I'm now a member of my department's colloquium committee. Our task is to make a great colloquium series. I thought that the first step would be to come up with an appropriate definition of "Mathematics Colloquium." Standard dictionaries are not too much help:

```
Colloquium: n.
1. A usually academic meeting at which specialists deliver
addresses on a topic or related topics and then answer questions relating to them.
2. A conference at which scholars or other experts present papers on, analyze,
and discuss a specific topic.
```

So here's my question: What is the ideal definition of a mathematics colloquium? Of course I know a bunch of things that make for **bad** colloquium talks, so I'm interested in knowing the definition of a good or great mathematics colloquium.

actuallyhappens? And what geographical variations are you or aren't you interested in? $\endgroup$ – Yemon Choi May 2 '15 at 15:179more comments