I am organizing a small workshop which is over subscribed. We will have to reject a few applications. The worst applicants are easy to spot, but there are a few borderline cases, and I'm afraid that a few unfair decisions will necessarily have to be made.

To minimize the damage, I would like to know how many of the registered participants who we accept will actually show up, so that if I am aiming at X actual participants, could I safely accept X + dX?

I have noticed that several name tags always are left unclaimed at small meetings, because of people not showing up. I would like to know how to estimate how many people I can expect not to show up.

I am looking for answers from people who have organized (preferably small) meetings and have first-hand knowledge about the typical numbers.



So the week of the workshop came and I can give you attendance numbers. It is good that I didn't overbook since we got 100% attendance (49/49 registered participants). This is despite the event being free of charge (some people suggested the attendance would be lower for free events). Some of the things that we did that may have helped secure such good numbers are thorough screening of applications and asking for confirmation upon acceptance of the applicant. For instance, we weeded out a few applicants who were unlikely to show up unless we paid for their travelling and a couple of accepted applicants told us that they would not be able to attend, a couple of months in advance of the workshop.

  • You should also explain whether there is another track/workshop/conference in parallel. If people can switch freely between these alternatives, an estimation might be way harder. (I am not an organizer but I have seen this several times, that some events are extremely well-attended while others can become nearly empty)
    – J-Kun
    Commented Mar 1, 2018 at 9:40
  • I have organized some small meetings. Everyone who had registered showed up except some people who (or who's family members) were sick. I don't think you can extrapolate hard numbers from experiences others (in different disciplines, countries, institutions) have had with small conferences. It would work better with really large conferences since with those you can actually rely on statistics. I suggest you assume everyone will show up and possibly establish a system that allows people who wanted to register but were rejected to attend if someone cancels.
    – user9482
    Commented Mar 1, 2018 at 9:42
  • Is it a free event, or with low cost of application? How wide was spread the ads for this application (only university, twitter, online forums, group and associations... ) ?
    – llrs
    Commented Mar 1, 2018 at 14:09
  • @Llopis It is free, but the advertising has been targeted. I have some weird applications but most are from people in the field from reputable institutions.
    – Miguel
    Commented Mar 1, 2018 at 14:17
  • Is this at a highly reputed institution? Is the workshop tied to a visible publication, such as a special issue? Are the participants well-known and interesting? These variables are important incentives to actually attend. Commented Mar 1, 2018 at 15:26

4 Answers 4


I am afraid that, especially for a small meeting, the variation of how many do not show up will be too large to be useful. For example, if I am organizing a 50-person event I would expect that anything from 2 to 10 would be a "normal" number of no-shows. That is, if you really can't have more than, say, 50 participants you can't really safely overbook at all. However, note that oftentimes a few participants more don't really hurt, but of course this depends on your infrastructure and plans for the meeting.

Some further considerations:

  • Generally, free events have a very large number of no-shows (sometimes in the 50%+ range, from what I have heard) while paid ones do not. This has led to some meetings I know introducing a nominal attendance fee, just to make sure that people think a little before signing up. Some other meetings have also tried to levy a fee only if a registered participant does not show up, but I am not sure how well this works and if it is worth the administrative and inter-personal hassle.
  • Note that no-shows are often not independent events, statistically speaking. For example, if you have a bunch of participants from the same group / team and they have an unexpected important deadline come up, they all will cancel at the same time.
  • If you have a very small meeting and you know (some) of your participants well you can attempt to use this to make a stab at estimating no-shows. For instance, I once planned an event for about 30 people, and I knew that some of the senior professors who initially expressed interest where <50% to actually come. I also knew that for some fraction of the industry participants an important client meeting may come up making them cancel last-minute. Based on this information I decided that 35 registrations for a 30-person meeting was fairly safe (we ended up being 28).
  • 2
    An alternative for we-charge-you-if-you-don't-come is to charge a fee and then refund it upon attendance (often called 'motivational deposit' in other contexts). Is this something that can work in the context of a meeting? Or is the fact that it's primarily institutions that are footing the bill make that a non-starter?
    – E.P.
    Commented Mar 1, 2018 at 23:02
  • 2
    How about operating a waiting list, and telling those accepted there is a waiting list? That might mean that those who know they can't come are more likely to let you know in advance.
    – Jessica B
    Commented Mar 2, 2018 at 9:06
  • @JessicaB We do have a waiting list (which I think is a good idea). I will periodically remind attendants that there are people awaiting a chance if they can't make it. I am more concerned about people who will not let me know at all that they're not coming.
    – Miguel
    Commented Mar 3, 2018 at 7:01

Having "no shows" at a scientific conference is common (for a multitude od reasons). I could not find a general statistic of this phenomenon and I guess that the numbers vary a lot depending on the field and also on type of event.

Here is one thing I found: The Australasian Telecommunication Networks and Applications Conference, (ATNAC) published a welcome address in IEEE where is says that

The conference paper statistics were: Pending (no manuscript): 3; Withdrawn after review: 0; Rejected: 33; No Show: 4; Published: 40; Total valid: 78; Published Ratio: 51%; Acceptance Ratio: 56%.

(The numbers in the pdf are different, this is a note on the website.)

Hence, there where 78 submissions, 44 got accepted and 4 of them did not show up at the conference.

Note that the above example is about no-shows of accepted presentations. No shows among registered people without contribution is usually much higher.


I think it really depends on:

  • which academic field
  • how much the registration costs
  • how accessible the location is (major city in a country with many scholars of the field vs somewhere more remote)
  • (other factors?)

and there's no general answer.


Generally if an academic signs for a workshop, they will definitely attend, unless something comes up that stops them. Why would I bother registering if I'm not attending, I have nothing to gain?

Nevertheless, you should expect the number of audience to shrink starting from the first day, especially if they get their proof of attendance. In my experience, if a PhD presents on the third day he will probably have three to four people listening. That is painful but hard to avoid.

  • 11
    This sounds right, but certainly it is not. Every large meeting has a lot of no shows. Believe it or not: people sometimes forget that they registered, sometimes they change plans and forget (or don't care) to let the organizers know, sometimes the travel arrangements do not work or, other people miss a conference due to visa or immigration problems…
    – Dirk
    Commented Mar 1, 2018 at 10:05
  • 5
    This does not really answer the question. Contrary to your suggestions, I do know from experience that many people don't show up, for a variety of reasons, some better justified than others. I'm just interested in an estimate for the numbers. Again, contrary to your statement, by registering for a (free) meeting you have everything to gain and nothing to lose, assuming there are no consequences to a no-show (there usually aren't). If you register you can either attend or not; if you don't register you loose that possibility.
    – Miguel
    Commented Mar 1, 2018 at 10:52
  • I think you're confusing "assist" and "attend" which are somewhat flipped in languages other than English. Commented Mar 1, 2018 at 17:33
  • 1
    Your reference to proof of attendance suggests that you feel that most academics attend conferences mostly to get an expenses-paid holiday. Maybe that's true among your acquaintances but it isn't the impression that I get. Indeed, although some conferences do give proof of attendance, I don't think I've ever been at an institution that's demanded to see such proof before paying my expenses. British universities, at least, seem to assume that their employees aren't engaging in blatant fraud Commented Mar 1, 2018 at 18:01

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