Icons are mnemonics, not signposts.<p>Icons alone are never sufficient when someone encounters an interface for the first time, you should always include a text label.<p>New users to an interface will read the text labels, and after time, the icons become a quick mnemonic for them to locate functions they've accessed before.<p>Even more important than visuals or text is location. Our spatial memory has a higher priority than either. In repeated user tests, I've observed that once people become used to a button resting in, say, the top left corner of a UI, they will click there again for the same function, even if the button itself has changed.<p>Don't worry too much about the exact semiotics of your icons. Just keep them reasonably meaningful, clearly distinct from one another, include text labels, and be consistent with where you put them.