Re: Design + Usability, Useful + Usable

At 02:00 AM 12/12/2007 -0800, Mimi Yin wrote:
>I see our biggest
>challenge as articulating what that mindset is to users in a way they
>can understand at a gut-level. I have a feeling that it's not in any
>of the ways we've tried to articulate it thus far.

Right - the trick is that a "mindset" isn't something that exists 
operationally in brains, any more than a program's requirements 
definition is written in a program's source code.

In order to use a program -- or any tool, including one's own body 
parts -- the brain needs to construct a goal-action or 
"forward/backward prediction" model.  That is, "If I want this, these 
are the actions to take" (backward model) and "If I do this, this 
will happen."  (forward model)

People learn everything from how to twitch their left big toe, to how 
to be a professional photographer using this identical 
mechanism.  This is how "gut-level" understanding literally operates.

Unfortunately, these understandings cannot be directly constructed 
verbally; they have to be unpacked into a series of experiences in 
order to be communicated -- *unless the user already has the relevant 
experiences*, in which case an understanding can be *assembled* verbally.

A few ways to convery the relevant experiences or assemble them:

* Encoding explicit goal information into the program ("opinionated" 
- works by making goals explicit and letting behavior be discovered)

* Make the behavior of the program simple enough to be trivially 
predicted by the user, without them having to think about it ("tool" 
- leverages experience of similar systems and relies on user for 
assembling to goals)

* Create a series of structured experiences so the user incrementally 
discovers behavior and updates their mental model.  This can be done 
via books, tutorials, one-on-one training, etc, but the experiences 
have to be sequenced and structured if the model isn't clearly 
discoverable by either naive or highly-experienced users.

In other words, if you don't want to either simplify the behavior or 
make the goal-action links explicit, the only thing left is teaching.

I think it's important to reiterate: conveying only a usage 
"philosophy" or "mindset" *cannot* give anyone the ability to use the 
software.  They *must* build a 2-way predictive model in their mind, 
even if the way you give it to them is by doing things with the 
program and talking about it, or showing pictures and instructions in 
a book, etc.

By the way, to be clear, when I call something "simple", I mean 
"predictable using fewer mental variables".  The more state-dependent 
the system behavior, the harder it is to construct a forward/backward 
model in your head -- or more precisely, in your gut.

For example, Chandler's overlay mechanism and the non-orthogonal 
interplay between filter/view selection and the overlay mechanism is 
incredibly frustrating to me as a user, because I don't know what the 
heck anything is going to do.  If I stop and think about it, I can -- 
usually -- figure it out, but if I just try to *use* it, it 
constantly surprises me.  So my attempts at getting into flow are frustrated.

The thing is, you *have* to have, as you say, a "gut-level" 
understanding.  Problem is, guts usually have to learn complex things 
from simple (and ideally independent) pieces.  But Chandler is not 
"simple" in this sense.

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Open Source Applications Foundation "Design" mailing list
http://lists.osafoundation.org/mailman/listinfo/design