This study was designed to determine (1) the relevance of a child's "language map"--his expressed attitude toward reading as developed by early experiences with reading material and oral reading--to his potential reading achievement and (2) the accuracy of a previously developed instrument for measuring the "language map" and thus the semantic constructs of young children. The Individual Reading Interest Survey (IRIS) was given to 52 rural, disadvantaged children who were beginning the first grade in Florida and to a stratified sample of 143, 3-, 4-, and 5-year-old children in a University of Georgia project. The 42 IRIS questions were constructed to reveal the child's knowledge of and interest in reading. The Metropolitan Achievement Test (MAT) and the Metropolitan Readiness Test (MRT) were given to the 6-year-olds and the Wide Range Achievement Test to the younger children. Although the MAT and MRT scores were most closely correlated, there was a significant correlation between the IRIS and other tests for 5- and 6-year-olds. Preliminary generalizations also concluded that the measure of children's "language maps" was reliable. Tables and references are included. (BT)