[MWForum]When or if

[Trish Sims]

HelloAll

I've been teaching year 8's (age 14) to use MicroWorlds. Lots of very
successful projects but I'm having difficulty understanding and explaining
the difference between proceedures that include

when [touching? "t1 "t2] etc

and

if [touching? "t1 "t2] etc

These procedures are used to especially in races to program colour or to
determine when/if turtles touch. Any suggestions would be greatly
appreciated.

Trish Sims
Strathmore Secondary College