More often than not, one of my friends taps me on the shoulder while we are coworking to ask me a question or tell me something. As such, I had to reiterate the headphones rule to which most programmers abide. In doing so I discovered this site, but I believe the rule can be applied more realistically as follows:
- Always send a message instead of disturbing.
- Headphones fully worn means send a message and expect a response when I am available.
- Headphones half worn means send a message and if I do not respond quickly, a necessary disruption is acceptable.
In order to maintain a high level of productivity it is much more appreciated to simply send a message or schedule a time to chat. This will allow the developer (or any profession really) to remain focused on the current task.