Dimensionality of Morphological Knowledge—Evidence from Norwegian Third Graders

Abstract

This study aimed to determine the dimensionality of morphological knowledge by examining different sources of variance. According to the Morphological Pathways Framework (Levesque et al., Journal of Research in Reading, 44, 10-26, 2021), morphological awareness, morphological analysis and morphological decoding are related, but distinct dimensions of morphological knowledge. However, multidimensionality might also stem from construct-irrelevant variance due to methodological artifacts. We assessed 612 Norwegian third graders on five measures of morphological knowledge and one measure of general vocabulary. Fitting a series of confirmatory factor analysis (CFA) models, we evaluated the dimensionality of morphological knowledge both within and across the five tests. Furthermore, we fitted three structural equation models (SEMs) to explore how different conceptualizations affect the relationship between morphological knowledge and general vocabulary: a five-factor model, a bifactor model, and a higher-order model representing morphological awareness, morphological analysis and morphological decoding. CFAs supported a multidimensional view of morphological knowledge and highlighted the need to account for construct-irrelevant variance. SEM analyses further illustrated that construct-irrelevant variance introduces a confounding element to the relations between morphological knowledge and vocabulary in the test-specific five-factor model, as only the bifactor and higher-order models separate between construct-relevant variance and variance due to methodological artifacts. The bifactor model is useful for separating sources of variance, especially during test development. For research purposes, however, we recommend conceptualizing morphological knowledge in line with Levesque et al., Journal of Research in Reading, 44, 10-26, 2021, to increase knowledge of morphological dimensions and their relations to other areas of literacy.

Mechanisms in the relation between morphological awareness and the development of reading comprehension.

“…Other advances could be made with measurement. Although modeling confirms the separability of these constructs (e.g., Kristensen et al, 2023;Levesque et al, 2017Levesque et al, , 2019, our tasks were not perfectly parallel between our constructs of morphological awareness, analysis, and decoding. This decision was driven by a pragmatic need to use reliable measures that we could have confidence captured the constructs of interest.…”

“…These findings also confirm the relevance of theoretical conceptualizations of morphology as multidimensional (Levesque et al, 2021), particularly in understanding its connections to the development of reading comprehension. There is increasing interest in dissecting the key factors within the broader construct of morphological skills (e.g., Goodwin et al, 2017; Kristensen et al, 2023; Levesque et al, 2017; Spencer et al, 2015; Tighe & Schatschneider, 2015). Critically, we show that morphological awareness in Grade 3 contributed to unique gains in both morphological analysis and morphological decoding from Grade 3 to 4, after substantial controls.…”

“…In these ways, morphological decoding and analysis are candidate mechanisms by which morphological awareness could help children with complex words which could in turn support them in understanding texts. There is growing empirical support of their distinctiveness (e.g., Kristensen et al, 2023; Levesque et al, 2017) and educational recommendations aligning with these functions (e.g., National Governors Association Center for Best Practices, Council of Chief State School Officers, 2010). Here we report on a longitudinal study testing morphological decoding and analysis as two mechanisms by which morphological awareness supports the development of reading comprehension.…”