Friday, January 8, 2010

A Few Tips on How to Use PowerPoint for Mathematical Presentations

What These Are About
These tips may help you produce math-heavy PowerPoint presentations more efficiently, and get them to look better. They assume familiarity with the basics of PowerPoint. They do not argue for or against using PowerPoint for your presentations (there are many pros and cons). They were born out of a conversation among graduate students in the MIT theory group sometime in 1999 or 2000, when many of us were discovering PowerPoint and agreed that a page for sharing tips would be useful. Some of them are probably getting out of date as newer versions of PowerPoint come out.

They are maintained by Leonid Reyzin. Please contact me if you have additional tips you think should be included, or if you find something wrong (or no longer applicable).

Machine Independence
One of the biggest headaches with PowerPoint is the difficulty of getting it to look the same on different machines. To that end:

* Make sure your file includes fonts. This is accomplished by going to the "File" menu, selecting "Save As," and checking the "Embed TrueType" check box in the dialog box that pops up. Then click "Save." Your file will likely become very large once you do this, and you may need to compress it to get it to fit a single floppy (see also "Miscellaneous PowerPoint Tips," below, for how to deal with large files).
* If you use Equation Editor/MathType, you need to embed those fonts, as well. Unfortunately, PowerPoint doesn't know you are using those fonts simply because an equation is embedded (it treats equations as graphics); thus, you need to make sure that at least one character from each font used in your equations appears somewhere (e.g., on a special slide, or as white on white, or just a space) in an ordinary PowerPoint textbox. The fonts you are interested in are MTExtra, Euclid Math One and Euclid Math Two. Then use "Embed TrueType" option described above. (Thanks to Bob Mathews for the tip.)

Making Overlays
Get everything you want onto one slide, and get in its final form. Then split it into overlays as follows: copy it as many times as the number of overlays, and simply "hide" parts on each slide. To hide a part, change its color to white, or cover it up with a white rectangle. Do not delete text, because that will move other text around, and your overlays won't match. Instead, change its color to white.
Typesetting Math
One way to typeset mathematical formulas and symbols in PowerPoint is to use TexPoint add-in. I haven't tried it myself, but have heard good things about it. Just save often, because PowerPoint's tendency to crash apparently only increases when the add-in is used (in particular, when the LaTeX interpreter is closed improperly).

If you prefer to use "straight" PowerPoint, here are some tips.

1. Getting it to look good
* Italicize only what should be italicized. Generally, this means only Roman and Greek variable names (italicizing uppercase Greek is optional). Be sure to not italicize plus and minus signs, function like log and cos, numerals, parentheses, etc. If in doubt about what should be italicized in a particular formula, typeset it in LaTeX and then mimic LaTeX's output in PowerPoint. To toggle italics, just use Ctrl-i.
* Use Times New Roman or a similar font. Sans serif fonts, such as Helvetica, are not good for math (although they may be good for the rest of your presentation). It's ok to have one font for math and another for the text (the slides class of LaTeX does that, in fact). To change fonts without using the mouse, use Ctrl-Shift-f and arrow keys.
* You can also change fonts and styles by using the "format painter" button: simply get one character to look right, and then use the format painter to copy its format to other similar characters. (Thanks to Shane Scott for this tip.)
* Do not use a hyphen for a minus sign. A much better minus sign is an en-dash. Unfortunately, it is a bit hard to get in PowerPoint. See "Inserting non-standard characters" below.
* When you copy math around, make sure it has the same font size as the surrounding text. PowerPoint will not always automatically get it right.

2. Inserting non-standard characters.
* To insert Greek letters, simply type the "corresponding" Roman letter (e.g., "a" for alpha, "t" for tau, "q" for theta), and then change its font to Symbol. Same for "sum" and "product" symbols: simply use capital sigma and capital pi.
* Standart Unicode symbols for integrals don't look any good. You may want to use the curve-line tool to make one and then copy it around. (Thanks to Nikola Venkov for this tip.)
* To insert the many special symbols that are available in Microsoft Word (such as en- and em-dashes, ©, etc.), simply open up Microsoft Word, and insert them using the menu "Insert" then "Symbol." The "Special Characters" tab is particularly useful, and contains handy keyboard shortcuts. Once you get it in Microsoft Word, simply select it, copy it, and then paste into your PowerPoint text. Make sure the result has the correct font and size. Then you can copy it around your PowerPoint file whenever you need it.
* More recent versions of PowerPoint have the "Symbol..." item in the "Insert" menu (the corresponding toolbar button is available, as well: see "Miscellaneous PowerPoint tips," below). You can insert characters from various fonts.
* A host of characters is available in the "Character Map" accessory. (Go to the "Start" button, then "Applications," then "Accessories," then "Character Map.") Trying different fonts to find what you need; Symbol font is particularly useful for math. You can select and copy characters, then paste over to PowerPoint. Moreover, if you click on a particular character, you get the "keyboard code" for it displayed at the bottom. Once you learn the keyboard code, you can type it directly in PowerPoint without having to copy and paste. For example, the code for an en-dash (which is good for minus signs) in Times New Roman font is Alt-0150 (hold down Alt, press 0150 on the numeric keypad, then let go of Alt). The code may be different in other fonts.

3. Subscripts and superscripts
* To make subscripts and superscripts using the menus, select the character you need, then go to "Format" then "Font." Note that you can get double superscripts, subscripts of superscripts, etc., by varying the "offset" amount.
* It is faster to make standard subscripts and superscripts using the keyboard. Ctrl-= toggles the subscript flag, and Ctrl-+ (same as Ctrl-Shift-=) toggles the superscript flag. For example, to get aixi, type "a, Ctrl-=, i, Ctrl-=, x, Ctrl-+, i, Ctrl-+" (don't forget to turn on italics at the beginning by "Ctrl-i").
* You can also get buttons for making subscripts and superscripts on your toolbar. See "Miscellaneous PowerPoint Tips" below. Or you can use the format painter: get a single subscript to look right, and then copy its format to other subscripts (see "Getting it to look good" above).

4. More complex formulas.
* You may avoid using Equation Editor/MathType (see "Machine Independence" above) by utilizing multiple text boxes instead. You can move them around to get them in the right positions. Note that large parentheses, brackets, braces, and other useful shapes are available under "AutoShapes" (most likely on your drawing toolbar). Once you get a formula to look right, group all of its components (see "Drawing" below), so you can easily move it around and copy it.

Drawing

* Learn to use "Group," "Ungroup" and "Regroup" in your "Draw" menu (also on your right-click menu). "Regroup" is particularly handy if you need to ungroup to modify something little. You don't have to reselect everything to group it back: simply choose "Regroup."
* To select multiple objects, hold down the Shift key as you click on them with the mouse.
* It is a pain to select text boxes, because when you click inside them, you get to edit text. If that happens, press "escape," and the text box becomes selected. Alternatively, hold down the Shift key as you click. Conversly, if you've selected a text box and now want to edit its text, press "enter."
* It is often easier to nudge objects by selecting them and using arrow keys, rather than by using the mouse.
* Connectors (available under "AutoShapes" on your drawing toolbar) are great when drawing graphs, trees, etc. They can be made to stick to an object, so when you move nodes around, edges adhere to them.

Layout and Design Tips

* You do not have to be stuck with the standard boring slide style. Play around with it by going to the Edit menu, and selecting Master, then Slide Master.
* When giving a talk that will be projected (rather than printed out on transparencies), the color combination that is easiest on the eyes is yellow (or white) on a blue background. (Thanks to Steven Rudich for this tip.)
* To make small caps font style (equivalent to LaTeX's \textsc command), type in all uppercase letters. Then select all the letters you actually want to be in small caps (i.e., not the ones you want to actually be uppercase, such as first letters of sentences), and simply make the font about four points smaller. (Thanks to Amit Sahai for this tip.)
* To start a new line without starting a new paragraph: press "Shift-Enter."

Miscellaneous PowerPoint Tips

* You can customize your toolbars. In particular, it is handy to have buttons for "Format-Subscript," "Format-Superscript," and "Insert-Symbol." Go to the Tools menu, then Customize, then click on the "Commands" tab. Then simply find a command you want by looking at the various categories, and drag it out of the dialog directly onto a toolbar you want. (Thanks to Amit Sahai for this tip.)
* If AutoCorrect annoys you (e.g., you have a variable named "i" and don't want PowerPoint to automatically capitalize it every time), check out the menu "Tools" then "AutoCorrect." If it doesn't annoy you but is just occasionally wrong, you can undo what it just corrected by pressing Ctrl-Z or selecting "Undo" in the "Edit" menu.
* If you file is too large to fit on a single floppy and you need to take it with you, use the "Pack and Go" command in the File menu. Be sure to check the boxes that "Include linked files" and "Embed TrueType fonts" in the dialog boxes that follow. Prepare a large box of floppies, as PowerPoint manages to only enlarge your file as it "compresses" it. However, the packing and restoration procedure is automated, and beats trying to split the file into multiple chunks yourself. Don't forget to label the floppy disks in numerical order; run the application that is included on the first floppy to restore the file to another computer.

No comments:

Post a Comment