There are very few software packages for model-building and visualization in electromagnetic geophysics, particularly when compared to other geophysical disciplines, such as seismology. The purpose of this thesis is to design, develop, and test a geophysical model-building interface that allows users to parameterize the 2D magnetotellurics problem. Through the evaluation of this interface, feedback was collected from a usability specialist and a group of geophysics graduate students to study the steps users take to work through the 2D forward-modeling problem, and to analyze usability errors encountered while working with the interface to gain a better understanding of how to build a more effective interface. Similar work has been conducted on interface design in other fields, such as medicine and consumer websites.

Usability Engineering is the application of a systematic set of methods to the design and development of software with the goal of making the software more learnable, easy to use, and accessible. Two different Usability Engineering techniques — Heuristic Evaluation and Thinking Aloud Protocol — were involved in the evaluation of the interface designed in this study (FEM2DGUI). Heuristic Evaluation is a usability inspection method that employs a usability specialist to detect errors based on a known set of guidelines and personal experience. Thinking Aloud Protocol is a usability evaluation method where potential end-users are observed as they verbalize their every step as they work through specific scenarios with an interface. These Usability Engineering methods were combined in a effort to understand how the first prototype of FEM2DGUI could be refined to make it more usable and to understand how end-users work through the forward-modeling problem.

The Usability Engineering methods employed in this project uncovered multiple usability errors that were corrected through a refinement of the interface. Discovery of these errors helped with refining the system to become more robust and usable, which is believed to aid users in more efficient model-building. Because geophysical model-building is inherently a difficult task, it is possible that other model-building graphical user interfaces could benefit from the application of Usability Engineering methods, such as those presented in this research.â