For a more general system like GNOME, it's a universe of possible users! GNOME does not target a particular class of users, such as developers or computer experts. Rather, GNOME targets all users. That's why I didn't define personas in my usability test; it was everyone.
However, it is very helpful to define personas for a project. Ultimately, personas are a project decision. The project needs to agree to the personas that sufficiently represent their users. Personas allow everyone in the project to discuss concrete examples how design patterns and decisions will affect users. With personas that everyone agrees to, discussion is focused on users: "How does this help 'Emily'?" or "How would 'Roger' use this?" Without personas, discussion tends to become unfocused, leading to scope creep, such as "How can I do —?" or "What about someone who wants to do —?"
So it's important to define personas. But how to define them for a general system like GNOME?
I find it's helpful to break down the possible personas into categories and work from there. In this case, let's start with "GNOME is for users of all ages, of all experience levels." So that gives you a 2-dimensional problem: experience v age.
From there, you might choose to divide the age group into thirds (for example, by "generation": Millennial ages 11-31, GenX ages 31-51, Boomers ages 51-69) and experience into thirds (for example: Beginner, Moderate, Experienced). This means you need to define 9 personas:
Or, you could divide the experience into four areas (for example: Beginner, Moderate, Experienced, Expert). This means you need to define 12 personas:
How to do this breakdown is up to the consultant and the project team. For example, you could instead break up the ages into more than 3 categories to better represent certain age groups (elementary-age students, junior high & high school students, college students, post-college ages 22-31, etc.) Ultimately, the project needs to decide what breakdown is sufficient.
In a work project, the consultant must understand the preferences and target audience of the project group, but also perform independent research to be sure the possible users are represented correctly. Then the consultant suggests a breakdown, which the project team would review and discuss. Once the project agreed to the breakdown, and any "edge" cases (visually impaired users, etc) the consultant creates personas for each, for the project to review and finally agree to.
For simplicity, and for sake of giving an example, let's assume the project team agreed to the 3x3 model. In that case, the consultant creates personas that represent the 9 classes of users:
- someone between ages 11-31 who is a Beginner user
- someone between ages 11-31 who is a Moderate user
- someone between ages 11-31 who is an Expert user
- someone between ages 31-51 who is a Beginner user
- someone between ages 31-51 who is a Moderate user
- someone between ages 31-51 who is an Expert user
- someone between ages 51-69 who is a Beginner user
- someone between ages 51-69 who is a Moderate user
- someone between ages 51-69 who is an Expert user
Don't forget to be inclusive and representative of gender: male, female, and trans. For example, you might define 4 male personas, 4 female personas, and 1 trans persona.
As you define these personas, you shouldn't shoot for the middle of each box. For example, you don't have to pick the center of each age group. Use some randomness:
However, for this usability project, we're going to focus on persona representing a Moderate user with some "average" age.
image: Outreach Program for Women