In one study we conducted with Motorola cell phone users, for example, we found there were twenty-one different ways in which customers defined "easy to use." Their desired outcomes included, "minimizing the time it takes to look up a needed phone number," "minimizing the likelihood of calls being made by inadvertently hitting the keypad," and "minimizing the time it takes to dial a number without looking at the keypad." In each of those situations, "easy to use" takes on a different meaning and has different implications for designers seeking to improve or extend the product.
