SAT® · Reading and Writing: Expression of Ideas
Goal: Explain the Purpose of a Study
A purpose goal wants the question the researchers were trying to answer, not how they ran the study or what they found. Look for the bullet phrased as something the team wanted to know.
Every set of notes on a study mixes three things: why the researchers started, what they did, and what turned up. A purpose sentence only wants the first one. That bullet usually sounds like 'researchers wanted to know' or 'suspected' or 'wondered whether' something was true. Everything else in the notes, sample size, duration, instruments, published results, exists to support that question but doesn't replace it.
Mechanically, scan the bullets and sort them in your head: which one is the question, which ones are method (sample, timeframe, tools), and which one is the outcome (numbers, percentages, what was published). Purpose sentences almost always open with an infinitive phrase of intent: 'to determine whether,' 'to test whether,' 'to find out how.' After that opener, the rest of the sentence should restate the research question in your own words, not the number that came out of it. A sentence that reports the finding, 'chloride rose to 18 milligrams per litre,' answers a different goal: result, not purpose. That's the trap: a true, well-supported sentence can still fail the goal if it answers the wrong question.
This goal sits right next to the other note-based goals on the same block: explain a result, make a comparison, or describe a method. The skill transfers directly: first identify which goal the question asks for, then hunt through the same stack of bullets for the one piece built for that job. Once you can sort notes into question, method, and outcome, every version of this goal becomes a matter of picking the right pile.
Key terms
- Purpose
- The question or suspicion that made the researchers start the study, stated before any data came in.
- Infinitive opener
- A 'to + verb' phrase like 'to determine' or 'to test' that signals intent at the start of a purpose sentence.
- Method
- The notes describing how the study was carried out, such as sample size, tools, or duration.
- Result
- The outcome or data the study produced, which explains what was found rather than why the study happened.
Watch it explained
- How it worksHow do you separate a study's aim from its method and its result inside a stack of bullets?
- How it worksHow does a purpose sentence usually open with an infinitive like 'to determine' or 'to test'?
- Common mistakeWhy doesn't a sentence reporting what a team found explain why the team ran the study at all?
- Worked exampleWalk me through picking the purpose sentence when notes list a hypothesis, a sample of 40 lakes, and a final reading.
Check yourself
End of topic.