Words: The total number of words in the student's revision.

W/MC: The total number of words divided by the number of main clauses. This is the roughly equivalent of Hunt's "Words per T-Unit." (Hunt's "T-Unit" is a main clause defined as including all its subordinate clauses. See "Defining the 'T-Unit.'")

CMC/TMC: The total number of compounded main clauses divided by the total number of main clauses. 

TSC/MC:  The total number of subordinate clauses divided by the number of main clauses. One hypothesis is that subordinate clauses develop before "advanced" constructions such as gerundives (participles) and appositives.

W/SCL1: The total number of words in level one subordinate clauses, divided by the number of level one subordinate clauses. Theoretically, this number should grow before reductions to gerundives and appositives begin to blossom.

L2+SC/MC: The total number of subordinate clauses that are embedded within other subordinate clauses: "We saw the boy [who was reading the book [that you recommended.]]"

% W in PP: The number of words in prepositional phrases divided by the total number of words.

Passive F Verbs: Passive Finite Verbs. Because the Aluminum passage describes a process, one obvious question is the extent to which students used passive verbs.

Compounds: An obvious question is the degree to which students used simple compound (rather than subordinating structures) to combine sentences. MC = Compound Main Clauses; Subjects = Compound Subjects of finite verbs; F Verbs = Compound Finite Verbs; Complements = Compound Complements (Direct Objects, Predicate Nouns, or Predicate Adjectives). Fragments (Frag), Comma Splices (CS), and Run-ons (RO) are also counted here because they probably reflect attempts at compounding main clauses.

Level 1: These numbers reflect the total number of subordinate clauses embedded at different levels. See "L2+SC/MC" above.

Branching -- Left, Mid, and Right: Left branching constructions appear before the subject and verb in the clause in which they are embedded. In mid branching, the construction appears between the subject and verb, and in right, it appears after:

Left: [When Sarah saw Bill,] he left.
Mid: Bill, [when Sarah saw him,] left.
Right: Bill left [when Sarah saw him.]

Delayed Subject: Aan empty "it" usually fills the normal subject slot, and the meaningful subject is delayed until later in the sentence: "It is interesting that the delayed subject is not often discussed by traditional grammarians."

Appositive: A construction in which the syntactic connection is established by identity of meaning: "Aluminum, a metal, is abundant and has many uses."

Semi-Reduced Subordinate Clause: A Subordinate clause from which (usually) the subject and the auxiliary verb have been deleted. "When it is put through several other processes, it yields a chemical." --> "When put through several other processes...."

DO Ellipsed (Infinitive): A concept based on transformational theory which replaces the objective and subjective complements of traditional grammar. It is most often seen in sentences such as "They elected Bill president." in which "Bill president" is considered a nexus based on an ellipsed "to be." The infinitive phrase (with its subject, complement, and modifiers, is the complement of the finite verb. (Note the similarity to "They wanted Bill to be president.")

NuA: Noun Used as an Adverb

RCm: A retained complement after a passive verb.

Dr A: Direct Address

PPA: A Post-positioned adjective. This construction appears to be a late-bloomer based on the reduction of a subordinate clause -- "He was an old man, who was tired and fragile." --> "He was an old man, tired and fragile."

Noun Absolutes: This construction usually consists of a noun modified by a gerundive.