Students can learn to spell words by implicit or explicit learning. This study investigated how effects of implicit and explicit learning experiences were moderated by students' spelling ability and general academic achievement as measured by the Woodcock Johnson III Spelling test and ACT tests. Undergraduate students participated in either an implicit or an explicit learning experience. Students in the implicit learning session read 30 passages with embedded target words, whereas students in the explicit learning session studied the spellings of 30 words on a list with accompanying sentences. All students completed a spelling dictation test, a questionnaire, and a recognition test. The dictation test consisted of 30 words that students encountered in the learning experience, 30 control words, and 25 words from the Woodcock Johnson III Spelling test. Dictation scores served as indicators of implicit and explicit learning.

Students' general achievement as measured by composite ACT scores explained a substantial portion of the variance in their dictation scores. This was observed for spelling words that were exposed in both the implicit and explicit conditions as well as for unexposed words. Students' Woodcock-Johnson III Spelling scores moderated the effects of the learning experience. Although good spellers learned in both explicit and implicit conditions, they performed best when they learned to spell words explicitly. Poor spellers exhibited minimal learning in both explicit and implicit conditions.

These results are discussed in light of Berninger's triple word form awareness and mapping theory (Berninger, Abbott, Thomson, Wagner, Swanson, Wijsman, & Raskind, 2006) and Perfetti's lexical quality hypothesis (Perfetti & Hart, 2002). Finally, the study's limitations are noted and instructional implications are presented.