Holding down Ctrl and rolling the mouse wheel is a widely accepted mechanism for zooming. There are two obvious, intuitive mental models that you can use:
- By rolling the wheel you are moving yourself. So roll the wheel towards the screen to make the screen look closer (bigger), roll away from the screen to make it look further away (smaller).
- By rolling the wheel you are moving the screen. So roll the wheel away from you to make the screen look further away (smaller), roll towards you to make the screen look closer (bigger).
As Windows software manufacturers we can’t pass judgement on these alternatives: it is our duty to adopt whichever convention is being used by all the other Windows software out there. When there is disagreement, we have to judge which manufacturer is likely to beat the others, and thus which convention is likely to dominate.
So what do you think: will the manufacturers of Microsoft Word (convention 1) beat the manufacturers of Internet Explorer (convention 2) or vice versa?