Chapter 5: Modeling Users: Personas and Goals

Part I: Understanding Goal-Directed Design
description, along with a short,fietional paragraph describing the kind ofcar this
person drives, how many kids he has, where he liv&", and what he does for a living.
This kind of user profiJe is likely to be based on a stereotype and is not useful as a
design tool. Although we give our personas names, and sometimes even cars and
family members, these are employed sparingly as narrative tools to help better
communicate the real underlying data. Supporting fictional detail plays only the
most minor part in persona creation and is used just enough to make the persona
come to life in the minds of the designers and the product team.
Personas versus market segments
Marketing professionals may be familiar with a process similar to persona development
because it shares some process similarities with market definition. The main
difference between market segments and design personas is that the former are
based on demographics, distribution channels, and purchasing behavior, whereas
the latter are based on usage behavior and motivations. The two are not the same
and don't serve the same purpose. Marketing personas shed light on the sales
process, whereas design personas shed light on the product definition and development
process.
However, market segments playa role in persona development. They can help deter·
mine the demographic range within which to frame the persona hypothesis (see
Chapter 4). Personas are segmented along ranges ofusage behavior, not demographics
or buying behavior, so there is seldom a one·to-one mapping ofmarket segments
to personas. Rather, market segments can act as an initial filter to limit the scope of
interviews to people within target markets (see Figure 5-3). Also, we typically use the
prioritization ofpersonas as a way to make strategic product definition decisions (see
the discussion of persona types later in this chapter). These decisions should incorporate
market intelligence; an understanding of the relationship between user personas
and market segments can be an important consideration here.
When rigorous personas aren't possible:
Provisional personas
Although it is highly desirable that personas be based upon detailed qualitath~
data, there are some occasions when there simply is not enough time, resources, or
corporate buy-in to perform the necessary fieldwork. In these cases, provisionllo
personas (or, as Don Norman refers to them, "ad hoc" personas) can be useful
rhetorical tools to clearly communicate assumptions about who the importanf
users are and what they need, and to enforce rigorous thinking about serving spe"
cific user needs (even if these needs are not validated).
Market J'
'I
Figure 5.3
the Researc
there is sek
ProVisional
data and de
typically bas
edge ofusen
108 market,
hypothesis (c
Our experien
yields better I
~nas can hel
tures and bel:
this because tl
qualitative dOlt
Det learn, ifyo
.. Focus
.. FOCus,
produc