Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)


Computer Information Systems

First Advisor

Detmar Straub - Chair

Second Advisor

Michael Gallivan

Third Advisor

Geoffrey Hubona

Fourth Advisor

Arun Rai

Fifth Advisor

Daniel Robey


Information systems are designed to support human and organizational purposes. To achieve their ends, information systems must be used. Although this may seem to be self-evident, there are many aspects of systems usage that are not so, and yet, in spite of this, there has been little intense conceptual scrutiny of this construct in past research. The objective of this thesis, therefore, is to develop new in-depth perspectives for studying system usage. Drawing on critical realist assumptions and studies of research diversity, I explain how epistemological factors enable while ontological factors constrain the diversity of meanings of system usage, and I build on this reasoning to advance a systematic approach for conceptualizing and measuring system usage in an appropriate way for a given research context. To demonstrate the approach and judge its usefulness, I carry out three empirical studies to test whether measures of system usage that are selected according to the proposed approach provide more explanatory power and lead to more coherent results in specific research contexts than other measures of system usage. Exploring the relationship between system usage and user task performance among 804 users of spreadsheet software, the experiments reveal support for the usefulness of the approach and demonstrate how it can enable researchers to conceptualize and measure system usage in an appropriate manner for a given research context. Together, the conceptual approach and empirical studies contribute by: (1) providing a systematic way to conceptualize and measure system usage for a given study context, (2) revealing rich new directions for research on the nature of system usage, its antecedents, and its consequences, and (3) suggesting a new approach for construct development and investigation in IS research.