Chapter Four. Usability Design and Evaluation for Privacy and Security Solutions

Clare-Marie Karat, Carolyn Brodie, and John Karat

THIS CHAPTER SHOWS HOW YOU CAN INCORPORATE USABILITY DESIGN AND EVALUATION into the life cycle of privacy and security solutions. Here we provide you with an overview of critical-path human-computer interaction (HCI) activities that occur during the development of successful solutions and their maintenance after release. We will point you to key publications and references that you can use to gain a more in-depth understanding of HCI methods and practices in evaluating the usability of your security and privacy systems. And we will walk you through the use of these methods in a case study of a security application as well as a case study of two years of research on privacy tools for authoring and implementing privacy policies.

Of course, this chapter alone cannot make you proficient in using HCI methods. But it will guide you in understanding the value that HCI work can contribute to the success of your product.

We recommend that most projects bring an HCI expert on board early in the project's development, and that the HCI expert be a full team member. Working together, the project team should define the usability activities as a critical development path. We have seen many successful examples where the HCI lead's expertise was leveraged to train and educate the product team so that team members completed parts of the HCI project plan with consultation and collaboration from the HCI expert. We have also seen several examples of skilled computer scientists and programmers who gradually became HCI specialists, frequently with great success. One of this chapter's co-authors, Carolyn, has, in fact, followed such a career path!