I concur with this in general, but also suggest that repetition is a cornerstone of learning. Many ideas must be revisited several times before full understanding takes effect. This specific type of repetition is not wasteful repetition. It may not be you job to teach people, but I highly doubt getting in the way of others gaining understanding is your goal either.

e. I don't have time to word-craft things endlessly, and sometimes I don't get the nuances right. It takes me almost no time to create the cross-references - the time is consumed in trying not to offend people. Sometimes there's not enough time for both.

Fair enough. Seeing as how you are very frequently the person who posts the cross references (which btw, I really appreciate) I would like to propose this as a template for future "this is a repeat" posts (I certainly hope other jump in if there is a better way of putting it than my template):

This article is something of a classic here on HN. There have been some good discussions on it previously (see below). The comments in those articles may help provide some perspective for the discussion here.

$LINKS

If the repetition doesn't link to previous discussions, it definitely is wasteful.

It's like adding a comment without having at least skimmed through the already existing comments.

Since it is people who do the understanding, some repetition, while wasting bytes or words[1], certainly helps maximize reader comprehension. Even math and CS journal papers quote things, not just put pointers. That is wasteful repetition don't you think?

I look at it as an optimization problem. There are at least two variables -- number of words and reader comprehension[2]. The goal is information transfer between people. To minimize or maximize any one of those variables may result in non-optimal information transfer. Instead there may need to be some repetition rather than pointers for some things.

[1] There are serious questions at this point whether at the scale of HN discussions there is such a thing as limited resources for data storage, bandwidth, etc (and given the level of intellect here, even reading time is almost trivial for a lot of posts).

[2] There are lots of confounding variables, such as the intelligence and prior knowledge of any given reader, the eloquence of the writer, the complexity of the point being made etc.

No, that's not my assumption at all.

I find it very useful if someone summarizes previous stuff, or reformulates hard-to-understand (e.g. badly worded) previous comments.

However, you should do that consciously. There's no sense in writing a comment that essentially just repeats what others already have written in better words than you'd ever do. Doing that is a waste of time not only for you (the writer) but also for all the readers. And it happens a lot, simply because people are too lazy to skim though the previous discussion.

The above may be wastes of your time or energy or limited word count, but they are not wasteful to others (in fact, the opposite is true -- someone may actually be benefitting!). This is my point: what is wasteful to you may be beneficial to others.

You can downvote it, or wait until stories have been around for a bit so others will have sorted for you (and only read the top comments of course).

This is of course possible, and I don't object that as long as they know they are reiterating. However, this is only possible if people at least skim over previous posts, which is usually not the case, and which is why hints to previous discussions are not only helpful but necessary to avoid wasting time.

> This is my point: what is wasteful to you may be beneficial to others.

Repeating something for didactic reasons is sometimes indeed no waste of time for the writer. However, if the writer then publishes this, despite other people already wrote that stuff up in a much better way, that person wastes the time of the readers by filling up the comments with, let's face it and call it by its name, garbage.

Simple to implement; accumulated wisdom is not lost.