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diff --git a/Master/texmf-dist/doc/latex/beamer/beamerug-guidelines.tex b/Master/texmf-dist/doc/latex/beamer/beamerug-guidelines.tex new file mode 100644 index 00000000000..989f3d7070e --- /dev/null +++ b/Master/texmf-dist/doc/latex/beamer/beamerug-guidelines.tex @@ -0,0 +1,973 @@ +% $Header: /cvsroot/latex-beamer/latex-beamer/doc/beamerug-guidelines.tex,v 1.10 2004/12/09 22:31:18 tantau Exp $ + +% Copyright 2003, 2004 by Till Tantau <tantau@users.sourceforge.net>. +% +% This program can be redistributed and/or modified under the terms +% of the GNU Public License, version 2. + +\section{Guidelines for Creating Presentations} + + +\label{section-guidelines} + +In this section I sketch the guidelines that I try to stick to when I +create presentations. These guidelines either arise out of experience, +out of common sense, or out of recommendations by other people or +books. These rules are certainly not intended as commandments that, if +not followed, will result in catastrophe. The central rule of +typography also applies to creating presentations: \emph{Every rule + can be broken, but no rule may be ignored.} + + + + +\subsection{Structuring a Presentation} + +\label{section-structure-guidelines} + + + +\subsubsection{Know the Time Constraints} + +When you start to create a presentation, the very first thing you +should worry about is the amount of time you have for your +presentation. Depending on the occasion, this can +be anything between 2 minutes and two hours. + +\begin{itemize} +\item + A simple rule for the number of frames is that you should have at + most one frame per minute. +\item + In most situations, you will have less time for your presentation + that you would like. +\item + \emph{Do not try to squeeze more into a presentation than time + allows for.} No matter how important some detail seems to you, it is + better to leave it out, but get the main message across, than + getting neither the main message nor the detail across. +\end{itemize} + +In many situations, a quick appraisal of how much time you have will +show that you won't be able to mention certain details. Knowing this can +save you hours of work on preparing slides that you would have to remove +later anyway. + + + +\subsubsection{Global Structure} + +To create the ``global structure'' of a presentation, with the time +constraints in mind, proceed as follows: +\begin{itemize} +\item + Make a mental inventory of the things you can reasonably talk about + within the time available. +\item + Categorize the inventory into sections and subsections. +\item + For very long talks (like a 90 minute lecture), you might also + divide your talk into independent parts (like a ``review of the + previous lecture part'' and a ``main part'') using the |\part| + command. Note that each part has its own table of contents. +\item + Do not feel afraid to change the structure later on as you work on + the talk. +\end{itemize} + + + +\paragraph{Parts, Section, and Subsections.} + +\begin{itemize} +\item + Do not use more than four sections and not less than two per + part. +\end{itemize} +Even four sections are usually too much, unless they follow +a very easy pattern. Five and more sections are simply too hard to +remember for the audience. After all, when you present the table of +contents, the audience will not yet really be able to grasp the +importance and relevance of the different sections and will most +likely have forgotten them by the time you reach them. + +\begin{itemize} +\item + Ideally, a table of contents should be understandable by itself. In + particular, it should be comprehensible \emph{before} someone has + heard your talk. +\item + Keep section and subsection titles self-explaining. +\item + Both the sections and the subsections should follow a logical + pattern. +\item + Begin with an explanation of what your talk is all about. (Do + not assume that everyone knows this. The \emph{Ignorant Audience + Law} states: Someone important in the audience always knows less + than you think everyone should know, even if you take the Ignorant + Audience Law into account.) +\item + Then explain what you or someone else has found out concerning the + subject matter. +\item + Always conclude your talk with a summary that repeats the main + message of the talk in a short and simple way. People pay most + attention at the beginning and at the end of talks. The summary is + your ``second chance'' to get across a message. +\item + You can also add an appendix part using the |\appendix| command. Put + everything into this part that you do not actually intend to talk + about, but that might come in handy when questions are asked. +\item + Do not use subsubsections, they are evil. +\end{itemize} + + + +\paragraph{Giving an Abstract} + +In papers, the abstract gives a short summary of the whole paper in +about 100 words. This summary is intend to help readers appraise +whether they should read the whole paper or not. +\begin{itemize} +\item + Since you audience is unlikely to flee after the first slide, in + a presentation you usually do not need to present an abstract. +\item + However, if you can give a nice, succinct statement of your + talk, you might wish to include an abstract. +\item + If you include an abstract, be sure that it is \emph{not} some long + text but just a very short message. +\item + \emph{Never, ever} reuse a paper abstract for a presentation, + \emph{except} if the abstract is ``We show $\operatorname{P} = + \operatorname{NP}$'' or ``We show $\operatorname{P} \neq + \operatorname{NP}$'' +\item + If your abstract is one of the above two, double-check whether + your proof is correct. +\end{itemize} + + + + + +\paragraph{Numbered Theorems and Definitions.} + +A common way of globally structuring (math) articles and books is to +use consecutively numbered definitions and theorems. Unfortunately, +for presentations the situation is a bit more complicated and I would +like to discourage using numbered theorems in presentations. The +audience has no chance of remembering these numbers. \emph{Never} say +things like ``now, by Theorem~2.5 that I showed you earlier, we have +\dots'' It would be much better to refer to, say, Kummer's Theorem +instead of Theorem~2.5. If Theorem~2.5 is some obscure theorem that +does not have its own name (unlike Kummer's Theorem or Main Theorem or +Second Main Theorem or Key Lemma), then the audience will have +forgotten about it anyway by the time you refer to it again. + +In my opinion, the only situation in which numbered theorems make +sense in a presentation is in a lecture, in which the students can read +lecture notes in parallel to the lecture where the theorems are +numbered in exactly the same way. + +If you do number theorems and definition, number everything +consecutively. Thus if there are one theorem, one lemma, +and one definition, you would have Theorem~1, Lemma~2, and +Definition~3. Some people prefer all three to be numbered~1. I would +\emph{strongly} like to discourage this. The problem is that this +makes it virtually impossible to find anything since Theorem~2 might +come after Definition~10 or the other way round. Papers and, worse, +books that have a Theorem~1 and a Definition~1 are a pain. +\begin{itemize} +\item + Do not inflict pain on other people. +\end{itemize} + + +\paragraph{Bibliographies.} + +You may also wish to present a bibliography at the end of your talk, +so that people can see what kind of ``further reading'' is possible. +When adding a bibliography to a presentation, keep the following in mind: + +\begin{itemize} +\item + It is a bad idea to present a long bibliography in a + presentation. Present only very few references. (Naturally, this + applies only to the talk itself, not to a possible handout.) +\item + If you present more references than fit on a single slide you can be + almost sure that none of them will not be remembered. +\item + Present references only if they are intended as ``further reading.'' + Do not present a list of all things you used like in a paper. +\item + You should not present a long list of all your other great papers + \emph{except} if you are giving an application talk. +\item + Using the |\cite| commands can be confusing since the audience + has little chance of remembering the citations. If you cite the + references, always cite them with full author name and year like + ``[Tantau, 2003]'' instead of something like ``[2,4]'' or + ``[Tan01,NT02]''. +\item + If you want to be modest, you can abbreviate your name when citing + yourself as in ``[Nickelsen and T., 2003]'' or ``[Nickelsen and T, + 2003]''. However, this can be confusing for the audience since it is + often not immediately clear who exactly ``T.'' might be. I recommend + using the full name. +\end{itemize} + + + + +\subsubsection{Frame Structure} + +\label{section-frame-guidelines} +\label{section-guidelines-local} + +Just like your whole presentation, each frame should also be +structured. A frame that is solely filled with some long text is very +hard to follow. It is your job to structure the contents of each frame +such that, ideally, the audience immediately seems which information +is important, which information is just a detail, how the presented +information is related, and so on. + + + +\paragraph{The Frame Title} + +\begin{itemize} +\item + Put a title on each frame. The title explains the contents of the + frame to people who did not follow all details on the slide. +\item + The title should really \emph{explain} things, not just give a + cryptic summary that cannot be understood unless one has understood + the whole slide. For example, a title like ``The Poset'' will have + everyone puzzled what this slide might be about. Titles like + ``Review of the Definition of Partially Ordered Sets (Posets)'' or + ``A Partial Ordering on the Columns of the Genotype Matrix'' are + \emph{much} more informative. +\item + Ideally, titles on consecutive frames should ``tell a story'' all by + themselves. +\item + In English, you should \emph{either} \emph{always} capitalize all words in + a frame title except for words like ``a'' or ``the'' (as in a + title), \emph{or} you \emph{always} use the normal lowercase + letters. Do \emph{not} mix this; stick to one rule. The same is true + for block titles. For example, do not use titles like ``A short + Review of Turing machines.'' Either use ``A Short Review of Turing + Machines.'' or ``A short review of Turing machines.'' (Turing is + still spelled with a capital letter since it is a name). +\item + In English, the title of the whole document should be + capitalized, regardless of whether you capitalize anything else. +\item + In German and other languages that have lots of capitalized words, + always use the correct upper-/lowercase letters. Never capitalize + anything in addition to what is usually capitalized. +\end{itemize} + + + +\paragraph{How Much Can I Put On a Frame?} + +\begin{itemize} +\item + A frame with too little on it is better than a frame with too much + on it. A usual frame should have between 20 and 40 words. The + maximum should be at about 80 words. +\item + Do not assume that everyone in the audience is an expert on the + subject matter. Even if the + people listening to you should be experts, they may last have heard + about things you consider obvious several years ago. You should + always have the time for a quick reminder of what exactly a + ``semantical complexity class'' or an ``$\omega$-complete partial + ordering'' is. +\item + Never put anything on a slide that you are not going to explain + during the talk, not even to impress anyone with how + complicated your subject matter really is. However, you may + explain things that are not on a slide. +\item + Keep it simple. Typically, your audience will see a slide for less + than 50 seconds. They will not have the time to puzzle through long + sentences or complicated formulas. +\item + Lance Forthnow claims: PowerPoint users give better talks. His + reason: Since PowerPoint is so bad at typesetting math, they use + less math, making their talks easier to understand. + + There is some truth in this in my opinion. The great + math-typesetting capabilities of \TeX\ can easily lure you into + using many more formulas than is necessary and healthy. For example, + instead of writing {\catcode `|=12``Since $\left|\{x \in \{0,1\}^* + \mid x \sqsubseteq y\}\right| < \infty$}, we have\dots''\ use ``Since + $y$ has only finitely many prefixes, we have\dots'' + + You will be surprised how much mathematical text can be reformulated + in plain English or can just be omitted. Naturally, if some + mathematical argument is what you are actually talking about, as in + a math lecture, make use of \TeX's typesetting capabilities to your + heart's content. +\end{itemize} + + + +\paragraph{Structuring a Frame} + +\begin{itemize} +\item + Use block environments like |block|, |theorem|, |proof|, |example|, + and so on. +\item + Prefer enumerations and itemize environments over plain text. +\item + Use |description| when you define several things. +\item + Do not use more than two levels of ``subitemizing.'' \beamer\ + supports three levels, but you should not use that third + level. Mostly, you should not even use the second one. Use good + graphics instead. +\item + Do not create endless |itemize| or |enumerate| lists. +\item + Do not uncover lists piecewise. +\item + Emphasis is an important part of creating structure. Use |\alert| to + highlight important things. This can be a single word or a whole + sentence. However, do not overuse hilighting since this will negate + the effect. +\item + Use columns. +\item + \emph{Never} use footnotes. They needlessly disrupt the flow of + reading. Either what is said in the footnote is important and should + be put in the normal text; or it is not important and should be + omitted (\emph{especially} in a presentation). +\item + Use |quote| or |quotation| to typeset quoted text. +\item + Do not use the option |allowframebreaks| except for long + bibliographies. +\item + Do not use long bibliographies. +\end{itemize} + + + + +\paragraph{Writing the Text} + +\begin{itemize} +\item + Use short sentences. +\item + Prefer phrases over complete sentences. For example, + instead of ``The figure on the left shows a Turing machine, the + figure on the right shows a finite automaton.''\ try ``Left: A Turing + machine. Right: A finite automaton.'' Even better, turn this into an + itemize or a description. +\item + Punctuate correctly: no punctuation after phrases, complete + punctuation in and after complete sentences. +\item + \emph{Never} use a smaller font size to ``fit more on a frame.'' + \emph{Never ever} use the \emph{evil} option |shrink|. +\item + Do not hyphenate words. If absolutely necessary, hyphenate words + ``by hand,'' using the command~|\-|. +\item + Break lines ``by hand'' using the command~|\\|. Do not rely on + automatic line breaking. Break where there is a logical pause. For + example, good breaks in ``the tape alphabet is larger + than the input alphabet'' are before ``is'' and before the second + ``the.'' Bad breaks are before either ``alphabet'' and before + ``larger.'' +\item + Text and numbers in figures should have the \emph{same} size as + normal text. Illegible numbers on axes usually ruin a chart and its + message. +\end{itemize} + + + + +\subsubsection{Interactive Elements} + +Ideally, during a presentation you would like to present your +slides in a perfectly linear fashion, presumably by pressing the +page-down-key once for each slide. However, there are different +reasons why you might have to deviate from this linear order: +\begin{itemize} +\item + Your presentation may contain ``different levels of detail'' that + may or may not be skipped or expanded, depending on the audience's + reaction. +\item + You are asked questions and wish to show supplementary slides. +\item + You present a complicated picture and you have to ``zoom out'' + different parts to explain details. +\item + You are asked questions about an earlier slide, which forces you to + find and then jump to that slide. +\end{itemize} +You cannot really prepare against the last kind of questions. In this +case, you can use the navigation bars and symbols to find the slide +you are interested in, see \ref{section-navigation-bars}. + +Concerning the first three kinds of deviations, there are several +things you can do to prepare ``planned detours'' or ``planned +short cuts''. +\begin{itemize} +\item + You can add ``skip buttons.'' When such a button + is pressed, you jump over a well-defined part of your talk. Skip + button have two advantages over just pressing the forward key + is rapid succession: first, you immediately end up at the correct + position and, second, the button's label can give the audience a + visual feedback of what exactly will be skipped. For example, when + you press a skip button labeled ``Skip proof'' nobody will start + puzzling over what he or she has missed. +\item + You can add an appendix to your talk. The appendix is kept + ``perfectly separated'' from the main talk. Only once you ``enter'' + the appendix part (presumably by hyperjumping into it), does the + appendix structure become visible. You can put all frames that you + do not intend to show during the normal course of your talk, but + which you would like to have handy in case someone asks, into this + appendix. +\item + You can add ``goto buttons'' and ``return buttons'' to create + detours. Pressing a goto button will jump to a certain part of the + presentation where extra details can be shown. In this part, there + is a return button present on each slide that will jump back to the + place where the goto button was pressed. +\item + In \beamer, you can use the |\againframe| command to ``continue'' + frames that you previously started somewhere, but where certain + details have been suppressed. You can use the |\againframe| command + at a much later point, for example only in the appendix to show + additional slides there. +\item + In \beamer, you can use the |\framezoom| command to create links to + zoomed out parts of a complicated slide. +\end{itemize} + + + + + +\subsection{Using Graphics} + +Graphics often convey concepts or ideas much more efficiently than +text: A picture can say more than a thousand words. (Although, +sometimes a word can say more than a thousand pictures.) + +\begin{itemize} +\item + Put (at least) one graphic on each slide, whenever + possible. Visualizations help an audience enormously. +\item + Usually, place graphics to the left of the text. (Use the + |columns| environment.) In a left-to-right reading culture, we look + at the left first. +\item + Graphics should have the same typographic parameters as the + text: Use the same fonts (at the same size) in graphics as in the + main text. A small dot in a graphic should have exactly the same + size as a small dot in a text. The line width should be the same as + the stroke width used in creating the glyphs of the font. For + example, an 11pt non-bold Computer Modern font has a stroke width of + 0.4pt. +\item + While bitmap graphics, like photos, can be much more colorful than the + rest of the text, vector graphics should follow the same ``color + logic'' as the main text (like black~= normal lines, red~= hilighted + parts, green~= examples, blue~= structure). +\item + Like text, you should explain everything that is shown on a + graphic. Unexplained details make the audience puzzle whether this + was something important that they have missed. Be careful when + importing graphics from a paper or some other source. They usually + have much more detail than you will be able to explain and should be + radically simplified. +\item + Sometimes the complexity of a graphic is intensional and you + are willing to spend much time explaining the graphic in great + detail. In this case, you will often run into the problem that fine + details of the graphic are hard to discern for the audience. In this + case you should use a command like |\framezoom| to create + anticipated zoomings of interesting parts of the graphic, see + Section~\ref{section-zooming}. +\end{itemize} + + + +\subsection{Using Animations and Transitions} + +\begin{itemize} +\item + Use animations to explain the dynamics of systems, algorithms, etc. +\item + Do \emph{not} use animations just to attract the attention of your + audience. This often distracts attention away from the main topic of the + slide. No matter how cute a rotating, + flying theorem seems to look and no matter how badly you feel your + audience needs some action to keep it happy, most people in the + audience will typically feel you are making fun of them. +\item + Do \emph{not} use distracting special effects like ``dissolving'' + slides unless you have a very good reason for using them. If you use + them, use them sparsely. + They \emph{can} be useful in some situations: For example, you might + show a young boy on a slide and might wish to dissolve this slide + into slide showing a grown man instead. In this case, the + dissolving gives the audience visual feedback that the young boy + ``slowly becomes'' the man. +\end{itemize} + + + + +\subsection{Choosing Appropriate Themes} + +\beamer\ comes with a number of different themes. When choosing a +theme, keep the following in mind: + +\begin{itemize} +\item + Different themes are appropriate for different occasions. Do not + become too attached to a favorite theme; choose a + theme according to occasion. +\item + A longer talk is more likely to require navigational hints + than a short one. When you give a 90 minute lecture to students, you + should choose a theme that always shows a sidebar with the current + topic hilighted so that everyone always knows exactly what's the + current ``status'' of your talk is; when you give a ten-minute + introductory speech, a table of contents is likely to just seem + silly. +\item + A theme showing the author's name and affiliation is appropriate in + situation where the audience is likely not to know you (like during + a conference). If everyone knows you, having your name on each slide + is just vanity. +\item + First choose a presentation theme that has a layout that is + appropriate for your talk. +\item + Next you might wish to change the colors by installing a different + color theme. This can drastically change the appearance of your + presentation. A ``colorful'' theme like |Berkeley| will look much + less flashy if you use the color themes |seahorse| and |lily|. +\item + You might also wish to change the fonts by installing a different + font theme. +\end{itemize} + + + +\subsection{Choosing Appropriate Colors} + +\begin{itemize} +\item + Use colors sparsely. The prepared themes are already quite + colorful (blue~= structure, red~= alert, green~= example). If you + add more colors for things like code, math text, etc., you should + have a \emph{very} good reason. +\item + Be careful when using bright colors on white background, + \emph{especially} when using green. What looks good on your monitor + may look bad during a presentation due to the different ways + monitors, beamers, and printers reproduce colors. Add lots of black + to pure colors when you use them on bright backgrounds. +\item + Maximize contrast. Normal text should be black on white or at least + something very dark on something very bright. \emph{Never} do things + like ``light green text on not-so-light green background.'' +\item + Background shadings decrease the legibility without increasing the + information content. Do not add a background shading just because it + ``somehow looks nicer.'' +\item + Inverse video (bright text on dark background) can be a problem + during presentations in bright environments since only a small + percentage of the presentation area is light up by the + beamer. Inverse video is harder to reproduce on printouts and on + transparencies. +\end{itemize} + + + + + + +\subsection{Choosing Appropriate Fonts and Font Attributes} + +Text and fonts literally surround us constantly. Try to think of the +last time when there was no text around you within ten +meters. Likely, this has never happened in your life! +(Whenever you wear clothing, even a swim suit, there is a lot of text +right next to your body.) The history of fonts is nearly as long as +the history of civilization itself. There are tens of thousands of fonts +available these days, some of which are the product of hundreds of +years of optimization. + +Choosing the right fonts for a presentation is by no means +trivial and wrong choices will either just ``look bad'' or, worse, +make the audience having trouble reading your slides. +This user's guide cannot replace a good book on typography, but in the +present section you'll find several hints that should help you setup +fonts for a \beamer\ presentation that look good. +A font has numerous attributes like weight, family, or size. All of +these have an impact on the usability of the font in +presentations. In the following, these attributes are described and +advantages and disadvantages of the different choices are sketched. + + +\subsubsection{Font Size} + +\label{section-sizes} + +Perhaps the most obvious attribute of a font is its size. Fonts are +traditionally measured in ``points.'' How much a point is depends on +whom you ask. \TeX\ thinks a point is the 72.27th part of an inch, +which is 2.54 cm. On the other hand, PostScript and Adobe think a +point is the 72th part of an inch (\TeX\ calls this a big point). The +are differences between American and European points. Once it is +settled how much a point is, claiming that a text is in ``11pt'' means +that the ``height'' of the letters in the font are 11pt. However, this +``height'' stems from the time when letters where still cast in lead +and refers to the the vertical size of the lead letters. It thus does +not need to have any correlation with the actual height of, say, the +letter x or even the letter M. The letter x of an 11pt Times from +Adobe will have a height that is different from the height of the +letter x of an 11pt Times from UTC and the letter x of an 11pt +Helvetica from Adobe will have yet another height. + +Summing up, the font size has little to do with the actual size of +letters. Rather, these days it is a convention that 10pt or 11pt is +the size a font should be printed for ``normal reading.'' Fonts are +designed so that they can optimally be read at these sizes. + +In a presentation the classical font sizes obviously loose their +meaning. Nobody could read a projected text if it were actually +11pt. Instead, the projected letters need to be several centimeters +high. Thus, it does not really make sense to specify ``font sizes'' +for presentations in the usual way. Instead, you should try to think +of the number of lines that will fit on a slide if you were to fill +the whole slide with line-by-line text (you are never going to do that +in practice, though). Depending on how far your audience is removed +from the projection and on how large the projection is, between 10 and +20 lines should fit on each slide. The less lines, the more readable +your text will be. + +In \beamer, the default sizes of the fonts are chosen in a way that +makes it difficult to fit ``too much'' onto a slide. Also, it will +ensure that your slides are readable even under bad conditions like a +large room and a small only a small projection area. However, you may +wish to enlarge or shrink the fonts a bit if you know this to be more +appropriate in your presentation environment. + +Once the size of the normal text is settled, all other sizes are +usually defined relative to that size. For this reason, \LaTeX\ has +commands like |\large| or |\small|. The actual size these commands +select depends on the size of normal text. + +In a presentation, you will want to use a very small font for text in +headlines, footlines, or sidebars since the text shown there is not +vital and is read at the audience's leasure. Naturally, the text should +still be large enough that it actually \emph{can} be read without +binoculars. However, in a normal presentation environment the audience +will still be able to read even |\tiny| text when necessary. + +However, using small fonts can be tricky. Many PostScript fonts are +just scaled down when used at small sizes. When a font is +used at less than its normal size, the characters should actually be +stroked using a slightly thicker ``pen'' than the one resulting from +just scaling things. For this reason, high quality +multiple master fonts or the Computer Modern fonts use different +fonts for small characters and for normal characters. However, when +you use a normal Helvetica or Times font, the characters are just +scaled down. A similar problem arises when you use a light font on a +dark background. Even when printed on paper in high resolution, +light-on-dark text tends to be ``overflooded'' by the dark +background. When light-on-dark text is rendered in a presentation this +effect can be much worse, making the text almost impossible to read. + +You can counter both negative effects by using a bold versions for +small text. + +In the other direction, you can use larger text for titles. However, +using a larger font does not always have the desired effect. Just +because a frame title is printed in large letters does not +mean that it is read first. Indeed, have a look at the cover of your +favorite magazine. Most likely, the magazine's name is the typeset in the +largest font, but you your attention will nevertheless first go to the +topics advertised on the cover. Likewise, in the table of contents you +are likely to first focus on the entries, not on the words ``Table of +Contents.'' Most likely, you would not spot a spelling mistake there +(a friend of mine actually managed to misspell \emph{his own name} on +the cover of his master's thesis and nobody noticed until a year +later). In essence, large text at the top of a page signals +``unimportant since I know what to expect.'' So, instead of using a +very large frame title, also consider using a normal size frame title +that is typeset in bold or in italics. + + + + + +\subsubsection{Font Families} + +\label{section-guidelines-serif} + +The other central property of any font is its family. Examples of font +families are Times or Helvetica or Futura. As the name suggests, a lot +of different fonts can belong to the same family. For example, Times +comes in different sizes, there is a bold version of Times, an +italics version, and so on. To confuse matters, font families like +Times are often just called the ``font Times.'' + +The are two large classes of font families: serif fonts and +sans-serif fonts. A sans-serif font is a font in +which the letters do not have serifs (from French \emph{sans}, which +means ``without''). Serifs are the little hooks at the ending of the +strokes that make up a letter. The font you are currently reading is a +serif font. \textsf{By comparison, this text is in a sans-serif font.} +Sans-serif fonts are (generally considered to be) easier to read +when used in a presentation. In low resolution rendering, serifs +decrease the legibility of a font. However, on projectors with very +high resolution serif text is just as readable as sans-serif text. A +presentation typeset in a serif font creates a more conservative +impression, which might be exactly what you wish to create. + +Most likely, you'll have a lot of different font families preinstalled +on you system. The default font used by \TeX\ (and \beamer) is the +Computer Modern font. It is the original font family designed by Donald +Knuth himself for the \TeX\ program. It is a mature font that comes +with just about everything you could wish for: extensive mathematical +alphabets, outline PostScript versions, real small caps, real oldstyle +numbers, specially designed small and large letters, and so on. + +However, there are reasons for using font families other than Computer +Modern: +\begin{itemize} +\item + The Computer Modern fonts are a bit boring if you have seen them too + often. Using another font (but not Times!) can give a fresh look. +\item + Other fonts, especially Times and Helvetica, are sometime rendered + better since they seem to have better internal hinting. +\item + The sans-serif version of Computer Modern is not nearly as + well-designed as the serif version. Indeed, the sans-serif version + is, in essence, the serif version with different design parameters, + not an independent design. +\item + Computer modern needs much more space than more economic fonts like + Times (this explains why Times is so popular with people who need + to squeeze their great paper into just twelve pages). To be fair, + Times was specifically designed to be economic (the newspaper + company publishing The Times needed robust, but space-economic font). +\end{itemize} + +A small selection of alternatives to Computer Modern: +\begin{itemize} +\item + Helvetica is an often used alternative. However, Helvetica also + tends to look boring (since we see it everywhere) and it has a very + large x-height (the height of the letter~x in comparison to a letter + like~M). A large x-height is usually considered good for languages + (like English) that use uppercase letters seldomly and not-so-good + for languages (like German) that use uppercase letters a lot. (I + have never been quite convinced by the argument for this, though.) + Be warned: the x-height of Helvetica is so different from the + x-height of Times that mixing the two in a single line looks + strange. The packages for loading Times and Helvetica provide + options for fixing this, though. +\item + Futura is, in my opinion, a beautiful font that is very well-suited + for presentations. Its thick letters make it robust against + scaling, inversion, and low contrast. Unfortunately, while it is + most likely installed on your system somewhere in some form, getting + \TeX\ to work with it is a complicated process. +\item + Times is a possible alternative to Computer Modern. Its main + disadvantage is that it is a serif font, which requires a + high-resolution projector. Naturally, it also used very often, so we + all know it very well. +\end{itemize} + +Families that you should \emph{not} use for normal text include: +\begin{itemize} +\item + All monospaced fonts (like Courier). +\item + Script fonts (which look like handwriting). Their stroke width is + way too small for a presentation. +\item + More delicate serif fonts like Stempel and possibly even Garamond + (though Garamond is really a beautiful font for books). +\item + Gothic fonts. Only a small fraction of your audience will be able to + read them fluently. +\end{itemize} + +There is one popular font that is a bit special: Microsoft's Comic +Sans. On the one hand, there is a website lobbying for banning the use +of this font. Indeed, the main trouble with the font is that it is not +particularly well-readable and that math typeset partly using this +font looks terrible. On the other hand, this font \emph{does} create +the impression of a slide ``written by hand,'' which gives the +presentation a natural look. Think twice before using this font, but +do not let yourself be intimidated. + +One of the most important rules of typography is that you should use +as little fonts as possible in a text. In particular, typographic +wisdom dictates that you should not use more than two different +families on one page. However, when typesetting +mathematical text, it is often necessary and useful to use different +font families. For example, it used to be common practice to use +Gothic letters do denote vectors. Also, program texts are often +typeset in monospace fonts. If your audience is used to a certain font +family for a certain type of text, use that family, regardless of what +typographic wisdom says. + +A common practice in typography is to use a sans serif fonts for +titles and serif fonts for normal text (check your favorite +magazine). You can \emph{also} use two different sans serif fonts or +two different serif fonts, but you then have to make sure that the +fonts look ``sufficiently different.'' If they look only slightly +different, the page will look ``somehow strange,'' but the audience +will not be able to tell why. For example, do not mix Arial and +Helvetica (they are almost identical) or Computer Modern and +Baskerville (they are quite similar). A combination of Gills Sans and +Helvetica is dangerous but perhaps possible. A combination like Futura +and Optima is certainly ok, at least with respect to the fonts being +very different. + + + + +\subsubsection{Font Shapes: Italics and Small Capitals} + +\label{section-italics} +\label{section-smallcaps} + +\LaTeX\ introduces the concept of the \emph{shape} of a font. The only +really important ones are italic and small caps. +An \emph{italic} font is a font in which the text is slightly slanted +to the right \emph{like this}. Things to know about +italics: +\begin{itemize} +\item + Italics are commonly used in novels to express emphasis. However, + especially with sans-serif fonts, italics are typically not ``strong + enough'' and the emphasis gets lost in a presentation. Using a + different color or bold text seems better suited for presentations + to create emphasis. +\item + If you look closely, you will notice that italic text is not only + slanted but that different letters are actually used (compare a and + \emph{a}, for example). However, this is only true for serif text, + not for sans-serif text. Text that is only slanted without using + different characters is called ``slanted'' instead of ``italic.'' + Sometimes, the word ``oblique'' is also used for slanted, but it + sometimes also used for italics, so it is perhaps best to avoid + it. Using slanted serif text is very much frowned upon by + typographers and is considered ``cheap computer typography.'' + However, people who use slanted text in their books include Donald + Knuth. + + In a presentation, if you go into the trouble of using a serif font + for some part of it, you should also use italics, not slanted text. +\item + The different characters used for serif italics have changed much + less from the original handwritten letters they are based on than + normal serif text. For this reason, serif italics creates the + impression of handwritten text, which may be desirable to give a + presentation a more ``personal touch'' (although you can't get very + personal using Times italics, which everyone has seen a thousand + times). However, it is harder to read than normal text, so do not + use it for text more than a line long. +\end{itemize} + +The second font shape supported by \TeX\ are small capital +letters. Using them can create a conservative, even formal +impression, but some words of caution: + +\begin{itemize} +\item + Small capitals are different from all-uppercase text. A small caps + text leaves normal uppercase letters unchanged and uses smaller + versions of the uppercase letters for normal typesetting lowercase + letters. Thus the word ``German'' is typeset as \textsc{German} + using small caps, but as \uppercase{German} using all uppercase + letters. +\item + Small caps either come as ``faked'' small caps or as ``real'' + small caps. Faked small caps are created by just scaling down + normal uppercase letters. This leads to letters the look too + thin. Real small caps are specially designed smaller versions of + the uppercase letters that have the same stroke width as normal + text. +\item + Computer Modern fonts and expert version of PostScript fonts come + with real small caps (though the small caps of Computer Modern are + one point size too large for some unfathomable reason---but your + audience is going to pardon this since it will not notice + anyway). ``Simple'' PostScript fonts like out-of-the-box Helvetica + or Times only come with faked small caps. +\item + Text typeset in small caps is harder to read than normal text. The + reason is that we read by seeing the ``shape'' of words. For + example, the word ``shape'' is mainly recognized by seing one + normal letter, one ascending letter, a normal letter, one + descending letter, and a normal letter. One has much more trouble + spotting a misspelling like ``shepe'' than ``spape''. Small caps + destroy the shape of words since \textsc{shape}, \textsc{shepe} + and \textsc{spape} all have the same shape, thus making it much + harder to tell them apart. Your audience will read small caps more + slowly than normal text. This is, by the way, why legal + disclaimers are often written in uppercase letters: not to make + them appear more important to you, but to make them much harder to + actually read. +\end{itemize} + + + +\subsubsection{Font Weight} + +The ``weight'' of a font refers to the thickness of the +letters. Usually, fonts come as regular or as bold fonts. There often +also exist semibold, ultrabold (or black), thin, or ultrathin (or hair) +versions. + +In typography, using a bold font to create emphasis, especially within +normal text, is frowned upon (bold words in the middle of a normal +text are referred to as ``dirt''). For presentations this rule of not +using bold text does not really apply. On a presentation slide there +is usually very little text and there are numerous elements that try +to attract the viewer's attention. Using the traditional italics to +create emphasis will often be overlooked. So, using bold text, seems a +good alternative in a presentation. However, an even better +alternative is using a bright color like red to attract attention. + +As pointed out earlier, you should use bold text for small text +unless you use an especially robust font like Futura. + + + +%%% Local Variables: +%%% mode: latex +%%% TeX-master: "beameruserguide" +%%% End: |