It is not good English. Before it is too late and becomes common parlance here, I suggest that another more suitable word be used in its place.

I propose "dialectical". At least the literal meaning is "discussiony". You could also call such questions colloquial.

As an American I consider it my birthright—nay, duty—to promote the continued evolution of our language in whatever direction its speakers take it.

Only half-serious, of course (and I know this is not a web site exclusively for Americans) but I guess that cultural norms differ from country to country. For instance, my impression is that this kind of prescriptivism is more common in France.

Regenbogen, I think you'll come to realize if you take a moment to check that I have spelled the word "discussion-y", thereby acknowledging that it is not proper English but also using the word to fill a niche that has popped up on a website where discussion questions are in violation of the rules. That is, "discussion-y" means "in violation of the rule against discussions."

Could you add some stuff to the FAQ? Something explaining the consensus on discussion questions and also add an anchor so we can link to it?

I think the word dialectical is way to politically loaded.

It's clear that the internet and its associated culture has led to a general expansion of the vocabulary for most languages. Even in French! (Though with some interesting twists, e.g. FAQ certainly did not originate as an abbreviation of Foire Aux Questions.) It's perfectly natural for MathOverflow to give rise to such new words. Resisting this is an exercise in futility.

As used on MathOverflow, discussiony has a very specific meaning that isn't captured by dialectical, which usually refers to the dialectic method. The term discursive is much closer, but still a bit off since it is often used as a synonym for rambling and may be wrongly perceived as a derogatory term. I think discussiony is actually just right for MathOverflow.

Hmm, there are a few, but I'd have to find them first.

No, precisify is just criminal.

Because obviously "complication" wouldn't serve the purpose equally well. It's too clever by half.

Because discussion-y or discussiony is specifically in reference to the discussion rule.

Mariano, was it a native French speaker who said "precisify"? The French verb préciser means something like "to clarify by adding detail" (quite different from the Spanish precisar, but not so different from the Italian precisare, if my dictionaries serve me well). I've heard French speakers say things like "let me precise that for you", when explaining a piece of mathematics. So I could understand if they guessed that "precisify" was a genuine English word.

Personally, I love it when non-native English speakers say things like that.

I like "discussion-y"/"discussiony". "Discursive" would work, I guess, but it seems too academic and formal, and "dialectical" even more so. I like to think of MO as, as many others have already said before, an international online mathematical tea time. Tea time is (or should be) something casual and friendly. So I prefer more casual language over more formal language, at least when the latter is not necessary.

The reason "discussiony" sounds bad to many English speakers is that there is a condition on the types of words on to which "-y" attaches that is not satisfied by the stem "discussion." In most languages, affixes are not added to stems willy-nilly. For instance, we can not add a plural suffix "-s" on an article "the." There are conditions on the part of speech that the word must be, its size, etc, that restrict what things may be added.

The "-y" suffix is a derivational suffix which may apply to either a noun or a verb to make them adjectives. Most nouns and verbs to which this suffix attaches are monosyllabic. On verbs, for example, show - showy, jump - jumpy, risk - risky, push - pushy, touch - touchy, sleep - sleepy, etc. On nouns, for example, hand - handy, wood - woody, spike - spiky, mouse - mousey, sun - sunny, etc. The set of nouns taking this suffix tends to be more restrictive than the verbs. Many of the nouns could actually be considered verbs, e.g. sun or hand or spike, in the list above. However, one general thing among all roots taking this suffix is that they are monosyllabic. "Discussion" is not monosyllabic and so it sounds ungrammatical when one says "discussiony."

One does not need an "academie anglaise" to decide what is or what is not grammatical. Each person has an incredible amount of grammatical knowledge that they know subconsciously through having grown up speaking English, or whatever language they grew up speaking. Your intuitions serve you well here. If it doesn't sound right - ungrammatical - then it probably violates some rule that one internalizes about English or is statistically odd. The job is then to identify what rule is broken.

Note that this is distinct from the diminutive suffix "-y" which changes adjectives to nouns or nouns to diminuative nouns, e.g. brown - brownie, quick - quickie, dog - doggie, etc (spelling is irrelevant here, both "ie" and "y" are pronounced [i]).

Not all your readers are mathematicians. I'm a linguist.

It has always struck me that there are more interesting things to do, and more annoying things to try and ameliorate, on MO, than indulging in some hankering for Hochdeutsch. Yes, it is not a proper word. No, I don't think it is a big deal.

Thanks cdicanio!

To others: It is possible that good linguistics and good math may go hand in hand. We must not forget that Gauss the prince of mathematicians(at any rate the force behind modern number theory) was also immersed in linguistics. "Complexify" has a natural context and is legitimate, and serves a mathematical purpose. Discussion-y is on the other hand not a mathematical word; it is general parlance. So one should follow what linguists say about that.

So, cdicanio, the problem is that so far there is no alternate word. How about discussive, for instance? If there is a better word, hopefully it will be easier to convince (reasonable) people.

@fpqc. I feel honored to secure a place at least in your trash. Thanks to you a lot.

In any case, I am not policing anything. I just pointed out my discomfort, and if others find the word to their comfort, they are of course free to continue using it. Who am I to stop anyone!

Oh yeah. Doing a search for "jokey" in google videos or youtube and watching the very first result clearly shows your meaning in the context of mathoverflow.

I'd like to justify "discussiony" on the basis of artistic license. It conveys its meaning quite efficiently and to me this is much more important than whether it sounds right in a strict sense. Remember what Hilbert said about mathematicians and poets!

After reading cdicanio's post, I realized that "discussionish" would actually be a lot more like an actual English word. Probably too late now, though.

Yesh, it shertainly doesh.

The word "Noetherian" can only be pronounced without excessive strain if you pronounce the "Noether" part incorrectly. I will worry about "discussion-y" after we fix that mess.

No, but following it by "ian" rather than "ish", like in German, requires one to pronounce it incorrectly.

Either you have to pronounce the name with the emphasis on the wrong syllable (read: second), or you have to change the way that you say the word entirely! Try this when you get home:

Noether

Noethersch (German) (Corrected!)

Noetherian (English)

Note how the emphasis changes! This would be like pronouncing your last name "Wib-sturrr".

(actually it's noethersch in German, not noetherish)

(Incidentally, what's the correct German way to pronounce Noether? I guess the oe part should be pronounced like ö, and not like "oh", as it is commonly pronounced by English speakers?)

(@Kevin: yes, we pronounce "Noether" like "Nöter". @fpqc: not in this case. Her name really was Emmy Noether)