On the site, we generally have been trying to add "Welcome" comments to posts by new users to attempt to get them to stick around on the site and contribute more. On the other hand, officially, comments are exclusively for suggesting improvements or requesting clarification. So, as moderators, should we be removing these "Welcome" comments? Or should we be leaving them up?
Comments should serve a purpose:
When should I comment?
You should submit a comment if you want to:
- Request clarification from the author;
- Leave constructive criticism that guides the author in improving the post;
- Add relevant but minor or transient information to a post (e.g. a link to a related question, or an alert to the author that the question has been updated).
A comment that just says "welcome!" doesn't do much; a comment that welcomes the user and provides them with useful information - whether that's in the form of a question for the author, identification of a flaw in their work which they can correct, or a link to more information on the site - is considerably more useful.
But regardless of the initial utility of the comment, most comments will not be so useful days, weeks, months down the road. And just as a "you should fix that link" comment becomes noise as soon as the link is fixed, a "welcome to the site!" comment loses any value once the author is an established member of the site.
We recently implemented a built-in New Contributor indicator on posts - and that ages away after a week, ensuring that it can serve its purpose without generating perpetual noise. Similarly, the canned comments generated via /review/low-quality quietly disappear after a couple of days if the post remains visible on the site. In both cases, we try to balance the value of providing feedback with the cost of superfluous text shown to every subsequent reader.
When to delete
For pure welcoming comments, this suggests that once the comment is more than a day or two old (at most!), they should be removed: the author has been welcomed, the space can be better used for more contemporary comments (or provide slightly more room for answers).
For comments that provide some other information along with the greeting, the decision to remove should be based on the current relevance of that information: have the suggested improvements been made, has the provided information been consumed? If so, remove.
See also: A guide to moderating comments
I differ only on the duration of the comments.
The standards of the SE-verse are well established. The "culture" of each site is still able to develop in its own way. Here on CSEducators we are a smaller, and slower, site than many, and the culture is less formal than some others. Welcoming comments have been a part of our default behavior from the beginning. This is well before the general "New Contributor" system was instituted.
The new system for new contributors was built with a seven-day timer on it. Without knowing why, I'm left to conclude that they did their own research an determined that a week was a reasonable choice. Often a new user posting here may not return to the site for a few days. This is increasing likely for new users posting answers than questions. It is, however, also increasingly likely during the certain parts of the school-year, such as testing periods and term endings and beginnings. Keeping all that in mind, I'm of the opinion that using the timing of the "New Contributor" alert serves well as a guide for removing the purely welcoming comments.
As Shog9 has pointed out, "comments should serve a purpose," and that purpose can be "community building" as well as suggesting improvements to the post. In both cases, once the comment has served its purpose, the comment does become noise. The SE community team thinks that the "noise" from the new contributor system is acceptable for a week. The noise from the welcoming comments ought to be acceptable for the same time frame.