A question about a study tests what you can conclude from its groups and results. Read what the researchers wanted to test, then pair each group with what happened to it. With several groups, ask what changed and what stayed the same, because a factor shared by all groups can't explain a difference. Predict a limited conclusion that covers both similar and different results. Wrong choices often turn a limited result into a claim the study never tested.
Hints
- Hint 1
Look at the result for each sound condition. Which conditions increased leaf area compared with silence?
- Hint 2
Compare the English, nonsense-syllable, and wind-noise results. What do their similarities and differences tell you about the question in the opening sentence?
Step-by-step
Compare the sound conditions
Step 1Name the sound conditions
The opening asks whether any benefit comes from what is said or from the sound itself, so we need to separate meaning from sound. What did the researchers vary? They compared silence, English speech, nonsense syllables, and wind recordings while keeping the cuttings, light, and watering alike. That lets us compare sounds without blaming the growing conditions.
- Step 2
Test whether meaning was needed
Does word meaning explain the extra growth? English carried meaning, but the nonsense syllables did not, and the recordings used the same tone and pacing. Both groups showed similar increases in total leaf area compared with silence, which means meaningful words weren't needed for the benefit. We can predict a role for the sound of speech, but we can't yet say which sound quality helped.
- Step 3
Check what wind noise shows
What does wind noise add to the comparison? Its plants did not differ from the silent group, although all recordings had the same average volume. So not every recorded sound produced the benefit. Since volume was shared by all three recordings, the extra growth points to sound qualities of speech rather than volume alone.
- Step 4
Match the limited conclusion
Which wording captures that limited prediction? The phrase some acoustic features typical of human speech names sound qualities shared by speech recordings, while not word meaning separates those qualities from meaningful words. The word may allows a possible benefit, not a guarantee. Choice A.