When to emphasize text in formal texts? [closed]

Question

Text can be emphasized in LaTeX using \emph or \textit. For what kinds of text or situations is it recommended to use such emphasis in formal texts? For example, in an article, paper or thesis, when and on what elements should one apply emphasis (or italics)?

Answer 1

On the method of creating emphasis in LaTeX: It's better to use \emph than \textit for two reasons. First, \emph -- in keeping with LaTeX's philosophy of separating logical markup from content -- stresses the logic behind the emphasis-creating command, whereas \textit mixes it up with a reference to the actual font shape (italics) used to create the emphasis. Should you ever decide to use, say, a slanted roman font rather than a true italic font for emphasis, doing so is trivially easy if you've been using the \emph command all along, but it'll involve tracking down, checking, and editing lots of \textit commands if you've been using the latter command. In addition, if your main text font is a sans-serif font, the associated emphasis-oriented font is frequently a slanted sans-serif font rather than a true italic; in such circumstances, using the command \textit is bound to create confusion. Second, and maybe of lesser importance, \emph lets you create emphasis-within-emphasis, meaning that if you need to emphasize a particular word or two within a sentence that's already emphasized, then the interior \emph command will automatically switch to "regular" upright (usually Roman) font. Much easier to achieve than if you've been using \textit commands and then have to figure out the command (\upshape) to invoke the upright font by hand.

Separately, you ask when and where to use emphasis in "formal" texts. (By "formal texts," I assume you mean texts that don't consist of listings of computer code, say.) By the way, a very good general reference on the topic of the use of emphasis is Robert Bringhurst's book, "The Elements of Typographic Style." Another resource to consider is the Wikipedia page on the uses and methods for emphasis in typography, available at http://en.wikipedia.org/wiki/Emphasis_%28typography%29.

It is certainly widely preferred in good typography to use an italic font (or slanted-roman font, if you prefer) for emphasis within running text rather than to use boldface or, gasp, to underline words. What exactly should be emphasized will of course depend greatly (nearly exclusively?!) on what the formal text is about and what its main points are. The text in the bodies of theorems, corollaries, etc. is often typeset in emphasized mode, presumably both to highlight the importance of the material and to provide a visual offset from the material that comes before and after such environments. In fiction literature, thoughts that a character expresses to him/herself without saying them out loud are very frequently rendered in emphasized mode. Foreign-language words in running text are often set in italics; in this case, it's not so much for emphasis than it's to flag the special form/usage of the words to the readers who might otherwise become confused.

The possibilities for using emphasis to aid your readers' understanding are unbounded, I'm sure.

Answer 2

From Knuth's TeX Book, here is some consideration:

Typographic conventions are presently in a state of transition, because new technology has made it possible to do things that used to be prohibitively expensive; people are wrestling with the question of how much to use their new-found typographic freedom. Slanted roman type was introduced in the 1930s, but it first became widely used as an alternative to the conventional italic during the late 1970s. It can be beneficial in mathematical texts, since slanted letters are distinguishable from the italic letters in math formulas. The double use of italic type for two different purposes -- for example, when statements of theorems are italicized as well as the names of variables in those theorems -- has led to some confusion, which can now be avoided with slanted type. People are not generally agreed about the relative merits of slanted versus italic, but slanted type is rapidly becoming a favorite for the titles of books and journals in bibliographies.