DocOnce has good support for creating slides. Especially if you have ordinary DocOnce documents with running text, it is an efficient process to strip down this text to a slide format.
Rather than speaking about slides, we think of study guides where the material is presented in a very condensed, effective, summarizing form for overview, use in lectures, and repetition. The slide format is a good way of writing study guides, but by explicitly thinking of study guides the slide format can be made more effective for self-study when overview and repetition are necessary - with a particular emphasis on gaining understanding.
It is a very challenging balance between enough information for self-study by reading slides and the modest amount of information you want in slides for oral presentations. For a talk, you will have (very) little text on slides and rely on figures. This is not so effective in a teaching and study guide setting. Some text is indeed necessary, but it has to be minimized. Michael Alley's evidence-assertion slide design is effective: summarize the slide's key point in a heading over 1-2 lines, use figures/equations/code effectively, and work on minimizing text.
Make it an assumption that the reader of a study guide is also a reader of the underlying running text in the chapter.
For each DoOnce file in the chapter ch2 it can be wise to make a
corresponding study guide file in the subdirectory slides-ch2.
For example, part1.do.txt has its counterpart with slides in
slides-ch2/part1.do.txt. Then there is a file slides_ch2.do.txt
which assembles the parts if slides-ch2, typically with a content
like
TITLE: Study Guide: Some title
AUTHOR: Author Name Email:somename@someplace.net at Institute One
DATE: today
# #ifdef WITH_TOC
!split
TOC: on
# #endif
# #include "lec-ch2/part1.do.txt"
# #include "lec-ch2/part2.do.txt"
# #include "lec-ch2/part3.do.txt"
The author has the following work flow for generating slides for a
chapter file, say part1.do.txt.
part1.do.txt to slides-ch2/part1.do.txt.slides_ch2.do.txt and include slides-ch2/part1.do.txt.ch2.do.txt file, but sometimes it can
   be more natural to have larger parts than sections in the slide
   collection.=, while
   each slide has a DocOnce subsection heading with 5 =.slides-ch2/part1.do.txt:!split right above every slide heading!--denumber_all_equations, or
     you can edit the LaTeX math environment manually.
     Remember that
     references to equations numbers must be removed from the slides too!FORMAT and
     writing MOVIE for HTML output and just a link in PDF output
     might be necessary. See the manual for how to work with movies in DocOnce.
You want students to study the slides/study guide before a lecture.
To measure to what extent this is done, you can insert multiple-choice
questions about the most basic concepts in the slides (using the DocOnce
quiz environment). With quiztools you can extract all such
multiple-choice questions, create online games with Kahoot, and
let the students answer with their smart phones at the beginning of
a lecture.
The scores are visible to all on the main screen and communicate the
preparation level.
I would add a fourth requirement to the list in the previous
section: a study guide should also be available
as an IPython/Jupyter notebook for experimentation, extension, and
personal notes. This is technically
straightforward by just generating a notebook from the slide source,
but a notebook puts some constraints
on code snippets and figures such that it is meaningful to execute
all the code. Moreover, many figures are inlined and appear as a result of
executing code in a notebook. While other formats will show a code
snippet and then the corresponding figure, the notebook can leave
the figure out and let it appear as the code cell is executed.
Technically in DocOnce, this is solved by putting a FIGURE construction
inside an # #if FORMAT test (or % if FORMAT if Mako branches are
preferred). If `FORMAT != 'ipynb``, you have a FIGURE line, otherwise
the preceding code cell is supposed to generate the figure.
The book's running text can also be converted to a notebook. However, the notebook then consists of very much text and often a lot of cross-referencing because this is the typically writing style of a book chapter. This style is not so effective for a notebook. Stripped text with focus on formulas, code, and figures is more ideal for a notebook and this is the style of a study guide realized by slides.
There is a quite general script in doc/src/chapters/make_slides.sh for
compiling a slide collection defined in a file like slides_ch2.do.txt.
Just run
Terminal> bash ../make_slides.sh slides_ch2
from the chapter directory. Note that the script will first spell check
the slide files. This is done in the slides-ch2 directory. Errors are
reported in files located in slides-ch2. To update the chapter's dictionary
for spell checking, you need to do
Terminal> cp slides-ch2/new_dictionary.txt~ .dict4spell
in the ch2 chapter directory.
Similarly, to look at misspellings,
the file slides-ch2/misspellings.txt  is the relevant file.
The make_slides.sh script compiles a variety of slides:
reveal.js slides with different colors.deck.js slides. This format is usually inferior to reveal.js,
   but is also very much personal taste.theme=red_shadow line in make_slides.sh
   to control the Beamer theme.Since DocOnce documents can be translated to IPython/Jupyter notebooks, hereafter just called notebooks, it is tempting to produce a version of the teaching material also in notebook form. This author's experience is that a more traditional book format with running text is not so ideal for a notebook:
% if FORMAT != 'ipynb': followed by a FIGURE: line
that includes the resulting figure for all formats except the notebook.
Also be aware of the DocOnce hidden code environment that can
be used to declare code blocks that appear in notebooks (because they
are needed) but not in other formats: !bc pyhid gives a Python
hidden snippet.
Using notebooks as a starting point for a traditional textbook might be a good idea, but will enforce a non-conventional style in the textbook. For example, notebooks should be quite small, leading to similarly small modules in the book. Notebooks use cross-referencing to little extent, and this will be reflected in the textbook too. Notebooks also need more code to run, so one has to accept more code in the textbook. However, there is still a problem for the notebook with defining items for an index, fancy admonitions, and other elements that one would desire in a textbook. More experience is needed to make best practices. Since notebooks can be compiled in Markdown, and DocOnce can read basic Markdown input, it is possible to go from the notebook format to DocOnce, but this is not tested.
More best practices for turning teaching material into books and into notebooks are supposed to be collected here in the future.