Relationship Between Single Word Decoding and Reading Comprehension Skill

Charles A. Perfetti and Thomas HogaboamLearning Research and Development Center and Department of Psychology,University of PittsburghChildren classified as skilled and less skilled in reading comprehen-sion differed in vocalization latencies to single printed words. Over-all, vocalization latencies were shorter for the skilled group than theloss skilled group and there was an interaction between word typeand comprehension skill. The comprehension groups showed largevocalization latency differences for pseudowords and for low fre-quency English words, but smaller differences for high frequencyEnglish words. Knowledge of word meanings may be a less significantfactor in vocalization latency for the skilled group than for the un-skilled group. It is suggested that at least some unskilled compre-henders may have failed to develop automatic decoding skills andthat this failure may lead to diminished comprehension skills sharinga common processing capacity with nonautomatic decoding.The conceptualization of reading as com-posed of separable components allows morethan one view on the relationship betweenthe components. The cognitive componentsof reading can be considered as separableand independent or as separable and inter-dependent. As Guthrie (1973) has argued,the more tenable view for at least somecomponents is that they are interdependentand mutually facilitative.In the case of decoding and compre-hension, there are similar possibilities ofindependence and interdependence. For atleast some indicators of decoding, it seemsclear that decoding is not sufficient forcomprehension (Cromer, 1970; Wiener &Cromer, 1967). However, it does not followthat decoding and comprehension are in-dependent. Rather, reading comprehensiondepends on the availability of highly de-veloped skills, including the ability toconvert print into the language code.The required conceptualization of theThis research was supported by the LearningResearch and Development Center, which is sup-ported in part by funds from the National Insti-tute of Education.The assistance of Susan Goldman with variousstages of the research is acknowledged.Requests for reprints should be sent to CharlesA. Perfetti, Learning Research and DevelopmentCenter, 3939 O'Hara Street, Pittsburgh, Pennsyl-vania 15260.reading process is one that takes account ofthe fact that all basic processes carried outin a integrated behavior such as readingnot only interact with each other but alsomust share a limited capacity mechanism,at least in part. A mechanism which isheavily demanded by one process essentiallybecomes less available for other processes.Thus, if a reader requires considerableprocessing capacity to decode a single word,his processing capacity is less available forhigher order integrated processesfor ex-ample, memory for the just previouslycoded word may suffer, memory for thepreceding phrase may decrease, and thesubject's ability to "predict" what he is yetto encounter on the printed page maydiminish.There is evidence that skilled compre-henders have basic word skills that aresuperior to those of unskilled comprehenders.For example, Katz and Wicklund (1971)found differences between good and poorcomprehenders for a word-scanning task inwhich children had to decide whether atarget string of printed words contained apreviously presented key word. Good com-prehender s were faster at thi task thanwere poor comprehenders. However, in asimilar scanning task involving letters, Katzand Wicklund (1972) found no differencebetween reader groups. Thus, at least for461