Eaton Electrical Corp. came to MAYA with a high-voltage electric-power meter and some interesting challenges: How could they add features without adding more buttons? Could a single knob be the primary control? Could the interface work on multiple devices in this product family, even with widely varying displays?
Personas
We have to get “inside the heads of users” before we can begin designing. So we created personas — descriptions of key types of users and their most important needs. What mental models about meters do users have? How do they understand the structure of the information space? We identified five representative user types for the power meter and fleshed out their characteristics in a way that, if our meter design satisfied them, it would satisfy the most important, targeted users.
Information Architecture
MAYA defined a “Bubble-Up/Drill-Down” information architecture that took into account more than 300 possible measurements, organizing them by relative importance to users. Information is progressively disclosed as users move from summaries to details.
User Studies
Based on the IA, we designed a functional prototype for rigorous usability tests to identify potential problems before significant development and investment. To match the users’ mental model, our design combined the best of analog and digital displays. User tests proved that it was possible to operate a complex system using a Web browser and a single controller.
User Interface
MAYA worked with Eaton to design an intuitive meter controllable with a single knob, plus a “back” button. Further, we devised a “recipe” that formulaically translates UI designs among several different types of displays, for example, a 1/4-VGA screen will also work on a meter with a 4/20-character display or even a Web browser. The well-defined IA allows Eaton to expand the information space of the meter without breaking the continuity of the design or starting from scratch.
Results
Our design jumps Eaton to the head of the line in their market with a product that, despite its power and complexity, is easy to use, requires little training, and has an exceptionally low barrier to entry. Representatives from Eaton beamed when veteran users tried the next-generation meter and said, “Now that’s a meter!”