I am a junior postdoc (1st year) part of a program committee in an international conference. As a member I have been assigned with several papers that I would like to delegate to subreviewers.
I have in my network researchers who are also postdocs but, they could be regarded as senior. Is it rude, or weird, to ask them to subreview a paper? If so, should I try to find PhD students or other postdocs in my range? If not, to what extended may I ask for a subreview?
Is it rude, or weird, to ask them to subreview a paper?
There is absolutely nothing rude, weird, presumptuous, or inappropriate about asking a more senior researcher to review a paper for a conference. It is an utterly standard and expected part of your role as a PC member to ask experts to review papers. Conversely, it is an utterly standard and expected part of their role as active researchers to be asked.
Of course, anyone you ask could say no. And indeed, more senior experts are more likely to say no, in part because they are likely to receive more than their fair share of these requests. That's why you should always ask for suggestions for additional/alternate reviewers whenever you ask someone for a review; more senior experts are also more likely to know who the good reviewers are!
[Checking my inbox for review requests in 3... 2... 1....]
You can always ask and they can say "no". It's surely not rude and weird; people are asked to review stuff all the time. The probability is not too low that one or more of them will say "no", but you may be lucky.
In my experience, more senior people are more likely to say "no", but of course if they say "yes" they will be the more competent reviewers. And some say "yes".
Don't be worried about asking somebody something that they don't want to do. If you ask and they say "no", it won't reflect in any way negatively on you.
I don't quite understand the premise. Are you as part of the committee tasked with finding reviewers (in which case they are not "subreviewers") or are you a reviewer and seek others to do part of your job?
I don't see anything weird in the first case. You are at the program committee. It is your job to identify the most suitable people that can act as reviewers. By contacting the appropriate people, i.e. experts in the respective field, you are doing a good job. This has nothing to do with the seniority difference.
The second case seems a bit more problematic. In my field it can sometimes happen that senior people delegate reviews to juniors. But that is usually confined to the immediate environment of the senior person (e.g. his lab or department). And it is more of an exercise and experience building and it is very likely that the review will be reviewed along with the paper again by the senior. If you would like to delegate your work to senior researchers, you can expect that it will be done by their students if it is accepted as such at all - people might not be fond of doing reviews outside of the formal channels.
