Word Identification Strategy (DISSECT) provides challenged readers with a functional and efficient strategy to successfully decode and identify unknown words in their reading materials. The strategy is based on the premise that most words in the English language can be pronounced by identifying prefixes, suffixes, and stems, and by following three short syllabication rules. In the research study, the students made an average of 20 errors in a passage of 400 words prior to learning this strategy. Having learned the Word Identification Strategy, students reduced their errors to an average of three per 400 words. Reading comprehension increased from 40% on the pretest to 70% on grade-level passages.
The Word Identification Strategy used in SIM was developed by Lenz and Hughes (1990) and initially tested on 12 middle school students with learning disabilities. This strategy is intended to help struggling readers decode and identify unfamiliar words, and is based on the common underlying structure of most polysyllabic words in English. Most of these words can be pronounced by identifying the components of the words (prefixes, suffixes, and stems) and then applying three syllabication rules to the stem word. In this approach, prefixes and suffixes are loosely defined as recognizable groups of letters that the student can pronounce.
As described by Lenz and Hughes (1990), there are seven steps to identifying an unknown word. The steps are remembered using the first-letter mnemonic, DISSECT:
Step 1: Discover the context. This step requires the student to skip over the unknown word and read to the end of the sentence. Then, the student uses the apparent meaning of the sentence to guess what word might best fit. If the guess does not match the unknown word, the student moves on to the next step.
Step 2: Isolate the prefix. In this step, students look for a pronounceable sequence of letters at the beginning of the word. Students are taught a list of prefixes to facilitate recognition. If a prefix is identified, the student draws a box around it to separate it visually from the rest of the word (for example, in the word inactivity, the "in" would be boxed; in underachievement, the "under" would be boxed).
Step 3: Separate the suffix. Using a procedure similar to Step 2, the student boxes off the suffix, if there is one (in the word inactivity, the "ity" would be boxed; in underachievement, the "ment" would be boxed).
Step 4: Say the stem. The student attempts to pronounce the stem (activ, achieve). If the stem cannot be named, the student moves on to Step 5.
Step 5: Examine the stem. In this step, the student divides the stem into small, pronounceable word parts, using the Rules of Twos and Threes (Lenz & Hughes, 1990, p. 151). The rules can be summarized as follows:
Rule 1: If the stem or part of the stem begins with a vowel, separate the first two letters; if it begins with a consonant, separate first three letters; continue to apply this rule until the end of the stem is reached (ac\tiv, ac\hie\ve).
Rule 2: If you cant make sense of the stem after using Rule 1, take off the first letter of the stem and use Rule 1 for the remainder of the stem (a\chi\ev\e).
Rule 3: When two vowels are together, use what you know about pronunciation (for example, pronounce two adjacent vowels as a single sound, and remember that a final e following a consonant is usually silent) and try the different possibilities (a\chiv, a\chev).
Step 6: Check with someone. The student checks with a teacher, parent, or other person.
Step 7: Try the dictionary. The student looks up the word, uses pronunciation information to pronounce the word, and, if the word is unfamiliar, reads the definition.
Lenz and Hughes (1990) recommend that the strategy be fully employed only for those words that are most critical to understanding a passage of text, such as a word in a chapter heading. Bryant, Vaughn, Linan-Thompson, Ugel, Hamff, & Hougen (2000) note that this strategy works best when the word being analyzed is one that is already in the students listening vocabulary.