It all depends. Some do, some don't.

Personally, I think it's okay as a last resort, but not ideal, to squeeze, stretch, track, kern, narrow or widen the columns, etc., just barely enough to make things fit or to get rid of widows and orphans but not enough that anybody would ever notice.

If the little cheats here and there are noticeable, in my opinion, they're not working. The secret, I think is to trim/pad copy to fit, then make a variety of tiny tweaks and adjustments here and there to fine tune it.

The example you gave of increasing or decreasing text size by a point and a half is way too noticeable. There's a significant size difference between, even, 10- and 10.5-point text when the two sizes are in adjacent blocks. Rather than bumping it up a point, I'd be more inclined to increase it by a quarter point (or less), track it just slightly, horizontally stretch the letters out to 100.5 percent and narrow the column by two or three points.

Keep in mind that justified columns are all about altering the tracking from line to line to get everything to fit (one of the reasons I rarely use it, by the way). Also newspapers and newsprint are more forgiving of this sort of thing than glossy magazines that depend on a tighter, higher-quality look.

When pressed for space like that, I used to first try taking down the leading, then if there were still a few sentences that didn't fit, tighten the tracking in the last few paragraphs, and on one or two occasions, only as a last resort, squeeze the type horizontally in the last sentence (which I'm normally against), only if it was just enough of a smidge to not be noticeable. I've also been known to take down the point size for an entire article or jump (From 10/11 to 9/10).

It's probably better to make an incremental change throughout an article (say, reduce all the leading from 1 pt to, say, .7 pt), if it's not too drastic.

For newspapers, I second <b>, good news writers and editors are skilled at cutting copy to fit, or even writing to available space. This is why they invented the inverted pyramid style.

I wouldn't change the actual point size or leading of any copy within a given article, and I do my best to never scale/"smooth" text either. But I will certainly use tracking to try and eliminate hyphenations and orphans/widows.

Article to article I may play with changing the point size by half a point or so and/or the leading, just not within one piece.

It depends. If you change the text size by a half point or something that is just barely noticeable, then I guess that's okay. Either do that, or change it dramatically so it's obviously intentional. One of the local papers around here will often change the text size by one to two points (I assume) from article to article, and it's so close, yet noticeable, so it looks like a mistake.

My perfectionism and slight OCD'd nature would cause me to go completely postal if I changed the text size of body copy within one article. I'd be more likely to scale to 95% before changing the size.

Doesn't it amount to pretty much the same thing? I mean, 10-pt type scaled to 95 percent is, for all intents and purposes, 9.5-pt type. Or maybe you're just scaling horizontally.

Backing up a bit... Before I resort to various scalings, squeezings and stretchings, there's always the first-line strategy of scaling/cropping photos or using pull-out quotes, initial caps, subheads, etc., that usually do the trick. It's only for those nasty problems where nothing else seems to work that I'll resort to tweaking the text dimensions.

Yes, just scaling horizontally. I pretty much NEVER scale vertically. People (including myself) are less likely to notice the letterforms being thinner, but I think changing the height would be far more obvious, particularly when there's normally-scaled text nearby.

Those would be my first options too. After that, I'll use tracking to avoid over-hyphenation. Altering the text itself is a last resort.

I never touch the pt size or horizontal/vertical scale to make something fit. But I would experiment with column widths, tracking, leading, space before/after paragraphs, and hyphenation. Personally, I wouldn't track anything tighter than -20 and no looser than +5. It drives me crazy when other designers track things at -50 or even -100. That is not a good fix to your problem.

I never change the leading but adjust the tracking. I won't go past -30. Maybe -40 if I'm in a pinch, but I start looking at reducing pictures in articles before I go to -40. I get articles from all over the place (international pigeon racing magazine) that are written by all sorts of people. A lot of them still use two spaces after a period. Not sure where your articles are coming from but I always find/replace for two spaces. Sometimes the amount of space it frees up is handy.

I do this too