STYLISTIC COMMENTS I tend to make the same set of comments over and over when I proofread scientific writing, so I thought I'd gather them together into one place for easy reference. 1. Comma usage. 1a. Use a comma after "but", "next", "here", "now", "then", adverbs etc., when starting a sentence. Then, your text will flow nicely. 1b. In case your sentence has one, always use a comma to set off a leading prepositional phrase. 1c. Use commas to set off "parenthetical" type phrases, which many people use, embedded in the sentence. 1d. As you, I, and everyone else knows, commas are important in lists. 1e. It is customary to use commas when joining two sentences together into one, so don't forget. 1f. Use "which" only after a comma, because it is used to add descriptive features instead of defining features. So, "the ball which I threw" should either be "the ball that I threw" (meaning, "of the many possible balls, I'm talking about the thrown one") or "the ball, which I threw" (meaning, "that ball I'm talking about, you might also like to know that I threw it"). Of all the rules that I have learned, I make a special effort to follow this one, which I learned from my advisor. 1g. Avoid using commas for situations not on this list even if you want to add one because it feels like you want to take a breath. (I added this block recently, so I'm not sure how comprehensive it is yet.) 2. Apostrophe usage. 2a. Pluralize abbreviations using an "s". So, use "MDPs", not "MDP's" to mean "Markov decision processes". 2b. Master "its" vs. "it's". "Its" is possessive and "it's" is a contraction for "it is". So, we say "It's unfortunate that its nose fell off." In my experience with this rule, it's common for people to forget its proper usage. 3. Clear, direct language. 3a. Avoid the dangling "this". So, "this example shows that" not "this shows that". This rule is intended to discourage this kind of behavior. One hint: Try changing "this" to "it"---usually, doing so will make it obvious that more context is needed. 3b. To avoid cluttering your sentences, change "in order to" to simply "to". 3c. To use simple words when appropriate, change "utilize" to "use". 4. Dash/hyphen usage. 4a. Hyphenate noun phrases if they defy the natural right-to-left grouping in English. So, "relational reinforcement learning" is ok, but "reinforcement learning algorithm" should be "reinforcement-learning algorithm". Noun-phrase hyphenation is needed to group words in the beginning of a noun phrase, but not when there are only two words. [A nice example from The Colbert Report: "Nazi-treasure hunter" (someone seeking Nazi treasure) vs. "Nazi treasure hunter" (a Nazi who is seeking treasure).] 4b. Know when to use different lengths of dashes. It is state-of-the-art usage to employ a short dash (hyphen, single dash in LaTeX) within words. Ranges require a slightly longer dash; they are written with a double dash (en-dash) in LaTeX as explained in pages 14--33 of Lamport's LaTeX guide. To set off a phrase---something many people do---use even longer dashes with no spaces before or after them (em-dash, written as a triple dash in LaTeX). 5. Usage related to confusable pairs. 5a. led/lead. Perhaps because of the pronunciation of the name of the element "lead", some people are led to believe that the past tense of the verb "lead" can spelled the same way. 5b. affect/effect. They are pronounced similarly and they both can be used as nouns and verbs. It's a recipe for disaster. It affects the clarity of your writing if you mix up these words. The end effect is that people are frustrated because they aren't sure what you said. You can effect change in their affect if you get it right the first time. 5c. bare/bear. Bear with me, because you'll want to bring the right rule to bear. "Bear" can mean the animal or various things related to the idea of exertion. "Bare" is connected with nakedness. They seem quite unrelated but sometimes people can barely tell the difference. I guess you just need to grin and bear it with your bared teeth. 5d. it's/its. See 2b. 6. Use one- vs. two-word phrases correctly. These phrases should be one word when used as a noun and two words when used as a verb. For example, "We trade off time and energy." and "We strike a careful tradeoff between time and energy." Another one: "We set the cutoff to 0.7%, but had to cut off any runs that took too long." Another: "We print out the data and pick up the printout later from the pickup box." And: "I will write up my experiment and then send the writeup to my supervisor." Longer list: follow up, followup; trade off, tradeoff; speed up, speedup; cut off, cutoff; print out, printout; write up, writeup; set up, setup; pick up, pickup; in line, inline; make up, makeup. 7. Usages related to paper structure. 7a. Don't use citations as nouns. Say "As explained by Kearns and Singh (2002)" or "As explained elsewhere (Kearns and Singh 2002)" instead of "As explained by (Kearns and Singh, 2002)". 7b. Don't use latin abbreviations. That is, say "that is" instead of "ie" or "for example" instead of "eg". I guess I don't mind Latin if it's spelled out, for example "ad hoc". But, no one seems to use "exempli gratia" (e.g.) and "id est" (i.e.), for example, because they seem unnecessary, that is, there are perfectly good English substitutes. 7c. Avoid empty sections. Some text is needed between a section title and the first subsection of the section. 7d. Capitalize names of structural items like sections, equations, figures, and tables, as in "Section 3.1". So, "next section", but "Section 6". The same rule applies to "Item 2", "Table 3", "Assumption 4", "Theorem 1.5". 7e. Don't begin a sentence with a variable or function name. It can help to put "The equation ..." in front of it first. Updated by Michael L. Littman, 2008, 2010. All rights reserved. (Littman style guide. Littman grammar rules. Littman comments. Littman usage. Littman style file.)