HOW TO USE IT

The main display describes how to operate the model.

1) Select the number of Shepherds and Sheep you wish to have (or, leave the numbers the way they are)

2) Select a backdrop to use - Open field (no barriers) - Riverside (a fenced pasture with a river and a bridge) - Corral (a corral with an open gate) - Island (a series of nearly isolated land masses)

3) Click on the Go button to start the model

4) Adjust the following variables at anytime (try the defaults first):

Change the speed of the sheep (how fast they wander),

Slow down the model so you can more easily observe specific behaviors

Track an individual shepherd (he'll light up red)

THINGS TO NOTICE

The Shepherds are the brown agents running about.

When a Shepherd finds a wandering sheep and picks it up, he turns light brown.

The Shepherd will always try to place the sheep he is carrying next to another nearby sheep. THERE IS NO PLAN to herd the sheep in any particular place. The shepherds operate in a completely decentralized, agent-rules based system.

Sometimes the "herding" effect is seen quickly, other times you have to wait a little longer. And, the ease with which herding is accomplished is based on the settings of the variables. For instance, try setting the sheep speed to zero (0) and watch how quickly the sheep begin to be gathered into small herds and eventually one large herd. Speed the sheep up and see what happens.

Try playing with the variables: quantity of sheep vs. shepherds, the speed of the sheep, and the different backdrops.

How do the results vary when the variables are given different settings?

In the corral scenario, will a single herd form inside or outside the corral?

In the riverside scenario, will a single herd form on either side of the river?

Is there a particular island on which the herds form more frequently?

EXPLORATIONS

If you're the curious or playful type, you may wish to create your own custom scenario. You can do so by using the paint tools to paint your own design onto the patches. To save your creation, open the graphics window to its fullest. You will see some buttons down below that were previously hidden from view. Click on one of the blue "Save.." buttons. Then use File-Save As to save the model under a new name. Now you can run this model and select your custom backdrop as the playfield. TIP: when drawing surfaces that the sheep can walk around on, use only the colors that are used in the existing scenarios -- certain greens and browns. All other colors the sheep will treat like barriers.

CREDITS AND REFERENCES

As noted above, "Shepherds" is inspired by the "Termites" model. "Shepherds" was created by Greg Malone (gregmalone@gregmalone.com).