When you're reading for the main idea on a standardized test like the ACT, SAT or your English test in school, the good news is that you'll have answer choices to select from! You won't have to write the main idea yourself. The bad news is that you have answer choices! What? Answer choices are good and bad? Yes. Answer choices can lead you toward making common main idea mistakes, but you can teach yourself how to avoid them with practice!
Main Idea Mistake #1: Choosing an Answer That's Too Narrow
Let's say you read a passage about Leonardo da Vinci's genius. Several paragraphs talk about his sculpting, charcoal drawings, and paintings. Other paragraphs mention his science skills and foresight into mechanical engineering. If you select an answer that only details his sculpting, drawings and paintings, then your choice is too narrow: it only uses part of the information from the passage.
How to Avoid the "Too Narrow" Mistake: Be sure to choose an answer that encompasses every major idea in the passage, not just a few.
Main Idea Mistake #2: Choosing an Answer That's Too Broad
Suppose the next passage you read on your test is a summary of a Blue Angels' performance last May. The passage explains the maneuvers, tricks and near-misses that happened that day. It showcases the daredevil approach of the newest pilot on the team, and congratulates the veterans on their mastery of the techniques that woo the crowd. If you select an answer that mentions how to become a Blue Angel, then your choice is too broad: it goes beyond the scope of the passage and gives information not discussed.
How to Avoid the "Too Broad" Mistake: Choose an answer that doesn't step outside the passage. If you can't find the idea or infer the idea from the info in the passage itself, then it is not the correct choice.
Main Idea Mistake #3: Choosing an Answer That's Complex, But Opposite
The third passage you read on your exam argues that the haiku is a better poetic form than the tanka. The author explains each ancient Chinese poetic form and describes how the tanka has changed throughout centuries to fit into a modern-day approach, while the haiku has remained intact, which is more noble. While explaining the length of lines, syllables, and format required, the author gives poems from each to demonstrate how superior the haiku is over the tanka. Be careful not to select an answer that sounds really good, because of the length of lines and similarity to the passage, but actually states that the tanka is better than the haiku! Writer's often slip the opposite meaning into an answer choice to check your reading comprehension.
How to Avoid the "Complex, But Opposite" Mistake: Read the answer choices carefully. Do NOT choose an answer because it merely "sounds" right. Put the answer choices in your own words so you can dissect the meaning better. You must choose the choice that actually reflects the main idea, not the opposite.