I recently received an invitation to a conference and I'm trying to determine how reputable it is. Is there a good way to go about this?
I'm assuming you are really asking how to check whether a conference is reputable (meaning not a scam), not how to check whether a conference is actually good.
Short answer: If you don't recognize the conference or its organizers, stay away.
You should already know a relatively short list of established, reputable conferences in your research area. If you don't, ask your advisor to give you such a list. (If your advisor doesn't know, you need a new advisor.)
If this conference isn't on that list, it might still be reputable, but either very new or slightly outside your research area. In that case, take a serious look at the organizing committee. If the members of the organizing committee are well-known active researchers, the conference is probably fine. Otherwise, it's probably a scam.
You mention that you were invited to submit to the conference. At least in computer science, such invitations are almost unheard of; conferences are normally advertised by impersonal calls for papers. Did the invitation come from someone you already know, at least professionally? Does the invitation mention specific technical details of your work (more than just a paper title)? If you answered "No" to both these questions, the conference is almost certainly a scam.
What I usually do is look at the list of speakers in the current and past years. If the conference is in my field, I usually can tell if the speakers are well-known and what the level of the conference will be. If the conference is not in my field, I google some of the speakers and check out their websites to get an impression.
Another thing which is often helpful to do, is to simply ask someone with knowledge of the field which conferences are good.
In addition to the other answers, it's worth taking a close look at conferences that tick several of these boxes (although some may turn out to be OK on further inspection). These can be warning signs of conferences that are basically scams, or that will be a waste of your time/money/energy.
Items 2-5 are indicators of insufficient peer review, and are problematic only for conferences that claim to publish peer-reviewed proceedings.
Items 6-9 are warning signs that the aim of the conference organizers is profits, not academics.
- Organizers, program committee members, or keynote speakers are not established researchers in the field (as per some of the other answers on this page).
- It has an extremely short review period (e.g. submissions due November 1, author notification November 10).
- You receive reviews that are very short and/or don't say anything insightful about the paper.
- The technical program committee is small, but the conference accepts hundreds of papers.
- If the conference proceedings are published or indexed by a well-known publisher, look at past editions of the proceedings and check if multiple papers have been retracted or withdrawn for plagiarism and/or for being computer generated.
- The scope of the conference is extremely broad, such that people who work in one of the areas of interest are not likely to be interested in presentations from the other areas (this can be a tactic to get a lot of submissions, at the expense of conference quality).
- The conference organizer also organizes many other conferences, on a very diverse range of unrelated topics.
- The organizer holds many conferences on unrelated topics at the same time and place.
- The organizer is also associated with one or more predatory journals, or selected papers from the conference are published in a predatory journal.
Maybe I will add to JeffE’s answer. I agree with him that, in your field, you probably have established your own list of reputable conferences after a few years. However, it does happen that you get invited or submit a paper to a conference that's outside your natural “comfort zone”. One reason is because of a joint work with other authors from that area, another may be that you are shifting the focus of your research, or you published a paper that has potential applications in another field.
Anyway, if that happens, you want to check out the organizers and speakers (keynote speakers if it's a large conference). One or two serious people doesn't mean anything though, especially if the conference is held in an attractive touristic area (Caribbean islands?). Some people accept conferences that they know are not good, if they see a nice opportunity for a holiday in them. However, if half the organizers or speakers are well known, or have well established research groups, then you're probably good to go.
Looking at the program committee, organizers, other presenters (e.g. keynote speakers) and what work they've done is one helpful approach. Asking your advisor is often quite useful.
Also consider if you've read papers from that venue in the past and found them helpful enough and high-quality enough to be citing / using as a basis for your work.
Finally, there's the Computing Research & Education conference ranking portal here which might be another signal to consider.