The models of reading comprehension that have been explored thus far have been complex in their portrayal, reflecting the nature of reading comprehension itself. The simple view of reading (SVR) (Gough & Tunmer, 1986; Hoover & Gough, 1990) eschews this idea of complexity, proposing that reading comprehension is the process of just two contributing variables: word decoding (D), and linguistic comprehension (LC). This is further simplified in the presentation of the process of reading comprehension (R) as an equation, whereby:
R = D x LC
The equation depicts the multiplicative relationship between the two variables, that is, it is not possible for reading comprehension to exist without an ability to decode words
(regardless of their linguistic comprehension skills), and equally, reading comprehension is not possible without some ability to understand the words they have decoded, (regardless of how strong their decoding skills are). Consequently, when both decoding and linguistic comprehension are measured in their entirety, these two factors should explain up to 100 percent of the variance in reading comprehension.
In addition to the multiplicative model of the SVR (Gough & Tunmer, 1986; Hoover & Gough, 1990), research has suggested that the equation may be applicable as an additive model (Dreyer & Katz, 1992; Joshi & Aaron, 2000), thus:
In a study of elementary school-aged students, Dreyer and Katz (1992) found that the
evidence was stronger for a model based on the sum of the two variables of D and LC, rather than as a product of the two. Interestingly, however, results from a study conducted by Joshi and Aaron (2000) presented equal argument for both the additive and multiplicative formats of the SVR (presenting very similar levels of variance for each), with results from the same age children as the data supporting the additive model (Dreyer & Katz, 1992). Despite their findings, Joshi and Aaron (2000) recommended adopting the multiplicative model, on the basis that it is applicable to a broad range of reading skills, including making allowances for individuals who are non-readers. Regardless of whether the model remained with reading comprehension as a product or as a sum of the two variables, both studies (Dreyer & Katz, 1992; Joshi & Aaron, 2000) concurred that both D and LC are essential factors within the process of reading comprehension. Despite this proposed amendment to the SVR equation, the initial equation depicting reading comprehension as a product, rather than the sum of, decoding and linguistic comprehension has been used most frequently in research.
Support for the SVR has been provided through the description of two groups of children with reading comprehension difficulties. The first group includes individuals who present with word decoding difficulties but appropriate linguistic comprehension (e.g., Catts, Adlof, & Weismer, 2006), and the second group includes individuals who present with difficulties in linguistic comprehension despite an absence of word decoding difficulties, (e.g., Nation, 2005). Word decoding comprises the skills of print concepts, letter knowledge, phonemic awareness, phonics, and spelling, (i.e., skills required in visual, visual
phonological, and visual morphological mapping). This allows meaning to be derived effectively from the written word. Word decoding skills are generally assessed using measurement of single word and pseudo word accuracy and fluency. Key constituents of linguistic comprehension typically include skills that are shared with language, such as
semantics, pragmatics, vocabulary, and syntax. Linguistic comprehension is often assessed by using measures of listening comprehension.
The SVR has often been used as a theoretical model to explain children’s reading comprehension. For example, it formed the framework of the Rose Report (Rose, 2006), which was undertaken to review the teaching of early reading in the UK. Several earlier studies examined the applicability of the SVR to explain the process of reading
comprehension in children. Hoover and Gough (1990) tested its validity by conducting a longitudinal study with early elementary school-aged bilingual children (n = 254), assessing their word recognition (representing word decoding) and listening comprehension
(representing linguistic comprehension) skills. Results demonstrated that the SVR accounted for 72 to 85 percent of the variance in the children’s reading comprehension. Other research with children has demonstrated that the SVR accounts for anything between 40 percent and 80 percent of the variance in reading comprehension (Catts, Adlof, Hogan, & Weismer, 2005; Dreyer & Katz, 1992; Joshi & Aaron, 2000). These studies demonstrate that while in the early years children’s cognitive resources are predominantly consumed by the processes required in word decoding, this relationship changes in the later stages of reading, with
linguistic comprehension becoming the dominant variable in reading comprehension by grade eight (Catts, Hogan, & Adlof, 2005). This shift is apparent in a study of over 900 university students (Landi, 2010), whereby word decoding skills were found to make a much weaker contribution to reading comprehension (relative to linguistic comprehension skills) amongst this skilled group of adult readers. Older readers (such as those in higher education) are more likely to have established at least a basic level of word decoding skill. Linguistic
comprehension is therefore more likely to demonstrate larger deficits relative to word decoding amongst this older population.
The SVR has also been used to identify and describe the types of difficulties encountered in reading comprehension. Research using the SVR framework has
demonstrated the existence of individuals who present with strong decoding skills and poor comprehension, as well as conversely, individuals who present with poor decoding skills and strong comprehension skills (e.g., Catts et al., 2006; Catts, Hogan, & Fey, 2003; Nation & Norbury, 2005). This distinction is key in the educational context where the opportunity presents for educational practice to aid the individual in progressing in each component (Kendeou, Savage, & van den Broek, 2009), thus preventing reading comprehension failure.
Despite providing a simple explanation of the complex process of reading
comprehension, the SVR neglects to provide an explanation of the complex interaction of constituent skills that comprise the two variables of word decoding and linguistic
comprehension. The SVR has been criticised for its failure to explain the role of additional key variables such as vocabulary knowledge, the motivation and background knowledge of the reader, and speed of processing (Aaron, Joshi, Gooden, & Bentum, 2008). Further models of reading comprehension have utilised the SVR as a foundation to which they have added additional elements in an attempt to address such concerns about the SVR. For example, Joshi and Aaron (2000) developed the Component Model of Reading which included a speed aspect in the model, and Tunmer and Chapman (2012) modified the SVR model to
incorporate an additional vocabulary measure. Component models are described in further detail below.
2.2.5. Component models of reading comprehension