ACTUACIÓN ANTE SOSPECHA O CONFIRMACIÓN DE CASOS EN EL CENTRO

The relationship between vocabulary and comprehension is generally acknowledged. Tannenbaum, Torgesen, and Wagner (2006) cite early factor analytic research (Davis, 1944; Spearritt, 1972) which established word knowledge as key to reading comprehension. For Davis (1944), the basis of the finding was a factor analysis of nine skills underlying reading comprehension. Findings were that word knowledge and reasoning “…accounted for 89% of the variance in reading comprehension” (Tannenbaum, Torgesen & Wagner, 2006, p. 382). A re-analysis of the same data by Spearritt (1972) revealed four main factors namely; “word knowledge, drawing inferences from the content, following the structure of the passage, and recognizing a writer’s intent and tone” (Tannenbaum, Torgesen & Wagner, 2006, p. 382). Of the four, word knowledge was the best differentiated.

Over the years, there has been an increasing interest and massive investment in research on learners’ vocabulary knowledge with several tests being developed to measure it. This increasing interest in learners’ vocabulary knowledge stems from an acknowledgement of the existence of a relationship between vocabulary knowledge and reading comprehension and proficiency. Although the bulk of research that has consistently proven the existence of a relationship between vocabulary and comprehension has been within L1 contexts, the same holds true for all contexts, be they second language, third language or foreign language

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contexts. On the basis of extensive evidence derived from multiple sources of assessment data, Carver (2003) posits that the vocabulary knowledge and reading comprehension relationship is so strong that they can possibly produce perfect correlations. This is tantamount to regarding vocabulary as a proxy for reading comprehension.

Baumann (2005) cites, as evidence for the strength of the vocabulary comprehension relationship, the close relationship between vocabulary and IQ, test performance, results from early descriptive studies, several correlational and factor analytic studies, the close affinity between vocabulary and achievement tests, as well as the centrality of vocabulary to readability. What is of contention is the nature of the vocabulary-comprehension relationship. Is the correlation a product of a deeper variable? If not, which causes the other, or do they reciprocally affect each other? These debates are best articulated in the hypotheses that have been developed to explain the nature of this fluid relationship. A snapshot of these hypotheses and their relatedness to the present study follows as a way to justify a route to reading comprehension via vocabulary proficiency and access.

1.5.1 The Instrumentalist Hypothesis

The instrumentalist view posits a direct causal relationship between vocabulary knowledge and reading comprehension. Beck, McKeown and Kucan (2008) assert a robust correlation between word knowledge and textual comprehension. Vocabulary knowledge is an index to how well readers will read and comprehend texts (Armbruster, Lehr & Osborn, 2003). Laufer (1998, p. 1) in Golkar and Yamin (2007, p. 91) calls vocabulary "… the best single predictor of reading comprehension." For this reason 95% word-knowledge coverage proposed by Browne, Cihi and Culligan (2007) would guarantee textual comprehension without the aid of a dictionary, leaving only 5% unrecognized words’ meanings recoverable from their contextual use. Shen (2008, p. 135) asserts “… the threshold for reading comprehension is, to a large extent, lexical”, implying that lexical deficit hinders successful comprehension. Biemiller (2005) and Laufer (2000) both attest to the positive, predictive, causative, preconditional, and concurrent effects of vocabulary on comprehension. Correlations found between vocabulary knowledge and reading comprehension in different studies range from .30 to .80 which is significant considering the multiple factors that compete with vocabulary to influence comprehension.

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Tannenbaum, Torgesen, and Wagner (2006) note from a review of Snow’s studies that the correlation between vocabulary and comprehension increased as the learners’ grade levels got higher with the correlation among first, fourth, and seventh graders being .45, .62, and .69, respectively. The correlation is also manifest in studies Tannenbaum, Torgesen, and Wagner (2006) review, which manipulated the level of word difficulty in texts by either replacing some words with either the high frequency or low frequency words. Where replacements were done with High Frequency Words (HFW) reading comprehension was enhanced and where the replacement was done using low frequency vocabulary, comprehension was compromised. Although the hypothesis has the support of a voluminous body of research, its failure to acknowledge that the direction of the influence is not only unidirectional is its major limitation.

1.5.2 The Knowledge Hypothesis

Unlike the instrumentalist hypothesis, the knowledge hypothesis rejects a causal relationship between vocabulary and comprehension and rather asserts that both are affected by general knowledge of the world. The soundness of a learner’s cultural schema is what engenders comprehension. Put differently, subject matter knowledge and exposure determines both the vocabulary knowledge of the learner and text comprehension. Anderson and Freebody, (1981, p. 82) represent this position when they describe vocabulary and comprehension merely as “…the exposed tip(s) of the conceptual iceberg.” The two relate only as they share the same underlying foundation, subject matter knowledge.

The knowledge hypothesis relates closely to schema theory, where words are perceived as mere surface representations of the deeper conceptual representations in readers’ schemata (Bos & Anders, 1990; Elleman, Lindo, Morphy & Compton 2009). This makes vocabulary knowledge a proxy for a learner’s world knowledge. The hypothesis presupposes reading to learn where learners have mastered the art of reading and now use it to learn subject content since, according to Araújo, Folgado and Pocinho (2009), the more complex a text becomes, the more knowledge of the world is required. However, complete rejection of a causal relationship between vocabulary and comprehension is limiting as it underestimates the challenges learners may face in their textual understanding where they have both the concept and the label in their HL but do not have the label in the L2 in which the text is written.

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1.5.3 The Aptitude Hypothesis

As with the knowledge hypothesis, the aptitude hypothesis downplays a direct relationship between vocabulary and comprehension and attributes successful comprehension to “…superior mental agility” (Baumann, 2005, p. 121) or general verbal aptitude or intelligence. Nagy (2005) acknowledges the correlation between learners’ vocabulary knowledge test scores and reading comprehension test scores but denies that it is a causal one. He contends rather, that the relationship emanates from the two kinds of tests drawing on similar intellectual abilities or meta-linguistic awareness. The aptitude hypothesis implies that very little, if anything, can be done to enhance learner comprehension since one’s aptitude is largely inherent. This is in contrast to the instrumentalist hypothesis where the teacher can enhance textual comprehension by developing learner knowledge of the key vocabulary. It also differs from the knowledge hypothesis where activating or broadening a learner’s knowledge of the world would be a route towards textual comprehension.

1.5.4 Access Hypothesis

The access hypothesis builds upon the instrumentalist hypothesis by acknowledging a causal relationship between vocabulary and comprehension. It however, goes further to assert that the relationship is only to the extent that the vocabulary is within learners’ easy access and that access can be enhanced through practice (Shen, 2008). The extent of learner access to the vocabulary in the text is what leads to comprehension. Access is itself a measure of several attributes like fluency of lexical access, speed of word recognition, and speed of word retrieval from memory (Elleman, et al., 2009). Proper and accurate word meaning representation eases words’ accessibility and frees up the higher level cognitive processes required for comprehension. Conversely, where lower level aspects like vocabulary knowledge are not automatized, it results in impairment of higher level processes like comprehension. Only those words that the learners can access can be used for text processing and lead to comprehension. Automaticity of word knowledge and word reading is key to the effect vocabulary would have on comprehension. The access hypothesis adds a condition to the instrumental hypothesis, that of accessibility of the vocabulary. This is particularly important when reading in an additional language where practice is necessary to ensure access.

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1.5.5 By-product Hypothesis

Like the instrumentalist hypothesis, the by-product hypothesis sees a causal relationship between vocabulary and comprehension but asserts that “…development in vocabulary is a consequence-not a cause-of comprehension” (Curtis, 1995, p. 44). The causal relationship is still uni-directional but the direction of causality is reversed. In other words, the by-product hypothesis is the inverse of the instrumentalist view. It is through sufficient exposure to texts which learners can comprehend that their vocabulary repertoire grows. Vocabulary is seen as a natural result of reading comprehension. Krashen (1985) asserts that when learners are exposed to comprehensible input, the input will be sufficient to generate both vocabulary and language production.

1.5.6 Reciprocal Hypothesis

Limitations manifest in the hypotheses discussed led to the emergence of the reciprocal hypothesis. Nagy (2005) faults extant hypotheses for masking rather than clarifying the relationship between vocabulary and comprehension. While believing in the causal nature of the vocabulary-comprehension relationship, he contends that the causation is bi-directional rather than unidirectional. This led him to the reciprocal hypothesis, which posits a chicken and egg relationship between vocabulary and comprehension where each depends on the other for existence. Verhoeven and Leeuwe (2008) also ideate the relationship between vocabulary and comprehension as causally reciprocal.

From the hypotheses discussed above, there is a manifest lack of consensus on both the nature and direction of the vocabulary-comprehension relationship despite agreement that there is a relationship between the two. What is apparent is the complexity of this relationship; plausibly including varying degrees of causality and reciprocity (depending on the hypothesis). The relationship between vocabulary and comprehension remains both contentious and complex.

Vocabulary is a huge component of a language with English for example, running into millions of words. A lifetime within the classroom would not suffice to give attention to all the words there are in a language. This then necessitates the selection of part of a language’s vocabulary which, when accorded adequate explicit attention, would ensure learner proficiency in the language. The frequency with which words are used or appear in a

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language corpus, which is the next subject of discussion, is one useful criterion for determining the vocabulary to privilege in language teaching and learning.