There’s a great article at User Interface Engineering about how to construct personas.
Simply put, you should:
- Keep the personas to a small set
- Describe the needs of the personas, not the personas themselves
- Keep the personas abstracted by not including too much personal detail about each of them
- Keep the personas specific to the design problem
If you bear in mind the needs of the personas (a needs-driven approach), you shouldn’t have too many problems. List all the disparate needs of your users, and then group them into distinct personas. You can them give them names and a bit of character if necessary.
This should result in a high-quality set of personas to drive the user stories from, and should prevent ‘grounding’ – which is what happens when the developers start injecting their personal opinion into the features.