The next step is for you to try out
Net Logo and to do an exercise and a quiz.

The exercises and the quizzes in this 
course are optional and don't count

for your grade, but I highly recommend 
doing them to helping your learning

the course material and also to test your
understanding of what we've done so far.

This exercise is going to use a slightly
modified version of the ants model

from the models library, the modified
version is called "AntsNew.nlogo".

You can download this modified version
by clicking on the "AntsNew.nlogo" link

below the video window, or by going to
the course materials page.

So let me show you how to do that: here
I am on the page with the video window,

under this video, you should see 
"AntsNew.nlogo".

I click on it, it asks me if I want to
save it, so I do,

it's a binary file, [click] "save".
And here we...it shows up on my desktop

because I saved it to my desktop,
and I double-click on it to open it up.

And it should open up with ants"AntsNew",
the new ants model, loaded into NetLogo.

Let's go back to look at the exercise.

It asks us to set the population to 200
and the diffusion rate to 20,

and then test three different evaporation
rates to see which one makes the ants

eat all the food the fastest.

Well, each one of these is going to have
a variety of times it takes for the ants

to eat all of the food, because there is
randomness in the program.

What you are going to do is run the model
5 times for each of these values,

and for each run, record the number of 
ticks it takes

until all the food is eaten.

Now, remember to
click "Set up" before each run.

At the end, you average those five numbers

for each of these settings of 
evaporation rate,

and then see which average time is
the fastest.

So let's try that.

The population is 200, we set the 
diffusion rate to 20 by sliding it,

and let's start with evaporation rate
with zero, so I do "Set up" and then "Go"

And again I can increase the speed
by sliding this speed bar.

And now I see that it took on this run,
613 ticks for the ants

to eat all of the food.

I do it again,

"Go".

And that time it took 758 ticks for the 
ants to eat all the food.

So you would do that 5 times,
average those 5 numbers,

and then you would set 
the evaporation rate to 5

for the next set of experiments
and then to 20.

And remember to do
"Set up" each time you start a run.

And after you do this exercise, there 
will be a quiz to ask you to think about

why you see the behaviour that you see.