Preventing reading failure in young children with phonological processing disabilities: Group and individual responses to instruction
Torgesen, J. K., Wagner, R. K., Rashotte, C. A., Rose, E., Lindamood, P., Conway, T., Garvan, C. (1999) Journal of Educational Psychology, 91(4), 579-593. doi.org/10.1037/0022-0663.91.
The relative effectiveness of three instructional approaches for the prevention of reading disabilities in young children with weak phonological skills was examined. Two programs varying in the intensity of instruction in phonemic decoding were contrasted with each other and with a third approach that supported the children’s regular classroom reading program. The children were provided with 88 hours of one-to-one instruction beginning the second semester of kindergarten and extending through second grade. The most phonemically explicit condition produced the strongest growth in word-level reading skills, but there were no differences between groups in reading comprehension. Word-level skills of children in the strongest group were in the middle of the average range. Growth curve analyses showed that beginning phonological skills, home background, and ratings of classroom behavior all predicted unique variance in growth of word level skills.
This study was designed to contribute to our understanding of the instructional conditions that need to be in place to prevent reading disabilities in young children. Both the specific design of the study and the questions it addressed were derived from previous research and theory in two areas. The broadest context of the study is the new understanding of reading and reading disabilities we have acquired from research over the past 20 years (Adams, 1990, Metsala & Ehri, 1998), and the more focused context is previous research on instructional methods that accelerate reading development in young children who are either experiencing, or are at-risk for reading failure (Foorman, Fletcher, Francis, Schatschneider, & Mehta, 1998; Shanahan & Barr, 1995; Wasik & Slavin, 1993; Vellutino, Scanlon, Sipay, Small, Pratt, Chen, & Denckla, 1996).
Within the broader context, perhaps the most important single conclusion about reading disabilities is that they are most commonly caused by weaknesses in the ability to process the phonological features of language (Liberman, Shankweiler, & Liberman, 1989). In particular, individual differences in phonological awareness and rapid automatic naming ability have been shown to exercise unique causal influences on the rate at which children acquire important early reading skills (Wagner, et al., 1997). These two cognitive/linguistic abilities have also been demonstrated to be the most salient disabilities of older children with reading disabilities (Fletcher, et al., 1994; Wolf, 1997).
Discoveries about the core cognitive/linguistic problems of children who experience special difficulties learning to read are important to research on the prevention of reading disabilities for two reasons. First, they provide a means to accurately identify children at-risk for reading disabilities before reading instruction begins (Torgesen & Burgess, 1998). This should allow preventive work to begin earlier in school and focus accurately on children who are most in need of preventive intervention. Second, use of selection criteria involving phonological skills allows identification of a more theoretically coherent sample for study than is frequently the case. Most previous research has focused on children identified for intervention by teacher nomination or socio-economic status (Wasik & Slavin, 1995). While children
identified in this manner clearly constitute an “at-risk” group (Bowey, 1995), they are not as cognitively or linguistically coherent as groups identified by specific deficiencies on linguistic measures. The goal of the present study was to examine the effectiveness of several instructional procedures for a specific subset of children who are at-risk for reading difficulties; those who enter school delayed in the development of phonological skill.
The most important impact of weaknesses in the ability to process phonological information is to make it very difficult for children to understand and apply the alphabetic principal in deciphering unfamiliar words in print (Siegel, 1989; Torgesen, in press). These early difficulties in acquiring phonemic decoding skills lead directly to delays in the development of orthographic reading skills which are one important basis of fluent reading (Ehri, 1998; Share & Stanovich, 1995). Children with reading disabilities show word-level reading problems from the beginning of reading instruction, and in the normal course of development, they almost never acquire average level skills in this area (Francis, Shaywitz, Stuebing, Shaywitz, & Fletcher, 1996; Juel, 1988).
Evidence about the central role of word-level reading problems in children with phonetically based reading disabilities suggests that, to be successful with this population, interventions must contain powerful instruction and effective practice at this level. Consistent with this implication, two recent reviews of early intervention research using broadly defined samples of children concluded that the most successful programs to date have included systematic instruction to help children learn to decipher words in print (Pikulski, 1994; Wasik & Slavin, 1993). One study in particular (Iverson & Tunmer, 1993) provided specific evidence that the effectiveness of an early intervention program for at-risk children could be enhanced substantially by the addition of explicit instruction in phonemic decoding skills. However, both reviews also concluded that the most successful interventions were those that were derived from the most inclusive models of reading and which contained an appropriate balance of word and text level instruction, including instruction specifically focused on reading comprehension. Thus, previous research with children identified by teacher nomination or socio-economic status suggests that, to be maximally effective, early intervention programs need to contain a carefully orchestrated mix of instruction to help children construct the meaning of text as well as to read words accurately and fluently.
A potential tension between the needs for instruction designed to build word reading skills and instruction focused on construction of meaning is brought into sharp focus by two recent, carefully controlled prevention studies. Brown and Felton (1990) contrasted two instructional approaches with a sample of children selected because of weaknesses in phonological development, and Foorman and her colleagues (Foorman, et al., 1998) contrasted three instructional approaches with first grade Title 1 children. In both cases, the instructional condition that contained the most explicit instruction in phonemic decoding skills produced the strongest growth in word-level reading skills, and the Title 1 study also showed parallel differences in reading comprehension across groups. Of particular interest in the present context is the fact that both studies also showed that explicit and systematic instruction in phonemic decoding skills was particularly beneficial for those children who were most impaired in phonological awareness at the beginning of the study. This suggests that, as children’s phonological weaknesses become more severe, their need for explicit instruction in word-level skills increases. If the time available for preventive instruction is limited, as it almost always will be, what is the most
appropriate balance of instruction for children with severe phonological weaknesses?
In the present study, the most important instructional contrast involved the degree of explicitness of instruction in phonological awareness and phonemic reading skills as well as the extent of decontextualized, focused practice on these skills. Both instructional approaches included in the study were based on the idea that children with phonological processing weaknesses must receive direct instruction in phonemic decoding strategies. However, one approach attempted to create maximum possible strength in phonemic decoding (within the constraints of the amount of instructional time available), while the other approach emphasized the active coordination of less well developed phonemic reading skills with clues from context as a means of accurately reading words in text and constructing meaning. The latter approach was more fully “balanced” in its mix of word and text level instruction.
These two experimental interventions were contrasted with a third intervention that was designed to be more closely coordinated with each child’s classroom reading instruction than the other two interventions. This study employed one-to-one tutorial intervention, which is widely regarded as being the most powerful form of instruction for at-risk children (Learning First Alliance, 1998). Furthermore, it makes sense that tutorial instruction that is closely coordinated with the reading instruction the child receives in the regular classroom should have some advantages over instruction that is not coordinated in the same way (Allington & McGill-Franzen, 1989). However, it is also likely that the effectiveness of tutorial instruction will depend upon the nature of the classroom instruction with which it is coordinated. If the classroom instruction contains sufficient elements that are responsive to the needs of children with phonological processing weaknesses, and the tutorial instruction is able to reinforce and explicate this instruction for individual children, outcomes are likely to be better than when the classroom instruction is not specifically responsive to the needs of at-risk children.
One final aspect of the present study derives from the manner in which previous early intervention programs have been evaluated. Typically, these programs have been compared to alternative methods, and found to produce substantially greater gains in reading (Hiebert, Colt, Catto & Gury, 1992; Pinnel, Lyons, Deford, Bryk, & Seltzer, 1994). However, because standardized measures of reading skill are frequently not reported, we often do not know whether student reading skills were in the average range following instruction, or whether they were better than the control group, but still seriously behind in reading. Even when standardized scores are in the average range, individual variability in scores is not explicitly reported, so that it is not possible to determine the effectiveness of the intervention for the most impaired children. Since previous studies have typically selected their samples from the 15 30% most at-risk children, it is clearly possible that overall effects are largely the result of improvements in reading skill among the least learning impaired children. In the present study, we used standardized measures of reading skill to assess overall level of reading outcomes, and we also separately examined performance of our weakest children. The study also employed growth curve methodology to provide information about characteristics of the children who were least responsive to instruction.