What's the purpose of "This page is intentionally left blank" we see in books?
What's the purpose of "This page is intentionally left blank" we see in books? Why not just leave the page blank and write nothing on it?
I'm voting to close this question as off-topic because it has nothing to do with UX but is a question about the history of book printing.
@VitalyMijiritsky A blank page could have a very specific intention. We use white spaces all the time on screens. Besides, UX is not just digital.
@VitalyMijiritsky I was almost completely convinced of what you're saying, but on DasBeasto's answer, Nathan Rabe made the comment, "It relates to UX in the same way we say '0 search results found' instead of just leaving the page blank." This may be a grey area.
I think this meta question pretty accurately sums up your doubt of the relevance of the question, and I for one agree with the top answer for it.
@AlanGeorge et al.: Yes, every manufactured object in the world has "a user" and the user has "experiences". So most questions about why the man-made world looks like it does could be made about UX or at least about design. And I've asked and answered my share of "real-world questions" on this site. But we do have to draw the line somewhere. I personally think that this one has crossed that line. Others may disagree - that's precisely what voting is for.
A *paradoxically* printed page in a book stating that itself is left blank on purpose is a little more on the UX side than *"every manufactured object in the world has a user..."*, but that's my 2 cents.
While the reason for this isn't UX, I consider it a fair question as it isn't clear that there isn't a UX reason for it unless you already know the answer.
Related anecdote: At school around 1980 (i.e. long before double-sided photocopiers), our chemistry teacher wanted (say) 30 copies of a previous exam paper for the class to practise on. It was one sheet, with questions on one side and something like "_This page left blank for rough working_" on the reverse. Back came 30 copies of the page with questions (totally blank on the reverse) and 30 copies of "_This page..._" (also blank on the reverse)!
The purpose is to locate those people who say, "No it's not, it's got this writing on it, so it's no longer blank!"
@Michael: I once compiled a document on the Z80 instruction set which had a few "_This page intentionally left otherwise blank_" pages in it.
I think this question is acceptable, but it is thoroughly lacking in any signs of prior research.
What's the purpose of splash screens, hourglass pointers, and other indicators of delayed responsivity?
Should this question be migrated to Graphic Design SE? One of the bullet points explicitly says "Layout and printing."
This wikipedia page sums it up quite nicely https://en.wikipedia.org/wiki/Intentionally_blank_page
Such pages may serve purposes ranging from place-holding to space-filling and content separation.
And the reason I see it most often
Intentionally blank pages are usually the result of printing conventions and techniques.... Book pages are often printed on large sheets because of technical and financial considerations. Thus, a group of 8, 16, or 32 consecutive pages will be printed on a single sheet in such a way that when the sheet is mechanically folded and cut, the pages will be in the correct order for binding.
And to add to why they write "This page is intentionally left blank" instead of just leaving it blank
They are marked "intentionally left blank", of course, because they don't want readers to worry that a printing mistake has left them missing something good. http://www.quora.com/Why-do-books-sometimes-have-pages-marked-This-page-intentionally-left-blank
So this is a *side effect* of technical/financial issues and has nothing to do with the end *user experience*?
As far as I can tell the actual blank page is to account for technical issues/convenience but the phrase "This page is intentionally left blank" itself is for the user to not get confused about the blank page.
It relates to UX in the same way we say "0 search results found" instead of just leaving the page blank.
@NathanRabe I disagree. I doubt any readers will sit there staring at the blank page of a book, waiting for it load some content, if it doesn't say "This page is intentionally left blank."
@Brian: No, they won't keep staring at the page. But they might feel annoyed that they've been sold a defective product, and contact the bookseller/printer and complain. Or (in an examination context) they may panic and believe their exam paper is missing some questions, forcing them to speak to the invigilator/proctor and disrupt the concentration of other examinees (this is the context I've most often encountered "intentionally left blank"!)
@psmears Those are all true. Your comment would actually make a good answer to the question. My point is that "0 search results found" shows a user that their action has been processed, and provides the result of their action (in this case, a search). "This page is intentionally left blank" is not a response to an action in any way, and is there to let the reader know that it being blank is not a mistake. The two phrases are in in no way the same, aside from that omitting each would leave a blank page.
Brian, the two are exactly the same. You're saying "they are in no way the same except that they both have the exact same reason for their entire existence". Your "0 results is a response, but intentionally left blank isn't a response" doesn't hold weight: both are a response to an action. I can change the response in my book by supplying different parameters (flipping to a different page) just like I can get a different response in my search engine with different parameters (search a term that exists).
I once found 5 consecutive missing pages in the last chapter of a really good novel. I now scan books for blank pages before I read them. These notices help a lot.
It seems like it's more for the benefit of the user of the raw prints (i.e. the person assembling the book) than the end user of the content of the book.
@justhalf yes the last quote is sufficient to answer the given question, but without the context that the rest of the answer provides people would ask why the page is there in the first place. So I just included everything for completeness.
@DasBeasto Yes, I agree that it is good to include the context. But the way I see the question is that I expect your last quote to appear first. That is, I see the question as having blank pages as assumed, and asking why the text is written there. So if I were to answer this question, I will put that last quote first, and give the reason why blank pages exist in the first place afterwards, instead of putting the last quote after "and to add why", which seems to suggest that the previous parts were the main answer. But OP had accepted your answer anyway, so, I think this is fine =)
@Krumia: There's an implicit _"aside from this disclaimer"_. Get over it! :P
I don't see why the bit about printing on large sheets and cutting them up has anything to do with it. Whether you print pages 1 sheet at a time on your desktop printer, or 16 pages per sheet on a big offset press, the final book should look the same. Either way, you might have blank sheets between sections or chapters if you want new chapters to always start on an odd-numbered page. Most often, I think, the issue comes up with book published in binders where updates are published as insert pages rather than a whole new book.
@Krumia: Thirty years ago, when I started on System III Unix, these pages were labelled "This page is intentionally left almost blank".
Consider a high stress situation where the content of the book matters, such as a SAT test booklet. An unexpectedly blank page could have a noticeable emotional effect on the test taker, forcing them to rapidly flip back and forth to make **sure** there was no missing content.