The predictive patterns of language and decoding skills are different for

bilingual than for monolingual learners

The results from Study 3 found the prediction of linguistic skills and decoding for reading comprehension to be equal across the early bilingual and monolingual readers, F (5.0) = 0.555, p = 0.734. In spite of extensive searching, Grant et al. (2011) was the only identified study of pre-adolescent early bilingual learners that examined how L2 skills predicted L2 reading comprehension. However, that study examines bilingual first 3^rd graders with larger vocabulary gaps than was the case for the early bilingual 5^th graders in Study 3. Differences in the samples might explain the differences in the results. Study 3 found that the linguistic variables predicting reading comprehension were the same

across language groups, and Grant et al. (2011) found a deviating pattern.

In Grant et al. (2011), decoding predicted reading comprehension for both groups, and vocabulary predicted reading comprehension for bilingual first children. Interestingly, the results of Grant et al. (2012) are similar to those of several studies of minority language learners indicating differences in predictive patterns for reading comprehension across language groups (Burgoyne et al., 2011; Droop & Verhoeven, 2003; Geva & Farnia, 2012; Hutchinson et al., 2003; Limbird et al., 2014). These studies represent a mix of methods, including both studies using latent variables in SEM analysis and those using sum scores in multiple hierarchical regressions. The gap in the instructional language levels also varies across the samples of these studies. The gap varies from a smaller gap than was found in the present thesis to a larger gap than was identified in the bilingual first sample of Grant et al. (2011).

Furthermore, the participants’ age also varies. Hence, it is difficult to detect any reason why some studies of bilingual learners find equal predictive patterns (Babayiğit, 2015; Proctor et al., 2012), in line with the present study examining early bilingual learners, thereby indicating that the results could apply to bilingual learners in general, while others do not (Burgoyne et al., 2011; Geva & Farnia, 2012; Grant et al., 2011;

Hutchinson et al., 2003; Limbird et al., 2014).

Due to the lack of studies of early bilingual pre-adolescents examining the prediction of reading comprehension, it is difficult to determine how well the results of the present study can be generalized to other samples of early bilingual learners. Furthermore, the mixed results of studies of minority language learners provide no support in detecting a pattern that could explain differences in results across studies regarding predictive patterns of reading comprehension.

Regarding the magnitude of the prediction of linguistic skills to reading comprehension, the present study finds the model parameters examined in Study 3 to be equal. This contradicts hypothesis 4 in this thesis. The hypothesis was based on prior research indicating that linguistic skills

seem to play a more central role in reading comprehension for minority language learners than for monolingual learners (Hutchinson et al., 2003; Kieffer, 2012b; Proctor et al., 2012; Silverman et al., 2015). This is also the general trend in the systematic review of Proctor and Louick (2018) examining the impact of vocabulary on reading comprehension, although they point out the need for meta-analytic work to determine with certainty that vocabulary is a stronger predictor of reading comprehension for bilingual learners than for monolingual learners.

Hence, linguistic skills are likely a stronger predictor for reading comprehension for early bilingual learners. as well.

However, studies that have found that language is more crucial for minority language learners have often examined growth (e.g., Kieffer, 2012b; Proctor et al., 2012; Silverman et al., 2015). Hence, rather than differences in concurrent prediction, it is possible that linguistic skills play a superior role in the growth of reading comprehension for bilingual learners than for monolingual learners. An equal magnitude of concurrent prediction of linguistic skills for reading comprehension is supported by prior research using SEM modelling to test this relationship (Babayiğit, 2015; Proctor et al., 2012). Such models have the advantages of testing whether different regression coefficients actually are significantly different from one another, which ordinary multiple regression and hieratical regression cannot do (R. B. Kline, 2015). The results of the present thesis therefore conflict with hypothesis 4. The early bilingual learners in Study 3 do have lower language levels than their monolingual peers; however, this gap did not result in different magnitudes of the regression coefficients of linguistic skills to reading comprehension.

Regarding the predictive relationship of linguistic aspects to reading comprehension, listening comprehension had the largest impact on reading comprehension. Listening comprehension explained 26.01% of the variance in reading comprehension. This finding is in contrast to most other studies, which have identified vocabulary as the main variable to

predict L2 reading comprehension in minority language learners (Droop

& Verhoeven, 2003; Hutchinson et al., 2003; Kieffer, 2012b; Leider et al., 2013; Proctor et al., 2012; Silverman et al., 2015). However, in the present study, the relationship between vocabulary and reading comprehension was not significant (p = 0.872). Text cohesion vocabulary explained an additional 18.49% of the variance in reading comprehension. This is in line with Rydland et al. (2012), who also examined the reading comprehension of 5^th grade bilingual learners. The results of the present study must be interpreted with caution. Despite the use of invariant latent variables, the dimensionality of the latent construct has not been tested. Hence, several of the latent variables might be better represented by merging them into one underlying language ability. In fact, most studies that have examined the specific impact of different linguistic subskills have not tested the dimensionality of the constructs used in regressions (e.g., Burgoyne et al., 2011; Geva & Farnia, 2012;

Hutchinson et al., 2003; Leider et al., 2013; Rydland et al., 2012). Thus, little is known about whether some constructs truly explain more L2 reading comprehension than others. To truly examine this issue, it would be critical to examine whether a one-factor model, a correlated model and a bifactor model differed significantly from one another.

Taken together, the results of Study 3 do not support hypothesis 4 of this thesis.