A study investigated how knowledge of a word's meaning, phonology, and orthography influences who will become a poor reader and who will develop adequate skill. Subjects (38 students from a small Ontario, Canada, city) were selected in grade 2 for their poor reading ability and followed until they reached grade 4. Conditions were devised in which latency for naming single digits or letters presented on a computer screen were compared to naming latency for a target digit or letter when it was embedded in an array of symbols which were either relevant or irrelevant to the subsequent item to be named. Nine of the 38 subjects remained poor readers in grade 4. Findings suggest that no one difficulty will lead to the status of a poor reader; instead, early strength in semantic, orthographic, or phonological processes may help to develop reading despite other deficits. (Eight tables and two figures of data are included.) (RS)