Text complexity and word learning

Vocabulary knowledge is a critical factor in reading comprehension. Although attention has been widely given to vocabulary acquisition in the early stages of schooling, as well as in a L2 learning context, research regarding L1 vocabulary growth in higher school grades is relatively scarce. Consequently, direct and explicit guidance on specific words learning strategies are virtually abandoned after primary school, L1 vocabularies being relegated to incidental learning through independent reading. Yet incidental learning accounts for low retention rates (Hulstijn et al., 1996) and little is known about which text features should be considered in order to facilitate students’ word learning (Scott, 2005). Conversely, reading comprehension only takes place if the percentage of known words in a text is 98% (Nation, 2001).
This paper presents the results of an on-going experimental study hypothesising about the influence of text complexity in L1 word retention. It is assumed that the helpfulness of text context towards word retention depends on (i) low density of unknown words in the local context; (ii) low co-occurrence of subordinate clauses and other embedded structures; (iii) co-reference (Martins, 2012).160 9th grade students of Portuguese (L1) attending Portuguese public schools are randomly assigned to two condition groups. The experimental condition group read a simplified informational text; the control condition group read a highly complex text. Marginal glosses of 20 target words are provided in both texts, along with glosses of non-target words. A pre-text and post-test addressing the target words are delivered before and after the treatment applied to both groups. Results for meaning accuracy delivered in the post-test are measured using a T-test for unpaired samples.
This study aims at contributing to the knowledge of the textual determinants facilitating vocabulary acquisition and suggests generalisations about textbooks writing procedures.