F-T-S = Ni-Fe-Ti-Se	= INFJ
inF =	I and F-N-S-T = Fi-Ne-Si-Te	= INFP
eNf =	E and N-F-T-S = Ne-Fi-Te-Si	= ENFP
enF =	E and F-N-S-T = Fe-Ni-Se-Ti	= ENFJ
iSf =	I and S-F-T-N = Si-Fe-Ti-Ne	= ISFJ
isF =	I and F-S-N-T = Fi-Se-Ni-Te	= ISFP
eSf =	E and S-F-T-N = Se-Fi-Te-Ni	= ESFP
esF =	E and F-S-N-T = Fe-Si-Ne-Ti	= ESFJ
iSt =	I and S-T-F-N = Si-Te-Fi-Ne	= ISTJ
isT =	I and T-S-N-F = Ti-Se-Ni-Fe	= ISTP
eSt =	E and S-T-F-N = Se-Ti-Fe-Ni	= ESTP
esT =	E and T-S-N-F = Te-Si-Ne-Fi	= ESTJ
iNt =	I and N-T-F-S = Ni-Te-Fi-Se	= INTJ
inT =	I and T-N-S-F = Ti-Ne-Si-Fe	= INTP
eNt =	E and N-T-F-S = Ne-Ti-Fe-Si	= ENTP
enT =	E and T-N-S-F = Te-Ni-Se-Fi	= ENTJ

So, without using the 'J' or 'P' designation at all, we are able to generate a set of labels that stand for the same sixteen permutations of Orientation-plus-Preference-Order that make up the MBTI roster of 16 types. When you stop to think about it, the three-letter shorthand that we suggest is actually easier to 'read' than the MBTI type name. The dominant function is directly indicated by the capital letter. When you see eSt, you immediately know that S is dominant. You don't have to remember any complex rules - about 'I' in combination with 'P' (or 'E' in combination with 'J') pointing to the third letter as dominant, as opposed to 'I' in combination with 'J' (or 'E' in combination with 'P') pointing to the second letter as dominant.

Be that as it may, however, if we left the matter at this stage of development all we'd really have is a trivial example of a three letter nomenclature that could be used instead of the traditional MBTI nomenclature. It might be a bit easier to read, but it is still just an alternative nomenclature. It does not disagree with the MBTI. It doesn't call any assertion that the MBTI makes into question, or in any other way disagree with MBTI theory or practice.

Section Two - The Fourth Letter

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But lets now go one step further. To the first three letters of our new nomenclature we can easily imagine adding a fourth letter. Why would one want to do that if the first three letters are sufficient to specify preference order and orientation (and hence unambiguously define 'type')? Well, we might want to use a fourth letter to give a further bit of information about the individual.

Perhaps the fourth letter could be used to tell us whether or not the individual likes dogs (D) or cats (C), or is left handed (L) or right handed (R). Or perhaps it could be used to indicate whether the person has a tendency toward closure or not. To indicate a tendency toward closure, we could use the letter 'j' as the fourth letter, and to indicate a tendency toward non-closure, lets use 'p' as the fourth letter. And lets further specify that the 'J' and 'P' scales on the MBTI are to be used to test for 'j' and 'p'.

If a particular inF, then, turns out to have a tendency toward non-closure, by testing as a 'P' on the MBTI, we would signify this accordingly - by saying he is an 'inFp'.

'But how does this differ from the MBTI?', you might ask, perhaps a little bit frustrated at this point with all the detail that seems to be getting us nowhere. 'Aren't you still just saying the same thing as the MBTI?'

No. Not exactly. Granted, in the case of the inFp there is no difference - call the person an inFp or an INFP and it doesn't really matter - both amount to the same thing: an introvert (I) with F-N-S-T preference order and a proclivity toward 'p' (non-closure). But now consider this: to the first three letters in our new nomenclature, 'inF', you could also theoretically add a 'j' as the fourth letter - a possibility that isn't allowed in the MBTI!

This possibility isn't allowed in the MBTI because, according to the ASSUMPTIONS underlying the MBTI, since the orientation is 'I' and the preference order is F-N-S-T, one MUST add a 'p' to the first three letters, inF. If we want to act according to this assumption - that all Introverts with F-N-S-T preference order have 'p' traits (preference for non-closure, etc) - we'd have to say that every inF is an inFp.

But is this assumption TRUE? That is the $64,000 question!!!

If it indeed IS true, than the 'inF' must necessarily be equivalent to the inFp; and the 'p' in our new nomenclature would simply be redundant. Insofar as it is redundant, it would be best to simply drop it from the name and revert to the three letter characterization that we speak of in Section One above - inF.

But if it is not true that everyone who has an I orientation and a 'F-N-S-T' preference order is 'p', then some of those who are inF would in actuality turn out to also be 'j' !!! This would result in a new label, the inFj - standing for the person who is an introvert, with F-N-S-T preference order, but a 'j' disposition (prefering closure, etc). It would also result in 15 other previously unrecognized new type-labels. The new four-letter nomenclature would thus not be redundant at all, nor trivial. For it would open up 16 new possibilities that are by DEFINITION outlawed by the assumptions according to which the MBTI works.

We have taken pains in the above to clearly show that the only difference between our nomenclature and the original MBTI nomenclature is that in ours, the 'j/p' designation - the fourth letter - can be taken as a separate VARIABLE. J and P, in our notation, is conceived as varying INDEPENDENTLY with respect to both orientation (I/E) and preference-order, just like preference-order in the traditional MBTI varies independently of orientation (I/E). What our nomenclature does, in effect, is to separate out the TWO roles that the J/P designation plays in the MBTI, replacing one (the use of J/P to point to preference order) with a capital letter in the name, and reserving the other (the fourth letter) for the designation of the individuals tendency, or lack thereof, toward closure.

In addition to permitting the individual to score as (1) either an I or E; and 2) independently associating one of 16 preference orders to the individual; our new four-letter notation also (3) independently associates a preference for 'J' or 'P' to the individual. All three parameters (orientation, preference order, and J/P designation) are conceived as absolutely INDEPENDENT of each other.

But why, then, does the MBTI assume that J/P is not an independent variable?

This is the question that it is only natural to ask at this point, after seeing how our new four-letter nomenclature operates and comparing it to the old nomenclature. And this was exactly the point we were trying to make by proposing the new nomenclature in the first place. It was originally intended as a heuristic tool, a 'teaching device'. For it very clearly brings into relief one particular assumption that is made by the MBTI, a critical one, which we want to call into question - the MBTI assumption that J/P does NOT vary independently with respect to preference order and orientation (I/E).

What EVIDENCE is there for the MBTI assumption that J/P is NOT an independent variable? As far as we can make out, NO evidence is characteristically presented in behalf of this assumption. It is taken to be true 'by definition'. In other words, no evidence is even SOUGHT because the presumed 'dependent' relationship between certain combinations of preference-order/orientation and J/P preference is conceived as being BUILT INTO the definitions themselves.

But is this a legitimate argument in defense of such an assumption? No. In fact, this kind of argument is a fallacy that is in logic sometimes called 'begging the question'. If somebody, for instance, wanted to argue that the earth is flat, you would most likely challenge him. You'd want to know WHY he believes it to be the case that the earth is flat. If, in response to your question, he were simply to answer that he doesn't need any evidence because the word 'earth', the way he is defining it, includes in it the feature of flatness - you could correctly reply that he is 'begging the question'. And by saying that you'd be telling him, in effect, that this 'move' is not permitted.

Another way to say the same thing is that whether or not the earth is flat is not a matter to be settled by DEFINITION but by EMPIRICAL OBSERVATION. The earth's flatness is an hypothesis that is subject to verification or falsification. How does one verify or falsify an hypothesis? By 'looking and seeing', not by merely presenting a definition that makes the hypothesis true.

Similarly, what we are trying to demonstrate here is that the relationship between J/P and the other two variables (perference order and I/E) is ALSO an empirical matter. This means that one cannot simply say, 'but that's how I choose to define the terms'. One must give empirical evidence that P and only P can be attached as the fourth letter to iNf. One must SHOW that there is no such thing as an inFj, not simply DEFINE the inFj out of existence. To do the latter would be nothing more than a conceptual sleight of hand.

'But', somebody might say, 'if the iNfp exists, wouldn't we have already come across one? Wouldn't somebody have tested as an inFj on the MBTI?'. To this question we'd reply that you do in fact come across such people all the time, but don't know it. And you don't know it because the way the MBTI is constructed the inFj will mistakenly be identified as an INFJ (ie, an 'iNfj'). This is so because preference order is not tested independently by the MBTI, but rather INFERRED from the J/P score in combination with the I/E score.

To clearly see this, consider the following. If Mike, an imaginary subject, scores as an INFP on the MBTI, how do we know what his 'preference order' is? Having scored INFP simply means four things - that Mike scored

1. higher in I than E,
2. higher in N than S,
3. higher in F than T, and
4. higher in P than J.