I have been invited as a Guest speaker to a scientific workshop at a University. I know there will be faculty members but will there be students present as well? This is my first time as a Guest speaker, so any information of what happens in such events would be helpful.
The answer to this question will vary from school to school. Typically speaking, you could expect faculty, staff scientists, post-docs, and graduate students at a generic guest speaker's presentation. As such, you might aim your talk for an audience of educated scientists with familiarity to your field (but not experts of the field).
If you want more certainty, you could ask the organizer who invited you what audience you can expect.
If you are comfortable adapting to your audience on the spot, and you are comfortable being somewhat informal, you could ask for a show-of-hands at the beginning of your talk. E.g.: "Show of hands, how many post-docs are there in the audience? ... Graduate students? ... any undergraduates?"
This varies tremendously by venue, as it depends on exactly why the talk is being held, is influenced by who is funding the talk and why, etc.
As an example, one set of public talks may be held as part of a series for "public and community outreach". At these talks there will be a mix of a few scattered faculty members, students of various programs, and up to half will be members who live in the surrounding community, including retired people, professionals with only a vague general interest in the topic, business people who might have an interest in the field, etc.
Another set of talks might be purely directly at students. There may be only a few faculty members (1-2 wouldn't be unusual), mostly undergraduate students from the specific hosting program and a few from related/other programs (who may be required to be there, or receiving extra credit for a class), and a few grad students (who are there because they are really interested, and/or may be hoping for some fee snacks). Other talks are held specifically for grad students, and there will be very few undergrads (if any), and yet another set of talks might have mostly faculty, post-docs, staff, and a few scattered grad students.
Administrators (deans, department heads, etc) attend some types of talks, but tend not to be found at others.
However, it is always acceptable to ask your host about the predicted audience, and they usually have a pretty good idea of who can be expected to show up. You should certainly be prepared for this prediction to be less than perfectly accurate, and the general assumption is you'll have a range of intelligent, interested, people attending, though few will be anything resembling experts in your specific area.
If your workshop has limited attendance and sign-ups, you could even send out a survey to try to learn about your audience, but this a luxury that's not usually available if it's just an open talk.
This is really hard to answer since it depends on so many factors.
In our relatively small math department, the average guest talk had a small handful of faculty, and maybe 6 students or so, and it was usually those of us who spent a lot of time on campus because of the times of the talk (mid-afternoon).
If you want any metrics that could help determine, I'd ask the host:
- what time the talk is (the further from noon, the less people you should expect)
- if they know of any professors/instructors offering extra credit to students if they go to these talks (in a couple cases, a graph theory talk filled the classroom, another had to be moved to an auditorium).
Also it depends on the general attitude towards your topic in the school. For example, are you a Knot Theorist going to speak at a small liberal arts school? I wouldn't as expect many to come, compared to if you were speaking at a large polytechnic university.
In the end, unless you're worried about having enough handouts, or something like that, don't waste brain space thinking about how many people. You can give a talk to 1 person the same way you can give a talk to 1000.