[Sigia-l] Use cases and user centric design (was sitepath diagramming)

[Katherine Marshak]

(Sorry for the delayed response -- project work prevailed.)

Laura,
Actors & personas are related because actors help define requirements
and personas define targets for design. There is not necessarily a 1:1
relationship between actors & personas. Often, actors do not have
related personas because (1) they represent systems or (2) they are not
the primary users so they don't warrant the effort. A single actor may
also have multiple personas associated to it.

Your online grocery example is an excellent case. In fact, I often use
it. You could have Maria Hornbooth, a persona representing the weekly
methodical shopper, and Oscar Novaco, a persona representing the
occasional shopper. Both personas could be related to a single actor
named Online Grocery Shopper. 

This very fact helps make actors more concrete. It provides a way to
overcome the fact that some people look at the Online Grocery Shopper
actor & think of the methodical weekly shopper while others think of the
rare user. When using personas & actors together, you can ask the
question, "Are you thinking about Maria-the-methodical or
Oscar-the-occasional?" 

You also asked how we get over this "conflict" in our work...
In our requirements courses, we teach people about actors before we
teach them about personas. 

With our own project teams or while mentoring clients, we figure out
which concept someone already knows & then explain the other to them.  

One issue that has come up repeatedly is whether the scenarios described
in the personas are 'requirements.' I say no. The personas are a way to
share the results of user research and make the users we're focusing on
during design come to life. The use case specifications are the
requirements. The persona scenarios can help us define requirement and
assess the usability of the requirements and its design. The scenarios
may get modified as requirements are being defined & priorities are set.
The persona scenarios may actually be spread across multiple use cases,
too.  

If you see other issues with this approach, please let me know. I'm
writing a white paper on this topic & am interested in others'
perspectives. 

And yes, I agree that Constantine & Lockwood's work is useful. 

Thanks! 

Kathy Marshak, Senior Consultant 
IconMedialab | www.iconmedialab.com 
IconProcess | www.iconprocess.com  
Training | www.training.iconmedialab.com 
voice: + 1 636 530 7776