In this next module, we're going to move up from sentences to whole paragraphs. We'll continue discussing paragraphs into next week, and then we'll progress to whole compositions. I want you to think of the paragraph as the unit of composition of your manuscript. Each paragraph should contain one main idea. And you should think in paragraphs when you're organizing your manuscript. Scientists often try to stuff too many ideas into a single paragraph. They end up with these long paragraphs that are extremely hard to read, because they meander through so many different ideas without a clear focus. Use the paragraph to delineate to your reader when you're switching to a new idea. Your paragraphs should be short. If you pick up professional writing like a magazine, you'll notice that they might have two, three, four maybe five sentences in the paragraph. Short paragraphs are not only more focused, but they provide a lot of white space on the page. Readers appreciate white space. There's nothing worse for a reader than seeing a huge block of text with no breaks. As a reader, you know such prose is going to be tedious and hard to get through. The reader appreciates short paragraphs and white space on the page. When I'm editing students' work I often end up splitting up their paragraphs. So try to keep your paragraphs short and focused on a single idea. Another key tip on paragraphs is that you should give away the punch line early. Scientists don't think like this, scientists like to put details, details, data, supporting data, conclusion. That's the way scientists think. However, when you go to write things up, I'm going to encourage you to invert that. Give away the punchline, the conclusion, first to let the reader know where you're going. It's hard for the reader to weed through all the details first, when they don't know what the main point is. In journalism, we called this the inverted pyramid style. You start with the most important point, the take-home message, and then you filter down from there with the supporting ideas. The idea of giving away the punchline early is somewhat similar to topic sentences. I have to say though, I'm not a huge fan of topic sentences per se. I think it's confining if you feel like you have to start every paragraph with an exact statement of the aim of the paragraph. I think that becomes monotonous. So don't feel like you need to go to the extreme of writing topic sentences. But you do need to be aware of the point of your paragraph, and you do need to clue your reader into this point early on. In terms of paragraph flow, I want you to rely primarily on good logic to make your paragraphs flow well. Your reader should be able to follow you because you are leading them through your ideas in an organized and logical manner. If you use logic, you don't need to give your reader a lot of flag posts and pointers as to where you're going. You can also use parallel sentence structure to help with flow. One strategy is to give adjacent sentences a matching structure. This helps with flow, and I'm going to show you some examples in a minute. Finally, I do not want you to rely on transition words. I find that scientist greatly over use transition words. Sometimes they use a transition word to start every sentence. Many scientists reach for transition words as a crutch to make up for the fact that their underlying logic is faulty. This doesn't work, transition words aren't strong enough to fix underlying logic that's not sound. Also, don't be too exotic with your transition words. You'll notice in a lot of professional writing the favorite transition word is but, B-U-T. It's a great way to indicate to the reader that hey, I'm going to be changing gears here. You don't need fancy words like nevertheless, or on the other hand. Just use but, B-U-T. I tend to use just two transition words. But, to indicate to the reader that I'm switching modes. And and, A-N-D, to indicate that I'm tacking on some additional information. The final tip on paragraphs is, keep in mind that your reader will tend to remember the first sentence and the last sentence best. So you want to make those sentences memorable. Maybe you have a little build up to the last sentence, a little emphasis at the end. That can make a really good paragraph. In terms of a logical flow of ideas, what do I mean by that? You want your sentences to flow naturally from one to the next. For example, you should generally go sequential in time, starting from the earliest event and ending with the latest event. That's what your reader expects, it's predictable and easy to follow. I'd like to say you should avoid the approach of that movie Memento that was out in the year 2000. That had this very bizarre timeline, where things didn't go in sequential order. That's a very interesting and creative way to film a movie, but it's very hard on a reader of the scientific literature. So just go in order in time. Another way to make your writing flow logically is to start with something that's in general, and then move to the specific. Give the take-home message, the general point, and then give specific examples. Also, you can think about constructing formal logical arguments. I was a philosophy major as an undergraduate, so I took a lot of logic classes where we did if a then b, a therefore b. So I sometimes will actually outline the logical arguments that I want to make in my prose. That insures that I have sound logic that's easy for readers to follow. Just to throw in an example here, I pulled this paragraph from a paper published in Science. I'm not going to read the whole example, but you can see that one, this is an intimidating block of text. Without even reading it, you already know it's going to be hard to get through. And two, most sentences in this paragraph start with a transition word. We get furthermore, thus, however, however, thus, however. The reader is going to get whiplash with so many howevers indicating a change of course. Here's an example of a well-written paragraph. This comes from President Obama's editorial essay in Wired magazine that I mentioned in an earlier module. It says, this kind of progress hasn't happened on its own. It happened because people organized and voted for better prospects. Because leaders enacted smart, forward-looking policies; because people's perspectives opened up, and with them, societies did too. But this progress also happened because we scienced the heck out of our challenges. Science is how we were able to combat acid rain and the AIDS epidemic. Technology is what allowed us to communicate across oceans and empathize with one another when a wall came down in Berlin or a TV personality came out. Without Norman Borlaug's wheat, we could not feed the world's hungry. Without Grace Hopper's code, we might still be analyzing data with pencil and paper. I want to point out some features of this paragraph. First of all, what's the main idea of this paragraph? The main idea is that science has been integral to progress in the world. The bolded statement here, the bolded sentence, best states that idea. Another thing to point out is that only one sentence in this whole paragraph starts with a transition word. We get the word, but. Again, this is an excellent transition word to alert your reader that you're switching gears. But this is the only sentence that starts with a transition word. That the paragraph flows beautifully without relying on transition words. The paragraph flows because there is a nice build up of ideas. We go from general to specific. We go from general reasons that progress has occurred in the world, to one specific reason, science. And then we get specific examples of how science has facilitated progress in the world. There's also some beautiful parallelism here. Science is how we were able to combat acid rain and the AIDS epidemic. Technology is what allowed us to communicate across oceans and empathise with one another. These two sentences match in terms of their structure. That's poetic, and it moves the paragraph along. Similarly, we get parallelism in the last two sentences. Without Norman Borlaug's wheat, we could not feed the world's hungry. Without Grace Hopper's code, we might still be analyzing data with pencil and paper. They follow the same exact setup, which again, is very elegant.