# Are pictures of hand-written drawings allowed?

My question, is whether uploading a picture of some hand-written drawings (not text I could write in TeX), might be acceptable, such as the one below.

Sometimes I just have an easier time explaining things when I have a picture available This drawing, for example, was to help me (and maybe others) see a combinatorial argument for the identity

$$\binom{n}{0}^2 + \binom{n}{1}^2 + \binom{n}{2}^{2} \dots \binom{n}{n}^{2}= \binom{2n}{n}$$

• Well if you have a look at the images which are used in MSE posts, certainly many of them are done by hand. – Martin Sleziak Dec 31 '13 at 10:08
• @MartinSleziak, really, then I'll look harder. – NaN Dec 31 '13 at 10:21
• @IDentity I confirm, they are allowed. – user93957 Dec 31 '13 at 10:36
• Drawings are OK to augment a post, but please use as much text as possible (including $\TeX$ for notation) to make your post searchable and easier to read. – Ayman Hourieh Dec 31 '13 at 11:09
• Looks better than my PAINT work... – draks ... Dec 31 '13 at 14:39
• +1 to @AymanHourieh's comment for searchability. – becko Jan 9 '14 at 22:55

Yes, I think it's perfectly acceptable to use a hand-drawn picture to supplement a post - especially when the picture is used to illustrate or clarify something that's written in text or Latex.

In order to keep the post searchable, it's best to include plenty of text explaining why the picture is useful; so simply avoid a picture-only post and it should be quite fine.

• Bad qualities to avoid in such pictures: sloppiness that makes it unreadable, giant margins of useless whitespace, being enormous... the one you posted, IDentity, looks great though! – rschwieb Dec 31 '13 at 17:51
• I have at times deliberately posted hand-drawn diagrams, in an attempt to emphasize the meta-point that even shaky hand drawings are better than attempts to describe the situation in prose when the situation needs a diagram. Unfortunately it's a bit self-defeating for me since I don't have a scanner, and cleaning up a digital photo to an acceptable quality (I'm willing to expose my shaky lines to general ridicule, but not bad scans!) often takes longer that it would to recreate the diagram digitally from scratch ... – Henning Makholm Jan 1 '14 at 2:42
• Another important reason to include descriptive text is accessibility for the blind/vision-impaired. – Alex Becker Jan 1 '14 at 5:59
• @HenningMakholm, take a look at this question which may help. I didn't use an iPad or paper for this drawing. I used a Samsung Galaxy Note 10.1, which has plenty of usability issues, but one thing it does decently is take handwriting, draw straight lines, and export to PDF. – NaN Jan 3 '14 at 0:55
• @IDentity: I'm not going to go out and buy additional hardware specifically for posting diagrams to MSE once every several months. – Henning Makholm Jan 4 '14 at 14:38
• Of course. Making hand-drawn pictures is much faster than using software, for most people, and if the picture's neat and readable, what's the problem? We're not talking about figures to include in a journal article. – Stefan Smith Jan 8 '14 at 4:07

Consider using AMSCD for drawings if you know how (I don't) or can learn (I will). Remember that the text in square brackets should be as detailed a description of the picture as you can reasonably make it for the benefit of blind people. That field will become the alt text. For example,

should have a useful alt text. The way you wrote it, someone using a text-only browser, Braille display, etc., will see only "enter image description here", which is not exactly helpful.

• I added the alt text now. I also removed the top-left "show $\binom{n}{k}\binom{k}{a} \dots$". I don't know why I wrote that there, since I was trying to prove something else. – NaN Jan 3 '14 at 0:52
• @IDentity, I don't think you understand the purpose of alt text. Alt text is not a caption for a picture (that is what the HTML title attribute is for). Rather, alt text is what is shown when the picture is not. If at all possible, it should stand on its own. If not, it should at least give the reader a sense of what all the fuss is about. There is certainly no reason to run all the words together in it. Please click the edit button on my answer to view the source so you can see the sort of description I mean (or view the img element properties, or view the page in lynx/links). – dfeuer Jan 3 '14 at 5:05
• it appears the edit button is disabled for me. I guess there's a minimum reputation to edit others' answers. Still, your comment makes sense and other uses of alt text may be, for example, a message which informs the user that they do not have JavaScript running or flash installed. – NaN Jan 3 '14 at 8:59
• @Identity, Those are other inappropriate uses, yes. For appropriate ones, see for example the webcomic Daywood Academy by the late Julia "Eclipse" Orth. – dfeuer Jan 3 '14 at 13:48

Here is an example that went well, Inscribing a rhombus within a convex quadrilateral

I described a compass and straightedge construction in words, and someone in SE posted a step by step illustration, I think using Geogebra.. Not long after, I bought a very simple one-page scanner, and was able to post color jpegs of my original drawings as a separate answer.

With that in mind, I think actual mathematics symbols should be put in Latex. I dislike it when someone posts a jpeg of homework questions. Shows a number of negative things, including lack of respect for us.