Re: Accessibility questions that are less technical
David Carlisle <[email protected]> Tue, 27 Jan 2026 14:44:39 +0000
| Newsgroups | gmane.comp.tex.texhax |
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| Message-ID | <CAEW6iOiZVEyUqOsKY=NsEL-UvmXpdM8B4mQua5c7XUCZUOu+=Q@mail.gmail.com> |
--0000000000007e4c6606495faa21 Content-Type: text/plain; charset="UTF-8" On Tue, 27 Jan 2026 at 13:36, Jim Hefferon <[email protected]> wrote: > Hello. I have a number of questions that are perhaps less technical > than most posts here. I apologize; they seem too soft SE or latex3's > GitHub list, the tug.org accessibility list does not have substantive > traffic, and the blind-mathematicians mailing list did not accept my > email. I hope folks here don't mind. > > I intend to re-make a book of mine to be accessible and I'm struggling > with some things that arose out of some preliminary, practice, work > that I did. > > 1) At the bottom is an MWE document (I have today's TeX Live and I'm > using LuaLaTeX). I do not currently have access to Windows so the > NVDA screen reader is not an option. On Linux, Okular does not read > the math correctly You might do better to target pdf 1.7 and UA-1 rather than UA-2 or at least if using UA-2 add an Alt to the Formula (which is the default with UA-1) by adding tagging-setup={ math/alt/use,math/setup=mathml-SE} alt/use specifies that LaTeX should add an Alt property to every Formula (with the TeX source of that expression) this is not as good as tagging with mathml, but better than nothing. Note however that what matters most is the screen readers used by your (human) not the one you have access to, so that may be nvda or jaws on windows. You could try orca with firefox 148 or higher (currently in beta) which has support for tagged pdf, although I haven't had great success with orca so far. > and does not read the alt text or "Black bird." at > all. Are there better screen reader options? I'd sure like to do the > highest PDF standard. At the moment I am developing my docs without > being able to know what is the outcome and it is awkward. I can recommend using ngpdf https://ngpdf.com/loadFile to test your file, that will show the tag structure and also the derived HTML file, which is a reasonable representation of the accessible view of the document. > (I have > not tried converting to HTML and using an HTML reader. I hope to post > the PDF for free download.) > > 2) Can alt text contain math? If not, I must write "x times y" and > "the sine function"? > As noted above latex will add the tex source as alt text if you specify pdf 1.7 and UA-1 or if you explicitly set math/alt/use key to true. > > 3) Is there any way to influence screen readers outside of textual? > To give a concrete example, I would like to get a pause after > execution of ltx-talk's \frametitle{..} command. if the title is marked up as a title you would hope the screen reader announces it as such and adds a suitable pause. > I see that the > package's documentation recommends periods in the title but in the the > typographic tradition that I am used to, headlines don't have periods. > Is this just a matter of hoping that screen readers improve over time? > Check the tagging of the title, if it is tagged as a heading it ought to be automatically set off from the following text. > > 4) Is there some best practices document that folks could recommend? > For example, googling for guidelines on writing alt text gives many > results but even the most high-profile ones seem to me to be both > vague and contradictory. vague and contradictory unfortunately describes many of the documents in this area both the standards themselves and tutorials from various places. Things are getting better though. For instance, some advocate a character > limit while others recommend extensive description. I confess that I > find it impossible to briefly describe a mathematical graph of the > area under f(x)=sin(x) between x=a and x=b broken into ten Reimann > boxes, particularly without mathematical symbols. well exactly. You can use unicode math symbols in an alt text but not math layout but mostly what you lose is navigation. You can't really follow a full math display in a "one take" reading of an alt text whatever text you place in the attribute. Using mathml allows the reader to navigate into the expression, reading subterms at their pace and in their order. But of course if you are using a screen reader that doesn't understand the tagging that's just a theoretical benefit, and using Alt is all you have. > In general, the > advice I have seen online seems more directed to business documents > than to documents for math or science. > that and often assuming that the tagging is being done by hand by remediating the document after production rather than being added as part of the typesetting as in LaTeX > > 5) There is sometimes a tradeoff between what is useful for > visually-impaired users and others. To again name a concrete example > from ltx-talk, I sometimes show a sequence of graphics as slides > inside of a frame to illustrate changes (say, developing the arc > length as a limit by showing line segments become shorter). Only the > graphic changes, not the surrounding text. I understand screen > readers to re-read the entire slide; certainly Okular does. That sounds wrong, the default behaviour is just to read the last slide (which is what you want for gradual reveals) If you have more complicated interactions with text coming and going it has some possibility to control which text gets marked to be read and which is marked as Artifact. That's > pretty tedious after five slides. Does anyone have advice about > working through that? > It's not supposed to happen. > > Thank you, > Jim Hefferon > > ................ Example document ............. > A video of your document unchanged being read by nvda (from foxit) is at https://www.dropbox.com/scl/fi/wbyumxcv16wk8vozlox9f/jh1.mp4?rlkey=qrmmrykcdv964zyvrpakvsy3m&st=0igpgs0v&dl=0 > > \DocumentMetadata{ > lang = en, > pdfstandard = ua-2, > pdfstandard = a-4f, %or a-4 > tagging=on, > tagging-setup={math/setup=mathml-SE} > } > \documentclass{article} > \usepackage{unicode-math} > \usepackage{graphicx} > \usepackage{mathtools} > > \begin{document} > Red dog. > \begin{equation*} > \int_{x=0}^1 x^2\,dx=\pi > \end{equation*} > Blue fish. > \begin{center} > % \includegraphics[alt={Show the integral $\int x^2 dx$ as a > graph.}]{example-image-a} > \includegraphics[alt={Show the integral as a graph.}]{example-image-a} > \end{center} > Black bird. > \end{document} > > -- > "Does not the Captain seek your advice sir?" > "Not always," said Stephen. > --0000000000007e4c6606495faa21 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr"><div dir=3D"ltr"><div dir=3D"ltr"><br></div><br><div class= =3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Tue, 27 Jan 2026 = at 13:36, Jim Hefferon <<a href=3D"mailto:[email protected]" target= =3D"_blank">[email protected]</a>> wrote:<br></div><blockquote clas= s=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid r= gb(204,204,204);padding-left:1ex">Hello.=C2=A0 I have a number of questions= that are perhaps less technical<br> than most posts here.=C2=A0 I apologize; they seem too soft SE or latex3= 9;s<br> GitHub list, the <a href=3D"http://tug.org" rel=3D"noreferrer" target=3D"_b= lank">tug.org</a> accessibility list does not have substantive<br> traffic, and the blind-mathematicians mailing list did not accept my<br> email. I hope folks here don't mind.<br> <br> I intend to re-make a book of mine to be accessible and I'm struggling<= br> with some things that arose out of some preliminary, practice, work<br> that I did.<br> <br> 1) At the bottom is an MWE document (I have today's TeX Live and I'= m<br> using LuaLaTeX).=C2=A0 I do not currently have access to Windows so the<br> NVDA screen reader is not an option.=C2=A0 On Linux, Okular does not read<b= r> the math correctly</blockquote><div><br></div><div>You might do better to t= arget pdf 1.7 and UA-1 rather than UA-2</div><div>or at least if using UA-2= add an Alt to the Formula (which is the default</div><div>with UA-1) by ad= ding=C2=A0</div><div><br></div><div>tagging-setup=3D{ math/alt/use,math/set= up=3Dmathml-SE}=C2=A0</div><div><br></div><div>alt/use specifies that LaTeX= should add=C2=A0an Alt property to every Formula (with=C2=A0the TeX source= of that expression)</div><div><br></div><div>this is not as good as taggin= g with mathml, but better than nothing.</div><div><br></div><div>Note howev= er that what matters most is the screen readers used by your (human) not th= e one you have access to, so that may be nvda or jaws on windows.</div><div= ><br></div><div>You could try orca with=C2=A0 firefox 148 or higher (curren= tly in beta) which has support for tagged pdf, although</div><div>I haven&#= 39;t had great success with orca so far.</div><div><br></div><div><br></div= ><div>=C2=A0</div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px= 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> and do= es not read the alt text or "Black bird." at<br> all.=C2=A0 Are there better screen reader options?=C2=A0 I'd sure like = to do the<br> highest PDF standard.=C2=A0 At the moment I am developing my docs without<b= r> being able to know what is the outcome and it is awkward.</blockquote><div>= <br></div><div><br></div><div>I can recommend using ngpdf=C2=A0=C2=A0<a hre= f=3D"https://ngpdf.com/loadFile" target=3D"_blank">https://ngpdf.com/loadFi= le</a> to test your file, that will show the tag structure</div><div>and al= so the derived HTML file, which is a reasonable representation of the acces= sible view of the document.</div><div><br></div><div>=C2=A0</div><blockquot= e class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px s= olid rgb(204,204,204);padding-left:1ex"> =C2=A0(I have<br> not tried converting to HTML and using an HTML reader.=C2=A0 I hope to post= <br> the PDF for free download.)<br> <br> 2) Can alt text contain math?=C2=A0 If not, I must write "x times y&qu= ot; and<br> "the sine function"?<br></blockquote><div><br></div><div><br></di= v><div>As noted above latex will add the tex=C2=A0source as alt text if you= specify pdf 1.7 and UA-1 or if you explicitly=C2=A0set</div><div>math/alt/= use key to true.</div><div><br></div><div>=C2=A0</div><blockquote class=3D"= gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(20= 4,204,204);padding-left:1ex"> <br> 3) Is there any way to influence screen readers outside of textual?<br> To give a concrete example, I would like to get a pause after<br> execution of ltx-talk's \frametitle{..} command.</blockquote><div><br><= /div><div>if the title is marked up as a title you would hope the screen re= ader announces it as such and adds a suitable pause.</div><div><br></div><d= iv>=C2=A0</div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0p= x 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">=C2=A0 I s= ee that the<br> package's documentation recommends periods in the title but in the the<= br> typographic tradition that I am used to, headlines don't have periods.<= br> Is this just a matter of hoping that screen readers improve over time?<br><= /blockquote><div><br></div><div>Check the tagging of the title, if it is ta= gged as a heading it ought to be automatically set off from the following t= ext.</div><div>=C2=A0</div><blockquote class=3D"gmail_quote" style=3D"margi= n:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex= "> <br> 4) Is there some best practices document that folks could recommend?<br> For example, googling for guidelines on writing alt text gives many<br> results but even the most high-profile ones seem to me to be both<br> vague and contradictory.=C2=A0</blockquote><div><br></div><div>vague and co= ntradictory unfortunately describes many of the documents in this area=C2= =A0</div><div>both the standards themselves and tutorials from various plac= es. Things are getting better though.</div><div><br></div><blockquote class= =3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rg= b(204,204,204);padding-left:1ex"> For instance, some advocate a character<b= r> limit while others recommend extensive description. I confess that I<br> find it impossible to briefly describe a mathematical graph of the<br> area under f(x)=3Dsin(x) between x=3Da and x=3Db broken into ten Reimann<br= > boxes, particularly without mathematical symbols.=C2=A0</blockquote><div><b= r></div><div>well exactly. You can use unicode math symbols in an alt text = but not math layout</div><div>but mostly what you lose is navigation. You c= an't really follow a full math display</div><div>in a "one take&qu= ot; reading of an alt text whatever text you place in the attribute.=C2=A0<= /div><div>Using mathml allows the reader to navigate into the expression,</= div><div>reading subterms at their pace and in their order. But of course i= f you are using a screen reader that doesn't understand the tagging tha= t's just a theoretical benefit, and using Alt is all you have.</div><di= v>=C2=A0</div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px= 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> In general= , the<br> advice I have seen online seems more directed to business documents<br> than to documents for math or science.<br></blockquote><div><br></div><div>= that and often assuming that the tagging is being done by hand by remediati= ng the document after production rather than being added as part of the=C2= =A0typesetting as in LaTeX=C2=A0</div><blockquote class=3D"gmail_quote" sty= le=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);paddi= ng-left:1ex"> <br> 5) There is sometimes a tradeoff between what is useful for<br> visually-impaired users and others.=C2=A0 To again name a concrete example<= br> from ltx-talk, I sometimes show a sequence of graphics as slides<br> inside of a frame to illustrate changes (say, developing the arc<br> length as a limit by showing line segments become shorter).=C2=A0 Only the<= br> graphic changes, not the surrounding text.=C2=A0 I understand screen<br> readers to re-read the entire slide; certainly Okular does.=C2=A0</blockquo= te><div><br></div><div>That sounds wrong, the default behaviour is just to = read the last slide (which is what you want for gradual reveals)</div><div>= If you have more complicated interactions with text coming and going it has= some=C2=A0 possibility=C2=A0to control which text</div><div>gets marked to= be read and which is marked as Artifact.</div><div><br></div><blockquote c= lass=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px soli= d rgb(204,204,204);padding-left:1ex"> That's<br> pretty tedious after five slides.=C2=A0 Does anyone have advice about<br> working through that?<br></blockquote><div><br></div><div>It's not supp= osed to happen.</div><div>=C2=A0</div><blockquote class=3D"gmail_quote" sty= le=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);paddi= ng-left:1ex"> <br> Thank you,<br> Jim Hefferon<br> <br> ................ Example document .............<br></blockquote><div><br></= div><div>A video of your document unchanged being read by nvda (from foxit)= is at</div><div><br></div><div><a href=3D"https://www.dropbox.com/scl/fi/w= byumxcv16wk8vozlox9f/jh1.mp4?rlkey=3Dqrmmrykcdv964zyvrpakvsy3m&st=3D0ig= pgs0v&dl=3D0">https://www.dropbox.com/scl/fi/wbyumxcv16wk8vozlox9f/jh1.= mp4?rlkey=3Dqrmmrykcdv964zyvrpakvsy3m&st=3D0igpgs0v&dl=3D0</a></div= ><div><br></div><div>=C2=A0</div><blockquote class=3D"gmail_quote" style=3D= "margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-le= ft:1ex"> <br> \DocumentMetadata{<br> =C2=A0 lang=C2=A0 =C2=A0 =C2=A0 =C2=A0 =3D en,<br> =C2=A0 pdfstandard =3D ua-2,<br> =C2=A0 pdfstandard =3D a-4f, %or a-4<br> =C2=A0 tagging=3Don,<br> =C2=A0 tagging-setup=3D{math/setup=3Dmathml-SE}<br> }<br> \documentclass{article}<br> \usepackage{unicode-math}<br> \usepackage{graphicx}<br> \usepackage{mathtools}<br> <br> \begin{document}<br> Red dog.<br> \begin{equation*}<br> =C2=A0 \int_{x=3D0}^1 x^2\,dx=3D\pi<br> \end{equation*}<br> Blue fish.<br> \begin{center}<br> =C2=A0 % \includegraphics[alt=3D{Show the integral $\int x^2 dx$ as a<br> graph.}]{example-image-a}<br> =C2=A0 \includegraphics[alt=3D{Show the integral as a graph.}]{example-imag= e-a}<br> \end{center}<br> Black bird.<br> \end{document}<br> <br> -- <br> "Does not the Captain seek your advice sir?"<br> "Not always," said Stephen.<br> </blockquote></div></div> </div> --0000000000007e4c6606495faa21--