Question 137·Medium·Central Ideas and Details
Across the world, ordinary volunteers are helping professional researchers collect data on everything from migratory birds to rainfall patterns. These citizen scientists may not have formal training, but their contributions, enabled by smartphone apps and online databases, now account for a significant share of observations in many fields.
Which choice best states the main idea of the text?
For main idea questions, first read the entire passage and then briefly summarize it in your own words without looking at the choices. Next, eliminate any answer that introduces new information (like motives, opinions, or results) that the text never mentions, or that is too narrow (only one detail) or too extreme (words like "most," "always," or "replace" if the passage doesn’t clearly support them). Finally, choose the option that best matches your summary and the overall focus of the passage, not just a single sentence or phrase.
Hints
Focus on the whole paragraph
Ask yourself: If I had to explain this entire paragraph in one sentence to a friend, what would I say? Don’t get stuck on just one phrase or detail.
Pay attention to the second sentence
The second sentence explains the impact of citizen scientists’ contributions. How does it describe the amount or importance of the data they provide?
Watch out for extra ideas
Look for answer choices that add things the passage never mentions, such as people’s motivations, negative opinions, or scientists being replaced. Those are usually wrong for main idea questions.
Step-by-step Explanation
Identify the general topic
Read the passage and ask: Who is being discussed, and what are they doing?
The passage talks about "ordinary volunteers" and "citizen scientists" who are working with professional researchers. It also mentions what they help collect: data on birds, rainfall, and more.
Restate the main point in your own words
Combine the key pieces:
- They are ordinary volunteers without formal training.
- They use tools like smartphone apps and online databases.
- Their contributions "now account for a significant share of observations in many fields."
In your own words, the paragraph is saying that volunteers who aren’t professional scientists are now providing a lot of useful data for scientific research.
Eliminate choices that add ideas not in the text
Check each option against the passage:
- Does the passage say professional scientists are being replaced?
- Does it give a reason why most volunteers join?
- Does it say scientists are skeptical of this data?
If an answer introduces one of these ideas, it goes beyond what the passage says and should be eliminated.
Match the remaining choice to your summary
After removing choices that mention replacement of scientists, motives of volunteers, or skepticism, the remaining choice is the one that matches your own summary: Participation of non-scientists has become an important source of data for scientific research. This directly reflects that volunteers’ contributions now make up "a significant share of observations in many fields."