So, you have been asked to comment on a paper at a conference. In all likelihood you have not done this before, and for many you have never seen it done either. In what follows, I offer some suggestions as to how to approach commenting at a professional conference.
Congratulations on becoming an important part of the creative output of an academic research program! Commenting on a paper is the next most important role to presenting a paper at a professional conference. Paper writers will be relying on you to do two things: (1) help the audience identify and understand salient features of the paper, and (2) be the key person to ask critical questions that will help the presenter think about, improve, and expand their paper. While this is a shock to most speakers, the audience at a conference might not be well equipped to help the speaker think about their paper critically. Of course, it is nice to simply provide new ideas to an audience, most speakers are actually looking for help in assessing the thoughts in their paper in terms of clarity and closeness to the truth. This is why your job is so important.
First, you should take your job as a presenter seriously. This is especially important because commenters are also generating creative output. In many cases, commenters have been noted for their philosophic skills, thoughts, and critical abilities. In some cases, the commenter can be a greater benefit to an audience than the speaker themselves. As a result, you should dress the part of a professional, write your comments in a professional manner, and be kind and courteous to your speaker and the audience.
Second, you should invest some time in your comments. I recommend the following format for a 5 minute commenting session; I also recommend that if you have 10 minutes you simply double the formula below. (5 and 10 minutes are common lengths for commenting.)
Finally, remember that your comments are part of your own creative output; so, be sure to make them such that you are proud to present them in front of an educated set of peers.
Here are some final thoughts that might also be of some use in thinking about commenting.
First, people are typically focused on the speaker; in this way, you are simply helping the audience understand and think about the speaker’s paper. This means, audience almost always view your work as good, since it helps them and since they’re not there to evaluate you; this takes a lot of the pressure of speaking off of you.
Second, some commenters take the time to thank the speakers for their papers and to say a few words about the merits of the speaker as a thinker/person/contributor to the profession. This is by no means a requirement; in some cases this comes off as nice and thoughtful, in others it comes off as disingenuous.
Third, I cannot repeat enough that it is your main job to help the speaker. The best way to do this is in the part of your comments where you help the audience understand the speaker. That said, most speakers are extremely thankful for the fact you have read their paper and thought critically about their paper. It is very common for speakers to acknowledge commenters in the final versions of their paper. This is a good way to participate in the creative process.
Finally, commenting is an excellent way to impress people and make new contacts in a much lower stress way than presenting. Be your best self when commenting and people will seek out your thoughts in the future.
Most commenters provide their speakers with a short summary of their critiques a couple of weeks before the talk. This gives the speaker some time to consider responses. It is considered very uncouth for the speaker to change their initial talk in line with the comments, but it is equally uncouth to blindside a speaker. Thus, I strongly recommend you get in contact with your speaker as soon as possible, and you provide them with some idea the line your critiques will take a week or two before the presentation.