Quantitative Evidence combines evidence reasoning with graphical literacy. The central question is not ‘What numbers are visible?’ but ‘What relationship must the data show for this claim?’
What the SAT is testing
- Command of Evidence
- A supplied claim or point is evaluated with the textual or quantitative evidence that best supports, illustrates, weakens, or challenges it.
Core concept
Identify the claim first, then the variables, categories, units, and scope. A general claim across years needs a pattern across years; one convenient point is rarely sufficient.
Evidence distinctions
Absolute change
New minus original. Example: 20 to 30 is +10
Percent change
Change divided by original. Example: 10 ÷ 20 = 50%
Percentage
A proportion out of 100. Example: 30 of 60 is 50%
Step-by-step strategy
Claim-first evidence method
- Identify
State the exact claim, including its population, condition, direction, and qualification.
- Predict
Ask what evidence would look like if the claim were true—or what would challenge it.
- Locate
Select only the text or data relevant to that predicted relationship.
- Compare
Evaluate direction, scope, directness, and required assumptions across choices.
- Verify
Check the chosen wording and every cited value against the stimulus.
Visual and data-reading strategy
| Year | Learners | Completion rate |
|---|---|---|
| Year 1 | 200 | 60% |
| Year 2 | 250 | 68% |
Worked example
Apply 3-7
A program served 200 learners in year 1 and 250 in year 2. Completion rose from 60% to 68%.
Question: Which evidence best supports the claim that both reach and completion rate increased?
- Enrollment rose by 50 learners, and completion rose by 8 percentage points.
- Enrollment rose by 25%, so completion rose by 25%.
- Completion was 68 learners in year 2.
- The program served 450 learners across both years.
- Step 1
Reach refers to learner count; completion rate refers to a percentage.
- Step 2
Compare each measure with its own baseline.
- Step 3
Do not convert 68% into a count without calculation or reuse 25% for another variable.
Why each choice works or fails
- Correct: both comparisons and units are accurate.
- Wrong comparison: the percent change in enrollment does not transfer to completion rate.
- Percentage/count confusion.
- A total erases the before-after evidence.
Common traps and wrong-answer patterns
Mini check
A value rises from 40 to 50. What are its absolute and percent increases?
- 10 and 10%
- 10 and 25%
- 25 and 10%
- 50 and 25%
Show answer and explanation
Answer: B
The absolute increase is 10; 10 ÷ 40 = 25%.
Key takeaways
What to remember
- Read the claim before the graphic.
- Match evidence scope to claim scope.
- Keep counts, percentages, and units distinct.
- Use only the simple calculation the evidence task requires.
Put these notes into practice
Apply the ideas with SAT-style questions, then reinforce key details with flashcards.