What you already know
A persona is a character who represents a certain segment of the people you potentially support. The segment could be a marketing segment, focused on how people buy your services. The segment could be a behavioral segment, drawn from hours of generative interviews and analysis. Or it could be a segment from another way of looking at people which is important to your organization–perhaps hair type, if you are a hair salon. There are lots of ways to segment people.
What you are wondering about
You also know there are different scopes that your organization attempts to cover. If you build, sell, and maintain data management products and consulting services, your scopes might include “get the word out to people who don’t know about us,” “help developers resolve tricky situations using our code,” “teach new developers how to use our code,” “support our own engineers keeping up to date with techniques,” “convince customers to upgrade to our latest version,” etc. You realize, with slight doubt, that there could be several personas for each of these scopes. Let’s count just the ideas I’ve mentioned: five scopes, and say there are three or four personas per scope. Does that mean there can be 15 to 20 different personas?? This possibility is daunting. Its seems like it’s too much to wield adroitly to imagine scenarios and invent customized tools as support.
How to get your head around it
Each scope, if they are defined narrowly enough, usually results in three or four behavioral segments. Each scope also usually results in one mental model, but sometimes there is one behavioral segment that is different enough that I split the data into two mental models, one representing that segment. Once, the data got split into three mental models, but I think that was more because we had defined too broad a scope to begin with, and narrowed it into three scopes when we divided the data. These three mental models all shared the same three behavioral segments, to different degrees. This is the point I want to make. Just because each scope has its own set of personas doesn’t mean that some of those characters can’t be the same across scopes.
There, now that I’ve said that, it all makes sense. You can have one master list of characters, just like in a television show. Some of those characters appear in every episode of the show. Some only appear in one episode. If you imagine each episode as a scope in your research, you have a perfect analogy.
But wait a minute. I just switched from saying “behavioral segment” to saying “persona” or “character.” You caught that. True. They are not one-to-one, necessarily. You might want to make a couple of personas to represent different demographic or purchasing aspects of the behavioral segment. You might have a behavioral segment that is unhappy about taking business trips. One character representing this segment might be a mother who is focused on spending as much time as she can with her toddlers while they are pre-schoolers. Usually travels in the cheapest seat her company can buy. Another character of this same behavioral group might be a businesswoman who has spent so many years traveling every other week that she is tired of hotels and just wants to be home in her own bed more often. She usually travels in business class and enjoys boarding priority. A third character in this group could be a younger woman with a fear of flying. Perhaps she only buys one ticket a year. Each persona you create is a character, like in a television show. Each persona has a first name. A few of the personas could represent the same behavioral segment, just like a few of the characters in a show might represent the same motivations. I can think of one example: the companions of Doctor Who, over the years, all represent the motivation to pursue excitement, see amazing things, and be near a person whom they love and revere. That is one behavioral segment with several different characters in it.
As you collect more research over the years and explore more scopes, you will add to your cast of characters. Sometimes you will discover the same behavioral segment in a new scope and decide to keep the character(s) you already defined for it. Sometimes you will decide it will illuminate a business problem better to invent a new character within that same behavioral segment. Keep track of these characters over time, the business problem they clarify, the behavioral segment they belong to, and the scopes they are active in.