About demanding work from askers

Question

I only found out about MSE around the end of my degree, so I didn't get to ask that many questions. However, had I known about it earlier, I could see myself wanting to ask questions, having thought about them, but having nothing tangible to say.

Forcing me to show my work, would be forcing me to show absolute gibberish with no hope of salvation and possibly, as a consequence, get my question closed as being unclear.

Recently I saw this happen with another user (who is clearly willing to make an effort). The question was closed as being unclear, even though its clarity is transparent and judging by the OP's comments, sharing his work wouldn't do much good either.

This question is specifically addressed to anti-PSQ people.

What could this user have done differently, considering their technical knowledge limitation (i.e. not having any proper work to share), to ask the question in a way to minimize the chances of it being closed?

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Edit: Clarification - Many people mentioned context as if somehow lack of context was the reason why the question was closed. I don't understand this. It was hinted by a user that, despite the fact that officially the only reason for the question being closed was that it was unclear, the real reason was lack of context.
If this is the case, then one very important assumption behind my question doesn't hold. People really should choose the proper reason for closure, how else are people supposed to know how to ask a good question?

Answer 1

Let us look at the question in detail.

Let C be the class of all subsets of $\mathbb{R}$ which are either countable or are the complement of a countable set. Show that C is a $\sigma$ field.

Here OP could recall what being a $\sigma$ field means. It seems OP knows this, but spelling it out would

• make the question accessible to more users and avoid risk of mismatched conventions. (For example, I'd know the substance well-enough to answer, but I was not certain what a $\sigma$ field is. Yeah, I can look it up, still.)

• help clarify their own thought-process.

• count as context pleasing anti-PSQ people (to stay in tone with your question) and reduce the need for showing work.

• allow prospective answerers to write an answer exactly matching their definition, including choice of letters etc. At that level of misunderstanding it might be useful.

This is what I have right now:

(i) $\varnothing$ $\in$ $\emptyset$ since $\emptyset$ is countable .

What in the world is that supposed to mean and how does it related to the task at hand? Likely OP wants to show that the emptyset is in C but that's not what's written. (The original is somewhat better.) Note had they spelled out the definition that they implicitly refer to it would be clear what they even want to do. As written it's not at all clear. Yeah, I can guess it, but that's not the same.

(ii) A $\in$ C since A is countable since given C is countable.

What is $A$? Is it the name of the full set in the definition OP keeps referring to but did not bother to state. Or, is this a generic subset and a totally misguided attempt to show the 'complement' part. (On second thought, I'd guess this, but my honest first guess was the other option.)

(iii) $\bigcup^\infty_{i=1}A_i$ $\in$ C, is true since $A_1,A_2$, are countable then so is $\bigcup^n A_n$ since a countable union of countable sets is countable.

Here it is relatively clear what is intended.

I need help understanding (ii) and (iii).

To sum it up, as far as I am concerned it'd suffice they had recalled the definition as they have it in front of them before embarking on their attempt that keeps referring to it.

Answer 2

Rather than focus on what the OP of the Question could or should have done "better", I'd note your exchange with the OP, eventually including in one Comment:

You're confused about something, but I can't tell what it is.

I'm in complete accord with your effort to engage the OP. Your tone was constructive and directed attention to a threshold issue, is $\emptyset \in C$?

The off-topic close reason is something I resort to when a Question's author does not engage at all with the requests for clarification (I often indicate several ways to add context besides "show your work"). This is not the issue here. Rather the issue is being unsure what the OP is hung up on in trying to apply the definition of a $\sigma$-algebra (or "$\sigma$ field" as the OP put it).

If the intent is to help this particular poster, I'd be unclear how to do that. So I'm validating the present status of the Question being closed for unclear what you are asking.

Taking the OP's confusion out of consideration, I'd look to see if the $\sigma$-algebra construction (countable $\cup$ co-countable) has been verified in an existing Answer to another Question, and pre-emptively note that in a Comment. If it hasn't been dealt with thoroughly at some point in the past, it is an interesting/important enough fact to deserve a proof now.

To go that route I would give the OP a day or two to revise and edit the Question, and then (assuming no satisfaction) I'd turn my hand to editing it myself.