“…The resulting hierarchical, developmental progression described by stage theorists evolved from the identification of similar error patterns in learners. These error patterns were based on spelling data across thousands of learners at different grade levels and within different instructional contexts (e.g., Beers, 1980; Gehsmann, Spichtig, & Tousley, 2017; Invernizzi & DeCoster, 2016; Snowling, 1994). This progression was described in terms of stages during which learners are observed to move from emergent literacy behaviors through understanding the function of alphabet, sound, pattern, and morphology in the spelling system.…”