Morphological Complexity in Writing: Implications for Writing Quality and Patterns of Change

Area of Science:

• Linguistics
• Education
• Developmental Psychology

Background:

• Morphologically complex words (MCWs) are crucial for advanced writing.
• Understanding MCW development in diverse student populations is essential for effective literacy instruction.

Purpose of the Study:

• To examine the relationship between morphologically complex word (MCW) use and writing quality.
• To assess the change in MCW use throughout the academic year.
• To investigate differential MCW growth among students with varying language abilities, including developmental language disorders (DLD) and multilingual learners (MLs).

Main Methods:

• Collected expository writing samples from 824 fifth-grade students (including 109 with DLD and 170 MLs).
• Coded written responses for MCW usage.
• Utilized correlational analyses and hierarchical linear models to analyze MCW use, writing quality, and growth over time, accounting for classroom structures.

Main Results:

• A moderate correlation (r = .47) was found between MCW use and teachers' writing quality ratings.
• Significant increases in MCW use were observed across all students from fall to spring.
• MLs and students with DLD exhibited significantly lower growth in MCW use compared to their peers.

Conclusions:

• MCW use is a valuable indicator for assessing written language development and progress.
• Differential growth patterns suggest potential 'Matthew effects' for MLs and students with DLD.
• Further research into instructional strategies supporting complex vocabulary acquisition is warranted for these student groups.