# Bite-sizing homework

Well, meta posts about "homework" keep on coming, but we still don't seem to have a solution that sticks, so I'll give it another shot. For what it's worth I think the current system isn't so bad that we need to go back to the drawing board, but that there's also room for improvement.

My suggestion is to use this question as follows:

Post answers containing a short, self-contained statement on the topic of the homework policy. Keep these as close to one line as possible. I'll put up a couple of my own to show the format I have in mind and get the ball rolling.

Vote according to whether you agree or disagree with the statement. This is of course the normal voting process for meta.

My hope is that this can break up the question of homework policy into bite-sized chunks. Some items we will have good agreement on - these can be either implemented in the case of positive agreement, or discarded in the case of negative agreement. Other items will be debated - these can go to other meta-questions for further discussion.

• As discussed in the chat earlier, the hope is that people other than me will also add answers. I don't think I've been particularly thorough in covering the possible answer space of this question, so if you think of something, please add it! Jul 15 '14 at 17:56
• Questions like this are On Topic. Jul 21 '14 at 10:19
• Welcome to Physics.SE! Please refer to our new set of guidelines for help on how to write a good homework question.
– Jim
Jul 29 '14 at 14:10
• Just a note that this is currently being discussed in Physics Chat. Jul 29 '14 at 15:53
• I think physics.Se can have two elementary and advanced section like mathmatics and mathoverflow. Jul 29 '14 at 23:31
• @MinimusHeximus there is a physics overflow site.
– Jim
Aug 5 '14 at 14:00
• @Jim: both math sites are in stackexchange. in math.se homeworks and simplest questions are allowed (provided some effort is shown). In mathoverflow just advanced math research questions are allowed. In physics.SE homeworks are not allowed also it does not seem research-oriented. I think a more low-level physics site and a more advanced one are needed. Aug 5 '14 at 14:09
• @MinimusHeximus Math.SE does math. If they didn't do math, they'd have nothing left. Thus, when they allow homework questions, they expect to have to do math because it's what they're all about. Similarly, we do allow homework questions; but we expect to do physics as it's what we're all about. We do not allow homework questions where it only wants us to do the math of some problem for someone because we are not Math.SE and doing someone's math for a physics homework question is not about physics. If a homework question asks us to do physics and not just math, then it is allowed
– Jim
Aug 5 '14 at 14:24
• @Jim: I'm not a physicist. But it seems a high school question will be closed in physics.se. So I think a wider range of good physics questions should be allowed somewhere. btw, just calculation, or bad questions are closed in math.SE: math.stackexchange.com/q/758382. But math.se now is a good source of any math problem or question for a google visitor which has help it be big SE site: stackexchange.com/sites#. I think there should be a wider physics site so it can attract more people not just experts. Aug 5 '14 at 14:40
• @MinimusHeximus Ok, do some research; find out what kind of questions we usually close that you would rather not be closed. Ask yourself too, "is this question really asking about physics?". Then think about posting a question on our meta, "Should we allow these types of questions?" Couldn't hurt, right?
– Jim
Aug 5 '14 at 15:47
• @Jim: It was a suggestion which has been done for math side and seems to make this site more helpful and successful. but it seems you are talking about how to live with existing restrictions. see this page: physics.stackexchange.com/questions/tagged/… many questions closed. This means that there a lot of questioner who cannot get an answer in physics.se. So it seems reasonable to create an elementary physics site for them. Aug 5 '14 at 16:10
• @MinimusHeximus Ok, well I'm now unsure what the problem is. I have nothing against helping people understand physics for homework problems so do what you think is best and I'll probably agree if it's helpful
– Jim
Aug 5 '14 at 17:12
• I think an elementary site for more elementary questions and an expert site for experts will help both beginners and experts. The site can then be also an encyclopedia of answered elementary and advanced physics problems, just like math.se and stackoverflow. This is just a suggestion. If dividing the site is not possible I think a wider range of questions should be allowed: stackoverflow is a good example for this. Aug 5 '14 at 17:33
• It seems physics is more interesting than mathematics. So why physics.se has attracted less users than math.se? there is somethong wrong with it. I think the problem is with the range of allowed questions. dividing beginners and experts may be a solution. Aug 5 '14 at 17:46

Questions that can be summarized as "please solve this exercise" or "please plug these numbers into an equation for me" are OFF topic.

Questions that can be summarized as "Please explain what this aspect of a solution/derivation means or why it makes sense" are ON topic

Questions that can be summarized as "I was working on X and didn't understand why Y isn't the case" or similar are ON topic.

• I was thinking about how this is worded and decided to retract my upvote. Questions that say "I don't understand why Y isn't the case" can easily be a rephrased version of Kyle's "reasoning" question below. Someone could post a question saying "I was working on '10x+5=27' and didn't understand why 'x=12' isn't the case." Or, they could say "I was working on that problem. I did '10x=22' and thus 'x=12'. But that is not correct. Where has my reasoning gone wrong?"
– Jim
Jul 15 '14 at 20:29
• Essentially, we need to take care that the wording we choose in these answers doesn't allow for users to cleverly disguise a "check my work" or a "do my work for me" question
– Jim
Jul 15 '14 at 20:30
• I like this wording better than than "'please check my work' is off-topic." Consider this question of mine, which I considered on-topic when I asked it (though I may have worried that the homework police might close it). I strongly believed that I was making a silly mistake, but I couldn't find it without another pair of eyes, and I considered it possible that there was actually something interesting there.
– rob Mod
Jul 15 '14 at 22:35
• @rob The difference between these two types of questions as I see it is that one is a long series of steps with (probably) a mistake somewhere buried it, whereas the other attempts to isolate the mistake or problem as much as possible (while perhaps still giving some context) and asking for assistance. IMO one is on topic, and one is not. Jul 15 '14 at 22:40

Questions that can be summarized as "I want to solve this problem but do not know how. What relevant physics do I need to research/learn to solve it?" are ON topic.

• I'd like ton submit as an example 2 recent questions which address without naming it the field of "inverse problems" (1 and 2). They have been closed. I believe pointing the OP to the field of inverse problems would have been more relevant.
– Joce
Jul 18 '14 at 9:43
• @Joce these questions should still be closed because they do not show the expected level of prior research. In the second one you linked, the asker even specifically knows they are looking for equations for a parabolic path. Typing "equation for parabolic path" into google immediately gives the derivation, examples, understanding, and background for parabolic motion in just the first three hits. If these people can't be bothered to do the most basic google search to find their answers, then we couldn't help them anyway
– Jim
Jul 18 '14 at 13:54
• Image link to Joce's question no. 2 for <10k users. Aug 11 '14 at 12:12

The current policy is summarised as "we do accept homework questions, but only if X, Y, Z". It would be better to move to a policy that says "we do not accept homework questions. However, if you do X, Y and Z it will not be a homework question any more and we can accept it."

• I agree with this one. Jul 27 '14 at 14:42

Questions which can be summarized as "This is the statement of an example problem. (Perhaps the "simplest" and/or the "most interesting" case I have been able to think of at the moment.) Rather than solving it (which I may or may not be able to do myself) I'd like you to point out some useful "standard", "technical" terminology, including some name for the general class of problems to which my specific example case belongs, such that I can educate myself further." are ON topic .

• A bit wordy for a summary perhaps, but I guess you can't do justice to every question in pretty one-liners.
– ACuriousMind Mod
Jul 18 '14 at 1:08
• @ACuriousMind: "[...] I guess you can't do justice to every question in pretty one-liners" -- Indeed. Pretty much as you shouldn't just slap the (notorious) homework tag on any given question that contains a paradigmatic example, when you would not slap on a check-my-work tag, or a do-this-calculation tag either. (p.s. Full disclosure: As far as I understand the creation of a tag is permitted for users of reputation 1000 or larger.) Jul 18 '14 at 5:06
• +1, definitely agree. But as far as being unable to summarize this further, surely you could. For starters, you could eliminate the asides, which don't actually add much to your question summary anyway. That would go far to making this post less.... disjointed (yeah, that feels like a close enough descriptor)
– Jim
Jul 18 '14 at 14:02
• I'm not entirely convinced that this should be on topic; I think that this would fall under the category of insufficient prior research because the "standard" terminology should be found in the introductory textbook of that sub-field (and more "technical" terms found in literature or advanced textbooks). Jul 18 '14 at 14:42
• @KyleKanos Good point. In terms of the homework reason, I think it is on topic, but in terms of prior research reason, majority of cases might be off topic. But given that this entire thread is dedicated to the homework reason, I would be hesitant to say we should mark this as off topic. That would encourage people to use the homework reason to mark these questions as off topic, which, as I said, I don't believe is valid
– Jim
Jul 18 '14 at 15:58
• @Kyle Kanos: "this would fall under the category of insufficient prior research" -- For example, consider this question: "$\Delta^+$ decay in GZK process"; (PSE/q/113252). It does actually boil down to solving a problem which is discussed in lectures and/or given as a homework problem (which surely is manageable, once you've attended the lecture). The calculation turns up in (numerous) textbooks which are (justly called) "introductory". Closing/erasing such a question accomplishes: what? Jul 18 '14 at 21:09
• @user12262: your example and the above post are different questions. Surely understanding branching ratios is and important topic & ought to be covered here. Technical & non-technical jargon, in my opinion, should not be on-topic here. Jul 18 '14 at 23:16

Questions that can be summarized as "Please explicitly derive this equation/law for me" are OFF topic.

• Woah woah woah, are you saying that unlike math SE, we don't allow proofs here?
– Nick
Jul 26 '14 at 11:07
• @Nick no, if a proof is supplemental to an informative answer, it is very welcome. But let me be clear that we are not Math.SE. One can understand the need for posts on Math.SE to be allowed to have detailed mathematical derivations. It is there raison d'etre. Here we tend to focus on the concepts of physics. Explicit derivations are often given even on wikipedia already. This also springs from the tendency of homework questions to be "Show how you can use this starting point to derive this equation/law". Something straight from their textbook that they hope to be given the answer for
– Jim
Jul 28 '14 at 13:37
• In this case I think a lot depends on how much prior research has been done. If a derivation is available in standard resources, we should expect the OP to have checked them, and ask about a step in that derivation. But sometimes derivations are hard to find, and in those cases I think it's fair to ask for one directly (or at least an outline of the strategy). Jul 29 '14 at 15:52
• ^ agree. There is no single, short, cover-all statement for this. Assessments need to be made on a case-by-case basis sometimes.
– Jim
Jul 29 '14 at 15:55

The phrase "ask about a specific physics concept" is ambiguous in meaning, and is not being correctly understood by the majority of homework posters.

• I mostly agree with the comment on it not being correctly understood by many homework posters. I wonder if part of this is a language barrier and possible translations/interpretations of the word "concept". Can we clarify this with one or a few clear examples and counterexamples? Jul 29 '14 at 0:05
• I personally think the phrase is not ambiguous, but it certainly is not always correctly understood by homework posters (meaning I'm probably wrong about the ambiguity). As it is, HW posters seem to think throwing the words "physics concept" changes the question to on-topic. So I think that whatever the wording, the same will be true
– Jim
Aug 1 '14 at 13:43
• a "core/fundamental physics concept" might be clearer. Aug 4 '14 at 20:03

Questions that can be summarized as "here a problem and my solution with my reasoning for each step, where has my reasoning gone wrong?" are ON topic.

• I'm rather split on this one. On the one hand, I believe we should not do "Check my work" questions. On the other hand, from picking apart a reasoning gone wrong (that actually shows an effort to tackle the problem), true conceptual clarification might arise in the answers, but since the person asking the question (questioner? questionee?) does not know the concept they are missing, they cannot ask for it.
– ACuriousMind Mod
Jul 15 '14 at 0:20
• IMO, this isn't terribly different from the "Check my work" question. However, this particular type of question could become a good question if the "steps" part is eliminated so that the question is, "I was doing <X> and didn't understand why <Y> isn't the case. Can someone elaborate" Jul 15 '14 at 2:34
• I put both up since I see them as different (though I'm not sure either is on topic). Jul 15 '14 at 2:53
• I agree these questions have the potential to be on topic. But we have to make sure the question is useful to the broader community too. If it is a "where has my reasoning gone wrong in solving problem 13.2 from this text?" question, it is arguably too specific to be on topic
– Jim
Jul 15 '14 at 12:52
• I think this is a grey zone where the decisive factors for on or off topic are difficult to pin down in general and especially the quality (and to a lesser extent quantity) of the effort can tip the scales. The generality (that's a word, right?) of the problem also plays an important role, as Jim points out. I will therefore vote neither up nor down on this one. Jul 29 '14 at 0:13

Here at Physics.SE, we prefer questions that are interesting. Questions about homework that indicate the asker finds the question uninteresting ("please solve this problem, I have no idea how"; "please check my work, I have no idea whether it's right") will probably be closed. Questions which demonstrate why the asker finds the question interesting ("I tried X, expecting to find Y, but instead found Z and am stuck") are more likely to arouse the interest of the community and get good answers.

• Interesting is subjective, so I am not sure how we can glean anything objective from it. Jul 16 '14 at 0:10
• @KyleKanos That's intentional. All moderation decisions involve some degree of subjectivity. I think it's better to be honest about that than to pretend that there exists a set of objective rules for asking good questions. I also see nothing wrong with encouraging people to lurk a little while if they want to understand what sorts of questions are well-received here, rather than offering a list of putative rules.
– rob Mod
Jul 16 '14 at 3:18
• Also, this seems to be a lot longer than the short statement that Kyle requested and contains several elements found in other posts. Jul 16 '14 at 10:32
• Might this better be worded along the lines of "we expect some prior effort/research/thought before posting a question"? Doing any/all of those demonstrates "interest" on the part of the asker, make an answer more likely, and are less subject to interpretation (though not completely, of course). Jul 16 '14 at 16:46
• The core of this statement - "we like questions which require effort, and we like that you have exerted effort" I very much agree with. I don't like the addition of "interesting", for the aforementioned subjectivity problems. Jul 24 '14 at 0:22
• You can see I'm a “newbie” here myself, but I wonder what is wrong with pointing to “interesting” questions. I come to this site for ideas that are interesting to me, and I will be prepared to think about an answer if I find a question interesting, not if it adheres to a policy. That this is subjective is only natural. Jul 24 '14 at 12:46

The close reason as stated does not emphasize that we do not answer "check my work" questions enough.

"Homework-like questions should ask about a specific physics concept and show some effort to work through the problem. We want our questions to be useful to the broader community, and to future users. See our meta site for more guidance on how to edit your question to make it better"

• I agree that this could be better clarified, but I think the place to do it is in the meta post on the homework policy, not in the close reason itself. (This is exactly the reason that ask about a specific physics concept is bolded.) Jul 15 '14 at 1:30
• Ah that close reason - so many person hours went into crafting it, where we tried to convey the most important points succinctly enough to actually be read. I'm not saying it can't be improved, but I remember running into tradeoffs between corner-case completeness vs. emphasis and clarity for common cases.
– user10851
Jul 15 '14 at 2:34
• @DavidZ My problem with it is that it says "show your work" (to paraphrase part of it), but if you follow that blindly without reading the meta post it doesn't help, which I've noticed has come up as a point of confusion/frustration once or twice. Jul 15 '14 at 2:59
• @Kyle it says "ask about a specific physics concept and show your work." Of course if you follow half of the stated close reason blindly, it won't help. If you follow both parts, then the question should be reasonably close to okay. Jul 15 '14 at 3:24
• @DavidZ I'm not entirely convinced. "My question asks specifically about the angular momentum of this pendulum and why I don't get 4.3325s for the period." Maybe I'm exaggerating a bit or imagining things, my impression is that the most frequent edit to homework questions I see in the re-open queue is a work through of the problem added, and "sorry I didn't show my work before, where is my mistake?" Jul 15 '14 at 4:21
• @Kyle I think I'm in agreement with you. The "show your work part" seems to encourage people to post "please check my work" type questions. We (rightly in my opinion) close tons of homework questions that have work. Jul 15 '14 at 5:36
• Perhaps we should bold, underline, italicize, and put between exclamation marks the "and"? It is a logical and. Homework question about a specific physics concept are just as off topic without showing work as those that show work without being about a specific concept.
– Jim
Jul 15 '14 at 12:50
• @Kyle (3 comments up) I think those askers get hung up on the "show your work" requirement and ignore the other one. Probably because most physics sites have some similar requirement about showing your work for a homework problem, so askers know to expect it. The "ask about a specific physics concept" requirement is unique to us, AFAIK. Jul 15 '14 at 20:08
• @Jim yeah, or color it red, or make a two-item bulleted list... any of various ways to improve the visibility. But I think no matter how we phrase/format the close reason, a lot of people just will not read it properly. I think the only foolproof way to get them to pay attention to both requirements is to prevent them from getting any help (i.e. keep the question on hold) until both requirements are satisfied. Jul 15 '14 at 20:10
• Really the issue is we have 3 requirements: (1) conceptual, (2) show what you did, and (3) we don't check your work. In theory (3) is subsumed by (1), but it's a bit of a leap, which is why we moved (3) from an obscure location in the meta post to the block at the top. Still, it only explicitly appears there.
– user10851
Jul 16 '14 at 19:12

Questions that can be summarized as "please check my work" are OFF topic.

• Now that's debatable, especially if OP explicitly shows what he has done and is only asking ''where am I committing a mistake?''. That doesn't violate the existing homework policy, or does it? Jul 15 '14 at 9:28
• @New_new_newbie In the past, that kind of question has usually been considered off-topic. However, the purpose of voting here is to determine is it truly does violate our collaborative homework policy
– Jim
Jul 15 '14 at 12:45
• @New_new_newbie as Jim says, if you agree, vote up, if not, vote down :) Jul 15 '14 at 15:59
• Right, we are not the free tutors of these students, they probably have someone else correcting already their homework or some teacher to help them.
– Rol
Jul 22 '15 at 7:52