We generally encourage people to think of the personal assistant in human-like terms. If you can speak to a person and ask for what you want you should be able to use the system without much difficulty. Depending on where you are in the system you will only be able to ask for certain tasks - it is different to talking with a person and takes a little practice.
The assistant is very friendly and she will walk you through each task step-by-step. If you get stuck you just ask for help and she will tell you what you can do. If you get really stuck there is a community of people willing to offer assistance.
After using the system for a few minutes most people can find their way around comfortably, even if they've never used a computer before.