Addressing the question of why some children manage to continue successfully through the later stages of literacy acquisition while others are unable to meet the challenges presented by fourth and fifth grade reading tasks, an 18-month, in-depth study was conducted of the home environment factors influencing the reading comprehension of second, fourth, and sixth grade students. Analysis of the data, based on interviews with family members, students' reading scores, and in-class observations of student behavior, indicated that word recognition and vocabulary were influenced by the cognitively enriching activities some homes provide, and related strongly with children's time with adults rather than with other children or watching television. Reading comprehension, though not unaffected, was less powerfully dependent on such enrichment, but was related to the emotional climate in the home. More than word recognition or vocabulary development, reading comprehension appeared to require complementary supports from home and school--the positive self-concept that develops in an emotionally positive home and the direct instruction and skill practice offered by the school. The emotional climate of the home also related closely to the students' word production in writing tasks. (MM)