Ed, your definition of T-unit is about as close as you can come. It's an independent clause with all its subordinate clauses and all its nonrestrictive modifiers, regardless of punctuation. So a modifier punctuated with a capital letter and period will be included in the T-unit it attaches to. There will be, here and there, a "garble," a constituent you can't attach. And from time to time, especially in student papers written in class, you'll add a finite verb-if two counters agree that the student left it out accidentally. Usually you can tell whether a student is writing ill-formed constituents or whether she just omitted a verb because of the rush of time. You see that sort of omission on emails all the time nowadays. Remember that Kelly was concerned with a measurable, definable unit. He had gone through all the research to the mid sixties and found none that successfully defined sentence or could capture what happened syntactically between 4th and 12th grade. Sentences clearly get longer, but how? And 4th graders can write surprisingly long sentences by just compounding short clauses. "We went to the store and Mommy bought some peanut butter and we went home and Mommy made me a sandwich and . . . ." Kelly needed a way to differentiate a 12th grader's sentence length from a 4th grader's. Earlier researchers had identified subordination ratios: they knew that 12th graders used more subordinate clauses. But they were stuck at that point because of their definition of sentence. Kelly's genius was to see that the sentence couldn't be delimited, that he needed a grammatically definable unit to capture the syntactic growth that took place in the 8 years between 4th and 12th grade. Hence the T-unit (a minimal terminable unit). The beauty of the T-unit is that it captures the growth in clause length as well as the subordination ratio. In fact, a T-unit's length is clause length x subordination ratio. That was exactly his explanation of what made T-units grow: as students grew older, they wrote longer clauses and used more of them. The major difference between 12th graders and "superior adult" writers was that the clause length of professional writers increased, not their subordination ratio. Kelly came to regret that he had ever used the terms "maturity" and "superior." He didn't mean the terms in the way they came to be taken. Too value laden. I think you'll find, Ed, that T-unit length will vary greatly from text to text, within the same magazine, even within the writing of one individual. It's just a way to define a certain kind of syntactic ability that develops in the writing of students during the school years. And it's only valuable when you're measuring large groups. Kelly and Francis Christensen had a running argument about how to measure such growth (Kelly had a paragraph or two on that in, I think, his 1964 NCTE research monograph). In essence, though, they were talking about similar phenomena but using different terminology. Christensen talked about professional writers using cumulative sentences, sentences with lots of free modifiers. Hunt talked about professional writers using longer clauses. When you realize that most free modifiers (participial phrase, absolutes, etc.), since they are phrases (that is, they have no finite verb), will be counted in the length of the independent clause they are attached to and will pump up clause length considerably, you realize that Kelly's clause-length measurements would capture that use of free modifiers. Christensen had more of a prejudice toward narrative writing, which gives you lots of free modifiers. Kelly's measurements were more neutral. Business and academic writing, with lots of nominalized phrases, will also pump up clause length. Of course, Christensen abhorred long noun phrases. I don't think Kelly used them very much in his own writing (his style was always clear and readable). But he was aiming to do different things in his research from what Christensen was aiming to do. Kelly wanted to describe certain kinds of syntactic growth, statistically. He did just that. And he gave us useful insights into what happens to the written syntax of students as they move through school. He was more of a grammarian than a rhetorician. He laid the foundation for sentence combining, because he saw the growth as being based on the principles of early generative grammar (which he was very much influenced by). He wrote an article called "How Little Sentences Grow into Big Sentences." And he gave dozens of presentations on the same topic throughout the country. I don't know if I've answered all your questions, Ed. Actually, I'm glad you gave me a reason to remember a part of my life and career very dear to me. Kelly Hunt was a gentleman of the old school, always kind and generous to his colleagues and students, even a graduate student who fell into grammar accidentally from literature and took a long time learning to love grammar and statistics. Well, actually that graduate student never learned to love statistics, though for a brief period of his life he could differentiate t-tests from chi-squares. I hope this has been useful. Max