Learning Usability from mini-van

One of the important aspects of "software usability" is to minimize the number of user actions such as mouse-click and enterying a key.

It is obvous that fewer is better, but when and for what feature is it appropriate to make it fewer clicks? Well, you have to figure it out by seeing what users do: what is the goal user is trying to accomplish? Does certain gesture tells us about the user goal?

I have a mini-van for my family and learned one essence of how to think about user goals. I have a key (obviously) and when I insert the key to door at the "driver's side", if I turn the key once, it opens the driver's door, and if I turn once more, then it opens "all" doors. So, it takes twice to open all doors.

In contrast, if you insert the key at the passenger's side door and turn once, "all" doors open. Appearently, the similar "door opening" mechanism is configured (programmed?) differently.... why? It's is because the chances are the if someone is opening the passenger's side door, it is likely that a family members are getting to the van. However, if someone opens the "driver's door", it is somewhat more likely that it is just you, driver, who wants to get in.

These are similar to the number of mouse clicks. If you study the "situations" underwhich your software is used, and if certain gestures strongly indicate certain user goals, then system should be programmed to achieve the goal in the least amount of user actions.