Exploration Through Example

Example-driven development, Agile testing, context-driven testing, Agile programming, Ruby, and other things of interest to Brian Marick
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Sun, 07 Mar 2004

Sensors; and what to sense

Yesterday I sat in on a few sessions of the W. Ross Ashby Centenary Conference. Two papers presented might tie into some of my recent themes.

Peter Cariani spoke on Epistemology and Mechanism: Ashby's Theory of Adaptive Systems. I was taken by this picture:

This is an elaboration of an ordinary feedback loop. Following the outside arrows from the bottom, we see there's an environment. Sensors detect things about the environment, then a controller makes decisions based on them. Those decisions lead to actions, which affect the environment. The elaboration is that the organism can change the set of sensors that it uses if tests reveal that it's not doing well enough. Cariani says of such organism that it is "capable of learning new perceptual categories". That ties into my recent writeup of tacit knowledge, in which I said of a veterinary student who's learned an important diagnostic category:

"Cows simply are either bright or dull, the way the student herself is either alert or sleepy, or the way a joke is either funny or lame. Any explanation of how she knows seems contrived and after the fact. It's as if the student's perceptual world has expanded."

Hold that thought - malleability of perception - for a moment.

Peter Asaro spoke on Ashby's Embodied Representations: Towards a Theory of Perception and Mind. I was struck by something he said about bees. Suppose you're a bee navigating down a tunnel. You don't want to crash into either side. How can you do it? Well, consider what happens as you drift toward the right side. Features on the right wall will appear to go by you faster, features on the left slower. So just have that specific perception trigger changes in your wing flapping that shift you to the left. You don't need a "world model" with any accuracy; rather, to be a successful bee, you need a diverse set of perceptions that are well tuned to the tasks you need, as a bee, to perform.

Since I'm Mr. Analogy Guy, I of course thought of software projects as needing to be more like bees, especially projects that seem to me to be stuck. The problem is not so much that they don't know what to do. Rather, it's that they don't perceive their problem in a way that allows them to quickly turn it into some action that brings their environment more in alignment with their goals.

So I've recently been trying to think of Big Visible Charts and project dashboards that practically impel action. So, rather than talk about how there are too many meetings, instead put up a chart like this in a public place:

Each bar represents a day, measured in burdened dollars. The red portion is that amount of that day's project expense devoted to meetings. What I hope will happen is illustrated by Friday's bar, in which people's visceral reaction to red provokes the action of fewer meetings.

Putting up such a chart is a little gutsy, of course, but what're they going to do, fire you? In this economy? Oh wait, it's not 1997...

P.S. for the gadget enthusiast: Cariani showed a picture of a device that could grow its own sensors, constructed in the late '50s. There's something very cool about it. (Scroll down for bigger pictures.)

## Posted at 16:48 in category /agile [permalink] [top]

About Brian Marick
I consult mainly on Agile software development, with a special focus on how testing fits in.

Contact me here: marick@exampler.com.




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Working your way out of the automated GUI testing tarpit
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