Why does Labov have such weird transcriptions?

It is the experience of many linguists, when they crack open something written by Bill Labov, or his students, that they suddenly realize they are using a transcriptional system that they are probably not used to. Sure, the symbols <i> and <e> look familiar, but when you realize they correspond to the IPA symbols <ɪ> and <ɛ>, you might start to feel uneasy. The worst offender, though is <oh>, which is the vowel that appears (in some dialects) in thought, lost, law. What is that? Why is there an <h>in there? Why isn't he just using IPA??

What are these symbols?

The Labovian transcriptions has the following symbols, (presented with the corresponding Wells' Lexical Set).

These symbols were largely adopted from Trager & Bloch, and as they outline in the ANAE, apparently had some widespread usage in American dialectology & phonology in the early 20th century. Trager & Bloch developed this system largely to make a phonological argument about English: Contrary to commonly held belief, English only has 6 vowel phonemes! The details of that analysis isn't too important, but what does matter is that each "subsystem" forms a natural class of sorts. 

Why not use IPA?

Well, I think there's a good reason. To begin with the simplest answer, in sociolinguistics, we often need to make reference to categories more abstract than phonemes. The Labovian notation is actually a diaphonemic one, and the use of IPA symbols, as they're conventionally understood, wouldn't be quite accurate. For example, what's the IPA symbol for the vowel that appears in cat? The obvious answer would probably be /æ/. But let's look how that vowel is distributed in the Atlas of North American English.

The proper IPA transcription for the word that appears in cat seems to vary between [a̠~a~æ~æ̝~ɛ̞]. Ok, well, that's in the narrow transcription, you say. In the broad transcription, it would be /æ/. But still, I say it's not so clear cut. Looking at the relationship between vowels in the Inland North, I don't really think it would be correct to give the vowel in cat the broad transcription /æ/.

We could give the Inland North its own phonemic analysis, and give cat something like /ɛː/ in broad transcription, but we would start to seriously befuddle ourselves doing cross dialectal comparisons. Or even intra-dialectal comparisons, if you're doing a study like Monica Nesbitt, tracking the reversal of the Northern Cities Shift.

Why not use Lexical Sets?

So, there is a system of denoting "word classes" in a way that could avoid diaphonemic confusion: Wells' Lexical Sets. Using Wells' Lexical Sets, we could say that across North America, the word cat has the Trap vowel. This label, Trap, denotes a class of words that have a common linguistic history such that they often have a common phonemic incidence in contemporary dialects. So, regardless of what the phonemic analysis of the Inland North really is,  cat has the same vowel as hat as sad as mask, etc.

If we could use a lexical set system this way, why don't we? The answer from the Atlas of North American English is that lexical sets are insufficiently structural. For example, what is the phonological relationship between Fleece, Kit, Face and Dress?  Well, as far as the transcription system goes, these are just lists of word classes, with no particular phonological relationship implied except that they're not the same vowel.

In the Labov/Trager/Bloch system, these vowels are represented as /iy/, /i/, /ey/, and /e/. The transcriptional system is now encoding a phonological analysis. Because /i/ and /e/ are single characters, they are short vowels. Because /i/ and /iy/ share a character, they share a height and backness specification.

Essentially the system constructs a systems of analogous contrasts. As /iy/ is to /i/, so /ey/ is to /e/. And as /iy/ is to /ey/, so /i/ is to /e/.  In a sense it's a very stripped down feature system encoded in the transcription.

Ok by WHY is <oh> that way!?

Well, ok. This part was inherited from Trager & Bloch, and was then kind of screwed up by the push to eliminate special characters from the system. It makes enough sense to transcribe the Lot class as <o> . First off, in British English and some North American dialects this vowel is rounded. Secondly, most words in the class are spelled orthographically with <o>.

Next, Trager/Bloch/Labov decided to represent a long and ingliding vowel as ending in <h>. That's because they were trying to define all non-short vowels as ending in a glide, and with /y/ and /w/ already claimed, /h/ remained.

In the phonological analysis of Lot and Thought, Thought minimally contrasts with Lot in terms of this /h/ glide, so it gets <oh>.

The real problem is <ow>! In the phonological analysis, /ow/ does not share height and backness with /o/. The low back vowel with a /w/ glide is /aw/. If the Labovian system hew more closely to the Trager & Bloch system, it would represent the Goat vowel as /ʌw/ (they represented it as /əw/). But, one principle Labov strove for was "minimum deviation from Roman typography" (Labov et al 2006, a.k.a. ANAE).

Which system should be used?

To be honest, I think all three transcriptional systems ought to be engaged, so long as they are properly indicated. I think the Labov/Trager/Bloch system forces viewing the vowel system of various dialects with a certain systematicity that is clarifying. An IPA transcription is necessary for the phonetic detail, which is not clearly communicated with simple formant values. Finally, when speaking to an audience, I think you should always use the Wells' lexical sets.

If you did a study analyzing variation in (Labovian notation now) /i/ and /e/ varied, I think the following two ways of saying them are confusing:

• I found an effect for [aɪ] but not for [iː].
• I found an effect for [ɪ] but not for [ɛ].

The first option could confuse people into thinking you were analyzing /ay/ and /iy/. The second option is going to be perceptually difficult, if only because English doesn't allow stressed lax vowels. People won't be confused about which two vowels you're talking about if you say:

• I found an effect for Kit but not for Dress.