Please Don’t Call
I don’t like receiving most phone calls when I’m at work.
There are two exceptions: one for my family, and one for department business like a colleague working on a service project. Most other calls should either not happen at all or should be scheduled in advance.
It would be different if the phone would say “he’s busy now, hold on while he writes down what he’s thinking about.” Instead, you’re supposed to drop everything in order to think about something completely different for an extended period of time - often something useless like a salesman trying to sell me a clicker system for a graduate field course.
Unless I’ve got a big block of free time after the phone conversation ends, it’s unlikely I will be able to reach the same level of productivity again that day. What makes it really bad is that all of this could be avoided by scheduling the call in advance. Rarely is it urgent, and it doesn’t cost me much to take your phone call when I’m expecting it. Even worse, unless you’re taking notes, you are likely to forget what was said in the conversation. Even if you do take notes, there is no guarantee that you will get it right, because you’ll be writing down what you think I’m saying. With an email, you can read what I’ve written about what I’m thinking.