A question about whether a program caused a score difference is about causation, not calculation. Look for random assignment: if chance chose which schools used the program, the score difference can support cause rather than association alone. Then keep the conclusion within the district and grade studied, and describe an average rather than every student's score.
Hints
- Hint 1
In a randomized experiment, chance decides which group receives the program. Here, chance chose schools, not individual students. What does that let you say about the cause of a difference between the groups?
- Hint 2
The schools that kept their usual curriculum form a comparison group: they show what happened over the same year without the new program. What did the same assessment show about the two groups?
- Hint 3
Keep the conclusion within this district's 4th graders. The finding compares averages; it doesn't say every student improved. Were other districts or grades included?
Step-by-step
Check assignment, comparison, and scope
Step 1Use the random assignment to judge cause
No Desmos needed. The question asks what the study design supports, not for a calculation. The researcher chose of the schools at random to use the program; the other did not. This is random assignment: chance, rather than the schools' choices, decided who got the program. Random assignment lets a difference in group averages support cause, not just association.
- Step 2
Identify what the program was compared with
The other schools kept their usual reading curriculum, so they form a comparison group: a baseline for what happened over the same year without the new program. The program schools scored significantly higher on the same assessment, supporting an effect compared with usual instruction.
- Step 3
Keep the conclusion within the studied group
The district has exactly elementary schools, and all were included. Every district 4th grader took the assessment, so the studied population is this district's 4th-grade students. No other districts or grades were tested, so a statewide or nationwide claim goes too far.
- Step 4
Match the conclusion to the average
The finding compares average scores; it doesn't show that every student's score improved. So the new reading program caused a higher average reading score for 4th-grade students in this school district. Choice C.