This paper reports the results of a behavioral anchoring analysis of the Iowa Tests of Basic Skills (Form G, Level 12) vocabulary (41 items) and reading comprehension (56 items) tests. Subjects were 82 sixth-grade students enrolled at the Carterville (Illinois) Grade School. More specifically, a curriculum-referenced interpretation of the ability levels is provided via definition of the characteristics of vocabulary items' stem words and, for the reading comprehension test, via definition of reading tasks and material that most students at different ability levels process successfully. The Rasch model was adopted for the analysis. For each test, anchor points on a continuum of ability levels were selected for analysis. Vocabulary items that discriminated between anchor points were batched and analyzed in terms of the stem words' frequency, distribution, abstractness, and part of speech. Reading comprehension items that discriminated between anchor points were batched and analyzed in terms of their relation to the structure of the text and the reader's prior knowledge. Results indicate a paucity of items that proved to be good discriminators. Reading should not be viewed as a listing of discrete subskills that must be independently measured. A table and four figures conclude the document. (TJH)