Editing a Lab Report Conclusion on Plant Growth
A student writes a conclusion for a lab report: 'In this experiment, we tested how light color affects plant growth. Ten bean plants were placed under red light, ten under blue light, and ten under white light. After three weeks, the average height under red light was 14.2 cm, under blue light 11.8 cm, and under white light 13.5 cm. The plants under red light grew the tallest, so red light is the best for all plants. It was also observed that the blue-light plants looked less green. The data shows that light color affects growth, but the difference between red and white is small. More trials are needed before recommending red light to farmers.' The teacher asks the student to revise the conclusion for precision, consistent verb tense, and clear pronoun reference. The report must not overgeneralize beyond the data.
1. Identify one sentence that overgeneralizes and revise it to match the data. Explain what the original claims beyond the evidence.
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The sentence 'The plants under red light grew the tallest, so red light is the best for all plants' overgeneralizes. The data come from 30 bean plants in one experiment over three weeks, with average heights of 14.2 cm under red, 13.5 cm under white, and 11.8 cm under blue. The original says 'best for all plants,' which goes far beyond bean plants and beyond the measured outcome of height. It also uses 'best' without saying best for what. A precise revision is: 'The plants under red light had the greatest average height in this experiment, but the difference between red and white light was small.' This keeps the result, limits the claim to the sample, and acknowledges the modest gap.
2. Revise the sentence 'It was also observed that the blue-light plants looked less green.' Address the unclear pronoun and the voice.
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Revision: 'We also observed that the blue-light plants appeared less green.' The original 'It was also observed' uses an expletive 'It' that has no clear referent and hides who made the observation. The passive voice is not wrong in all lab reports, but here it makes the sentence vague. Using 'We also observed' supplies a clear subject and matches the first-person voice already used in 'we tested.' Changing 'looked' to 'appeared' is slightly more formal and precise for a lab report. The revision still reports the same observation without claiming that blue light caused the color difference.
3. Explain how the final sentence 'More trials are needed before recommending red light to farmers' functions in the conclusion.
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The final sentence functions as a limitation and a caution. It acknowledges that one experiment with 30 bean plants is not enough to justify a recommendation to farmers, especially when the red-versus-white difference is only 0.7 cm on average. It also signals that replication is needed before applying the result beyond the sample. Without this sentence, the conclusion would move too quickly from a single lab result to an agricultural recommendation. The sentence does not weaken the report; it makes the report more credible because it distinguishes what the data show from what farmers should do. It also matches the teacher's requirement not to overgeneralize.