Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)

Graduate Group


First Advisor

Yuko G. Butler


This study investigates the effects of four online vocabulary tasks on second language (L2) vocabulary acquisition among learners of different proficiency levels. While tasks are widely used to support L2 vocabulary learning, the efficacy of a task depends on the interplay between task and learner factors. Thus, choosing an appropriate task requires not only identifying the task features which may foster cognitive processes that contribute to learning, but also considering how the effects of such features may be moderated by factors outside of the task. The present study aims to provide insights into this issue by exploring the effects of various task features on L2 vocabulary acquisition and the potential moderating role of one learner factor, L2 proficiency. Drawing from the involvement load hypothesis (ILH) and technique feature analysis (TFA), four instructional tasks which varied in their inclusion of features believed to facilitate vocabulary learning were selected for the study: (a) sentence writing (SW), (b) fill-in-the-blank (FIB), (c) fill-in-the-blank with pictures and audio (FIB+PA), and (d) word study with pictures and audio plus fill-in-the-blank (WS+PA+FIB). A total of 75 participants with high intermediate or advanced proficiency in English were randomly assigned to complete one of the four instructional tasks or a control task online. Participants’ vocabulary knowledge was measured through a modified version of the Vocabulary Knowledge Scale (VKS) and a multiple-choice recognition test from which meaning recall, meaning recognition, and total VKS scores were obtained. Findings from multiple regression analyses and ANOVAs indicated that in general, the instructional tasks led to greater learning gains than the control task. Furthermore, among the instructional tasks, SW and WS+PA+FIB tended to be more effective than FIB and FIB+PA in promoting vocabulary learning. However, there was also evidence that the effects of the tasks were moderated by L2 proficiency, as SW and FIB effects were found to be more salient for advanced learners. These results are interpreted from the perspective of different cognitive processing theories, and the implications for L2 vocabulary acquisition theory and pedagogy are discussed.