Personas. Utility Vs. Representativity
Saturday, 20 de June de 2009
The design technique of persona is useful in the design of successful products. This tool lets you align the needs and expectations of the product of all those involved in development. They are involved both the coreteam of product, also stakeholders and hippos. In addition to using characters prevents deviations of the goals of product design.
Because, the persona´s technical should be mandatory in all development.
Although, sometimes you can find difficulties to personas be accepted.
The difficulties may come from the nature of the persona because they are abstractions, although based on real data, but do not represent an real users with name and a surname, but the persona have it. (For more information about the technique see Persona y scenarios. A methodology introduction (SP))
This feature makes that sometimes arise opinions about the appropriateness of the use of persona, and there are doubts about its pragmatism over the use of real users, which may seem more logical in principle, but as we shall see below that it is less efficient .
The personas are part of the tactic of development, while potential customers are a strategic element of the product.
The main idea is that the persona do not represent a particular user as such, but are composed of many of the personas of potential users. To these characteristics we call “variables”.
The personas are abstractions, but are based on data.
Do not you have to invent, there is a preliminary analysis and investigation. Otherwise you will not do.
We should not confuse “everybody can use it” in terms of usability with “everybody want use it” in marketing terms. Sometimes the discussions about the appropriateness of the use of personas is thinking about how to influence marketing. And that is also wrong.
There may be a relationship between personas and real users, but is not a direct relationship between personas and users or customers, but the personas are related by the users through the product variables.
A persona is composed of variables, a more variable´s personas it reasonable to assume that there will be a smaller number of real users that fit the character. This is one of the reasons why the characters are used. Greatly simplify the process by allowing us to work with multiple variables at once. It also keeps the user selection and recruitment, which can be extremely complex for some variables.
This relationship is representative of one of the factors that you can not establish a direct relationship. Since more detailed level of the least number of personas that fit real people in them.
This also explains why the convenience of designing the product for the principal persona.
Could almost say that when a persona is well developed, should not allow us to identify a specific individual, but should remind us of many traits.
Therefore one might think that knowing the variables, we could save the job of developing personas. But on the design variables in a ungroup the persona were difficult to establish use cases, which diminishes the efficiency process. The human we are better able to establish empathic relationships when we reach the place of another “person” (though it is imaginary) that when we do it directly from the variables.
Let’s see this implemented in a classic example of characters taken from the Paper,Personas, Participatory Design and Product Development:An Infrastructure for Engagement of Grudin and Pruitt.
This paper defines a persona with a high degree of detail. For example “Patrick” is defined in 21 different variables, if the possibility of a potential user has an attribute that is either is 50%, about 21 variables as a result gives us a 0.000047% of real people who fit as Patrick has defined, which for a population like the U.S. at 2009 is 146 real people.
This is calculated as follows:
(0.5) ^21 *100%= 0.000047%
(306,711,000*0.000047)/100= 146
Now, if we define to allow team Patrick and establish a relationship with him that the product is designed with “Patrick in the mind” design decisions will be more constant and consistent throughout the process, that if link to a list of variables that can be interpreted differently by different teams of agents.
It also seems easier and cheaper to find people that use “user type” meeting with the desired characteristics, and implications in the design process.
Conclusion
• The personas are a design tool that allows the goals of the product remain constant, making products more consistent. This is the purpose of the technique, and you should not forgotten .
• You can not expect to link users with the personas in a linear fashion, why not have the same kind, the comparisons should be set on variables where necessary. Here is where I believe that this error of Chapman and Milham, who in his paper “The Personas´ New Clothes:Methodological and Practical Arguments against a Popular Method” with an argument based on the calculations outlined above indicate that the technique is wrong because personas can not connect with real users.
• And if you replace the potential users (customers) by characters is a mistake, that the target will see significantly reduced to dangerous levels and lack of business sense.
• Recently the technique has been tested on the personas design of a product that reduces discovering the shortcomings identified through usability heuristic analysis between 2 and 4 times less when using the technique of characters.
References:
The MUSiC methods were specifically developed by the European MUSiC (
