1. Topic Sentences, Main Ideas and Specific Details
Main Ideas describe the topic.
Specific Details explain it.

2. A Supporting Details supports the main idea.
A Main Idea states the topic/subject and purpose.
A Supporting Details supports the main idea.

3. The first sentence is about similarities, but the paragraph is about differences!
Porpoises and dolphins are so similar in general appearance that many people mistake one for the other. However, they possess distinct differences. One difference is their shape. Porpoises are smaller and plumper than dolphins, which have long, streamlined bodies. In addition, the porpoise has a rounded head and a blunt snout in contrast to the dolphin’s beak-like nose. A second difference can be seen in their sizes. Porpoises rarely grow to be more than six feet in length or weigh more than 300 pounds. In contrast, dolphins can be four to twenty-six feet long and weigh from 70 to 1,500 pounds. Therefore, isn’t it weird that people mistake one for the other?
Is the word
‘however’
often
a clue
to the
topic?

4. Since the topic is about differences, the major details (supports the main idea) must describe them.
Porpoises and dolphins are so similar in general appearance that many people mistake one for the other. However, they possess distinct differences. One difference is their shape. Porpoises are smaller and plumper than dolphins, which have long, streamlined bodies. In addition, the porpoise has a rounded head and a blunt snout in contrast to the dolphin’s beak-like nose. A second difference can be seen in their sizes. Porpoises rarely grow to be more than six feet in length or weigh more than 300 pounds. In contrast, dolphins can be four to twenty-six feet long and weigh from 70 to 1,500 pounds. Therefore, isn’t it weird that people mistake one for the other?

5. Then minor details (supports the major details) must explain differences.
Porpoises and dolphins are so similar in general appearance that many people mistake one for the other. However, they possess distinct differences. One difference is their shape. Porpoises are smaller and plumper than dolphins, which have long, streamlined bodies. In addition, the porpoise has a rounded head and a blunt snout in contrast to the dolphin’s beak-like nose. A second difference can be seen in their sizes. Porpoises rarely grow to be more than six feet in length or weigh more than 300 pounds. In contrast, dolphins can be four to twenty-six feet long and weigh from 70 to 1,500 pounds.

6. What is the topic sentence?
1 What causes reading disabilities, or dyslexia? 2Studies have been conducted for generations in an attempt to find answers to this difficult question. 3Rather than a single answer, however, several factors have emerged which seem to contribute to the disability. 4One factor points to a genetic link from one generation to the next. 5In particular, males are more likely to be affected if a father, grandfather, or uncle had dyslexia. 6Early difficulty in discriminating sounds appears to be another factor. 7Children who cannot hear the subtle differences within and among words will also have difficulty in reading those sounds. 8Finally, visual-perceptual problems, a difficulty in clearly seeing the written words, also contribute to dyslexia. 9If the words do not appear clearly, seem to move, or create distortions, the reader will not be able to read fluidly and comprehension will suffer.

7. Main idea/Topic is in the middle.
1What causes reading disabilities, or dyslexia? 2Studies have been conducted for generations in an attempt to find answers to this difficult question. 3Rather than a single answer, however, several factors have emerged which seem to contribute to the disability. 4One factor points to a genetic link from one generation to the next. 5In particular, males are more likely to be affected if a father, grandfather, or uncle had dyslexia. 6Early difficulty in discriminating sounds appears to be another factor. 7Children who cannot hear the subtle differences within and among words will also have difficulty in reading those sounds. 8Finally, visual-perceptual problems, a difficulty in clearly seeing the written words, also contribute to dyslexia. 9If the words do not appear clearly, seem to move, or create distortions, the reader will not be able to read fluidly and comprehension will suffer.
The 1st
sentence
as a question can’t be the main idea. It is the hook!
The 3rd sentence uses the key phrase
“several factors” to explain the topic.
The 2nd
sentence
only says
that there are
studies on the topic.

8. What are the major details?
1What causes reading disabilities, or dyslexia? 2Studies have been conducted for generations in an attempt to find answers to this difficult question. 3Rather than a single answer, however, several factors have emerged which seem to contribute to the disability. 4 One factor points to a genetic link from one generation to the next. 5In particular, males are more likely to be affected if a father, grandfather, or uncle had dyslexia. 6Early difficulty in discriminating sounds appears to be another factor. 7Children who cannot hear the subtle differences within and among words will also have difficulty in reading those sounds. 8 Finally, visual-perceptual problems, a difficulty in clearly seeing the written words, also contribute to dyslexia. 9If the words do not appear clearly, seem to move, or create distortions, the reader will not be able to read fluidly and comprehension will suffer.
Do you notice any TRANSITION words?
Since the topic sentence asserts that there are several factors, the major details must describe the factors.

9. Where are the minor details?
1 What causes reading disabilities, or dyslexia? 2 Studies have been conducted for generations in an attempt to find answers to this difficult question. 3 Rather than a single answer, however, several factors have emerged which seem to contribute to the disability. 4 One factor points to a genetic link from one generation to the next. 5 In particular, males are more likely to be affected if a father, grandfather, or uncle had dyslexia. 6 Early difficulty in discriminating sounds appears to be another factor. 7 Children who cannot hear the subtle differences within and among words will also have difficulty in reading those sounds. 8 Finally, visual-perceptual problems, a difficulty in clearly seeing the written words, also contribute to dyslexia. 9 If the words do not appear clearly, seem to move, or create distortions, the reader will not be able to read fluidly and comprehension will suffer. Therefore, isn’t it weird that people mistake one for the other?
Since the major details describe the factors,
the minor details must explain the factors.

10. The Paragraph Outlined
Topic Sentence: Rather than a single answer, however, several factors have emerged which seem to contribute to the disability.
A. Main Idea #1 : One factor points to a genetic link from one generation to the next.
i, Main Idea #1: In particular, males are more likely to be affected if a father, grandfather, or uncle had dyslexia.
B. Main Idea #2: Early difficulty in discriminating sounds appears to be another factor.
ii. Main Idea #2: Children who cannot hear the subtle differences within and among words will also have difficulty in reading those sounds.
C. Main Idea #3 : Finally, visual-perceptual problems, a difficulty in clearly seeing the written words, also contribute to dyslexia.
iii. Main Idea #3: If the words do not appear clearly, seem to move, or create distortions, the reader will not be able to read fluidly and comprehension will suffer.

11. What is the Topic Sentence?
Making instinctive decisions can be better than thinking through options, according to psychologist Li Zhao-ping. Study participants were shown a computer screen with more than 650 identical symbols and asked to identify on which side of the screen an inverted symbol appeared. Li and colleagues found that when the participants were given a fraction of a second to look at the screen, they gave the correct answer 95 percent of the time. However, when given longer, they were only 70 percent accurate. The conscious brain blocks our initial subconscious decision even when it is correct, leaving us unaware or distrustful of our instincts and disadvantaged. The subconscious is more useful when you don't have time and need to react quickly. Your body is designed to do some things very quickly, so using instincts is better there.

12. What is the Topic Sentence?
Making instinctive decisions can be better than thinking through options, according to psychologist Li Zhao-ping. Study participants were shown a computer screen with more than 650 identical symbols and asked to identify on which side of the screen an inverted symbol appeared. Li and colleagues found that when the participants were given a fraction of a second to look at the screen, they gave the correct answer 95 percent of the time. However, when given longer, they were only 70 percent accurate. The conscious brain blocks our initial subconscious decision even when it is correct, leaving us unaware or distrustful of our instincts and disadvantaged. The subconscious is more useful when you don't have time and need to react quickly. Your body is designed to do some things very quickly, so using instincts is better there.
What are the Main Ideas?

13. What is the Topic Sentence?
Making instinctive decisions can be better than thinking through options, according to psychologist Li Zhao-ping. Study participants were shown a computer screen with more than 650 identical symbols and asked to identify on which side of the screen an inverted symbol appeared. Li and colleagues found that when the participants were given a fraction of a second to look at the screen, they gave the correct answer 95 percent of the time. However, when given longer, they were only 70 percent accurate. The conscious brain blocks our initial subconscious decision even when it is correct, leaving us unaware or distrustful of our instincts and disadvantaged. The subconscious is more useful when you don't have time and need to react quickly. Your body is designed to do some things very quickly, so using instincts is better there.
What are the Supporting Details?

14. What are the Main Ideas?
The key findings describe results of the choices we make when we have time and when we don’t: the key results are the main ideas.
Making instinctive decisions can be better than thinking through options, according to psychologist Li Zhao-ping. Study participants were shown a computer screen with more than 650 identical symbols and asked to identify on which side of the screen an inverted symbol appeared. Li and colleagues found that when the participants were given a fraction of a second to look at the screen, they gave the correct answer 95 percent of the time. However, given longer they were only 70 percent right. The conscious brain blocks our initial subconscious decision even when it is correct, leaving us unaware or distrustful of our instincts and disadvantaged. The subconscious is more useful when you don't have time and need to react quickly. Your body is designed to do some things very quickly, so using instincts is better there.

15. What are the minor details?
Explain how the major details function; in this case how our fast choices can be better.
Making instinctive decisions can be better than thinking through options, according to psychologist Li Zhao-ping. Study participants were shown a computer screen with more than 650 identical symbols and asked to identify on which side of the screen an inverted symbol appeared.
Li and colleagues found that when the participants were given a fraction of a second to look at the screen, they gave the correct answer 95 percent of the time. However, given longer they were only 70 percent right.
The conscious brain blocks our initial subconscious decision even when it is correct, leaving us unaware or distrustful of our instincts and disadvantaged.
The subconscious is more useful when you don't have time and need to react quickly. Your body is designed to do some things very quickly, so using instincts is better there.

16. Review of Details
To locate supporting details, a master reader turns the TOPIC into a question.
A main idea directly describe the topic.
A supporting detail explains the major detail.
In a passage, ideas usually flow from general to specific ideas.