As I was writing another question here at UX, I realized that I wanted to discuss more things pertaining to the same problem. I thought it would be a good idea to split the question into two since they are somewhat different by nature.
When writing user interfaces that are aimed at being used by a lot of different users with a wide range of experience levels, many of whom do not use a computer on a daily basis, is it better to strictly stick to the conventions or is it a good idea to try to guide the user with experience altering solutions of varying sophistication levels?
Take the simple task of switching focus from one input field to another in a web based form for example:
An experienced user would most likely use the tab-key to switch back and forth between the fields, while a less experienced user might use the mouse to navigate the form. In this case, would it be better to stick with the convention of simply putting the cursor in the field without selecting anything when using the mouse and selecting all text when using the tab-key. Or would it be a good idea to use some kind of technique to work around the conventional behavior and having all text selected when using the mouse too?