Are you teaching the truth about paragraphs? Probably not. The truth is not what you think it is. Much of what you have learned about paragraphs is simply not true. In 1866, Alexander Bain created a list of six paragraph rules that became the foundation of modern paragraph theory. Although Bain’s rules all make logical sense and sound great, they don’t capture the reality of real writing.
If you want to understand the truth about paragraphs, main ideas, and topic sentences, this page is critical. The statistics can be a bit confusing, but the concepts are profound. When you fully understand the information presented here, you will never view paragraphs the same way again.
Let’s first establish a few terms:
1. The Main Idea of a Paragraph: A main idea answers this question: What’s your point? The good news is that most intelligible paragraphs have a main idea or make a point. Some poorly written paragraphs may not make a point.
2. Topic Sentence: A topic sentence is the main idea or main point stated in a single sentence.
3. Topic Sentence Location: Bain’s paragraph theory holds that the topic sentence should be placed first in a paragraph for emphasis.
The standard paragraph rules are not exactly true in real writing. We should all know that because we all read books, newspapers, and magazines, etc. We only need to open up a handful of professionally written texts to see that most paragraphs don’t start with a topic sentence that explicitly states the main idea. It’s not your imagination—they are not there!
The Research on Topic Sentences and Main Ideas in Professionally Written Expository Text
Researchers have proven what we should have known all along. Please note that the following research focused on expository text in academic journals, educational publications, and textbooks. Put simply, they examined the kinds of texts where the rules should apply if the rules do in fact exist.
We will take a close look at the research soon. However, I will summarize the findings now. The actual statistics are a bit more confusing than what I present here. In short, make sure you understand these three points before moving forward.
1. Main ideas are seldom stated in a single topic sentence (about 30-40% at most.) When they are, that sentence is rarely (about 13% of the time) the first sentence in the paragraph.
2. Main ideas are commonly broken up into two or more sentences. This means the main idea or main point is started in one sentence but completed in another.
3. Main ideas are implied over 50% of the time. This means that readers usually infer the main idea or main point. In short, readers can’t point to any one or two sentences that specifically state the main idea. Having said that, a point is still made, but it’s inferred.
When looking at the results of his study, Richard Braddock stated, “Teachers and textbook writers should exercise caution in making statements about the frequency with which contemporary professional writers use simple or even explicit topic sentences in expository paragraphs. It is abundantly clear that students should not be told that professional writers usually begin their paragraphs with topic sentences.”
Questioning Traditional Paragraph Theory
I love models. They bring order to chaos. The problem comes when we think they are reality or rules in the real world. Although they shine a light on the truth, they usually are not the complete truth.
One hundred years after Bain’s rules became fact, theorists began to question if professional writers actually followed his paragraph rules. The research has found that although the topic sentence rule is an effective writing technique and an excellent guideline, it is surprisingly rare. Before the statistical research had begun, here is what some theorists were already saying:
It is frequently said that every paragraph contains a topic sentence, stated or implied. A more accurate statement, however, is that some paragraphs have topic sentences and that others do not; for an “implied” topic sentence is one which the reader must construct for himself as a way of summarizing the paragraph in question. — Modern Rhetoric (1949; 1961) by Cleanth Brooks and Robert Penn Warren
The topic sentence (or thesis statement, as it is sometimes called) is a more or less fictitious entity. It does sometimes make an appearance… but… often it is not something written but what is meant by what has been written. That is, the topic sentence is something a reader extracts from a paragraph and something a writer has in mind as the unity he wants to achieve. The schoolboy notion of a topic sentence as the big firecracker, from which a string of little firecrackers is ignited, has little relationship to the truth. — The Logic and Rhetoric of Exposition 3rd Edition (1957; 1969) by Harold C. Martin, et al.
First, we teach the “methods of development…” Second, we teach the paragraph… Third, we teach what I’ll call “fixed forms…” These three approaches cover most of what most of us do to teach arrangement. They share several characteristics. They are mechanical, in the sense that they provide slots to be filled with meaning; they are idealizations, corresponding to nothing in the actual print world. They are inversions (even perversions) of the natural writing process of skilled professionals. Finally, they are artificial. — Teaching Arrangement: A Pedagogy (1979) by Patrick Hartwell
As a new teacher, I sensed that something was wrong with everything I taught my students about main ideas, topic sentences, supporting details, and paragraphs. It all made sense to me logically, but it didn’t seem to create the results it should have if it were true.
If I had been knowledgeable enough to look at the printed books, magazines, and newspapers around me, I would have seen that what I was teaching my students wasn’t true in real writing. It all sounded so logical that I couldn’t see a different way.
Still, I became a highly effective writing teacher over the next few years. To be clear, I was never satisfied with anything I taught about paragraphs. Then, one day, I was put in charge of an out-of-control class for six weeks. In this extreme situation where it was difficult to explain anything, I ended up creating Pattern Based Writing: Quick & Easy Essay. Without a doubt, Pattern Based Writing: Quick & Easy Essay is the fastest, most effective way to teach students clear and organized multi-paragraph writing… Guaranteed! Be sure to check it out.
In the following study, Richard Braddock reveals what I suspected all along.
The Frequency and Placement of Topic Sentences in Expository Prose (1974) by Richard Braddock
Richard Braddock seems to get the lion’s share of the credit for blowing the whistle on the topic sentence myth. Anyone who does even a little research into topic sentences and main ideas comes across Braddock’s research.
First, Braddock created an excellent title. It captures the main concepts we teach students about topic sentences: frequency and placement. Additionally, Braddock makes a strong point. What’s his point? In short, the frequency and placement of topic sentences in professionally written expository text does not match the long-standing rules that many textbooks and teachers teach students.
Let’s clarify another set of terms.
- Main Idea Topic Sentence / Simple Topic Sentence / The Traditional Topic Sentence: These three terms all mean the same thing.
Before we look at the statistical results of Braddock’s study, let’s consider what frequency and placement of topic sentences mean:
1. Frequency: What percentage of the time are traditional “Main Idea Topic Sentences” found in paragraphs? What percentage of the time are main ideas stated or communicated another way?
2. Placement: Where are “Main Idea Topic Sentences” placed in paragraphs? Are they put at the beginning, middle, or ending of paragraphs? What percentage of the time? What percentage of the time is the “Main Idea Topic Sentence” the first sentence of a paragraph?
Here is what Braddock found:
1. Frequency: Braddock (1974) found that 30% of contemporary, professionally-written expository paragraphs have an explicitly stated “Main Idea Topic Sentence” and 70% don’t. In other words, with 70% of paragraphs, readers must construct the main idea in their minds to some degree.
2. Placement: Braddock (1974) found that only “13% of the expository paragraphs of contemporary professional writers begin with a topic sentence, that only 3% end with a topic sentence.”
These results shred standard teaching practices. Will other researchers confirm or deny the results? In a moment, we will take a look at another study. But first, let’s put this study in perspective.
A Little Review and Perspective
Every decent paragraph with decent unity has a main idea—it makes a point of some kind that a skilled reader can visually identify or infer. There is no main idea in a paragraph with terrible unity because the ideas don’t add up to something specific. A reader is left wondering, “What is the writer trying to say? Why did the writer say this? What’s the writer’s point?”
We can assume that professional writers with professional editors create paragraphs that have decent unity and a main idea. In Braddock’s study and our following study, the researchers identified two main categories of main ideas:
1. The Main Idea is Explicitly Stated: The main idea is explicitly stated in one of two ways: a) Simple Topic Sentence or b) Delayed-Completion Topic Sentence.
2. The Main Idea is Implied: The main idea is not explicitly stated. It’s implied. The reader must infer, figure out, or construct the main idea from the entirety of the paragraph.
Keep this in mind as we examine the results of our next study.
The Frequency and Placement of Main Ideas in Children’s Social Studies Textbooks: A Modified Replication of Braddock’s Research on Topic Sentences (1984) by James F. Baumann and Judith K. Serra
As indicated in the study’s title, this study is “a modified replication of Braddock’s research on topic sentences.” Whereas Braddock’s study examined expository paragraphs written for adult readers, this study examined passages and paragraphs from elementary and middle school social studies textbooks (grades 2, 4, 6, and 8) from five different publishers.
Here are the results:
“Results were generally consistent with Braddock’s findings on topic sentences: only 44% of all paragraphs contained explicit main ideas; and only 27% of all paragraphs opened with a directly-stated main idea.”
Of the 44% of all paragraphs that did contain explicit main ideas, here is where they were located:
“Overall, 62% of the simple paragraph main ideas were stated in the first sentence, 25% appeared somewhere in the middle of the paragraph, and 13% were found in the last sentence of the paragraph.”
This study used elementary and middle school social studies textbooks. Does what you teach your students about topic sentences and paragraphs match what they see when they open up their textbooks?
One of the big breakthroughs with Pattern Based Writing: Quick & Easy Essay was that I stopped explaining concepts that just weren’t true. Basically, I said, “Just do this…” Suddenly, students knew how it felt to make a point, indent, and then make another point. They quickly became natural and organized paragraph and multi-paragraph writers and literally said, “I get it! I finally get it!”
Understanding the Studies’ Four Ways of Constructing Topic Sentences and Main Ideas
Although Braddock (1974) used the term Topic Sentence, and Baumann (1984) used the term Main Idea, they were talking about the same thing. The two studies used two main categories of topic sentences or main ideas: 1) explicitly stated and 2) implied. These two categories were divided into a total of four categories.
Traditionally, teachers teach students that topic sentences are explicitly stated in a single sentence. Most teachers understand only one type of topic sentence—the Simple Topic Sentence. In this section, you will learn four ways that professional writers construct topic sentences or communicate main ideas. Keep this in mind as we move forward:
1. Main Ideas: Every decent paragraph has a main idea. If a paragraph does not have a main idea, it’s a terrible paragraph and should be edited or removed. Main ideas can be (1) stated explicitly or (2) implied.
2. Topic Sentences: Although topic sentences are far less common than we are told, they are still important and valuable and bring clarity to writing.
This table brings the two studies together and compares the results. As you can see, both studies show that readers infer the main idea from paragraphs more than half the time.
Braddock (1974) Topic Sentence Type |
Baumann (1984) Main Idea Type |
Explicitly Stated = 30%1. Simple Topic Sentence Implied = 70%3. Assembled Topic Sentence |
Explicitly Stated = 44%1. Simple Main Idea Implied = 56%3. Inferred Main Idea |
Baumann (1984) saw Braddock’s #3-4 to be more or less the same thing, so he omitted the “assembled” category. As a teacher, I like the assembled category because it sheds light on how readers draw inferences. When readers draw inferences, they are constructing or assembling the meaning.
Here are the four types of main ideas in list form. #1 and #2 are explicitly stated. #3 and #4 are implied.
- Simple Topic Sentence: States the Main Idea in a Single Sentence
- Delayed-Completion Topic Sentence: States the Main Idea Over Two Sentences
- Assembled Main Idea: The Reader Assembles/Infers the Main Idea
- Inferred Main Idea: The Reader Infers the Main Idea
Let’s take a closer look at those four types of topic sentences and main ideas.
1. Simple Topic Sentence: The main idea is stated clearly in a single “Main Idea Topic Sentence.” To express the paragraph’s main idea, a reader can identify and quote the writer’s exact words (more or less) from a single sentence. Theoretically, this sentence should be the first sentence in a paragraph, but we sometimes find it at the end of the paragraph or somewhere in the middle.
2. Delayed-Completion Topic Sentence: The main idea begins in one sentence and is completed in a different sentence. Although the reader must piece together the main idea from two sentences, it is still clear. In short, a reader can quote the writer’s exact words (more or less) to identify the main idea. This is not a traditional “Main Idea Topic Sentence.”
3. Assembled Main Idea: The main idea is stated over multiple sentences in the paragraph. Technically, a reader can quote the writer’s exact words to state the main idea, but it won’t be easy. The reader is more likely to infer the main idea than assemble it.
4. Inferred Main Idea: The main idea is implied and cannot be directly quoted from the paragraph. We can think of a main idea as a TOPIC + CONTROLLING IDEA. To identify the main idea, a reader must first identify the topic. In short, what is the topic of the paragraph? The reader must now ask, “What do all of the sentences together say or discuss about the topic? What point has the author attempted to make about the topic?” The reader must be a deep-thinking detective and infer the main idea.
A Final Note: Don’t Be Fooled by Important and Interesting Details
The main idea is not the most important, interesting, shocking, thrilling, or powerful DETAIL. When no explicit topic sentence exists, one detail will stand out as the most important or interesting. Readers may focus on that detail and think, “This is the topic sentence!” However, it may not be. It may be that it’s just a great detail that caught our attention. The reader must ask, “Are all of the other sentences in this paragraph details or support for this one sentence? Is everything else all about that one sentence?”
The most important concept in all of reading and writing is this: What’s the point? Remember, readers often must infer the points being made. “What’s the point?” is the true essence of reading comprehension. There is a big difference between understanding and memorizing facts and comprehending the points being made. The fact that something is important or interesting does not mean that it is the point the writer is trying to make. Grasping and comprehending main ideas or main points is essential for reading comprehension. Sometimes paragraphs have a topic sentence—but often they don’t.
Writers should probably try to make their points clearer more often. Readers can only infer so much. One way to make points clear is to state them in a topic sentence. What’s a topic sentence? It states your point!
