Scientific Reading Comprehension Flashcards

A passage describes a cohort study following 500 optometry students over 10 years to track myopia progression. The key feature that distinguishes a cohort study from a case-control study is:

Answer: Participants are selected based on exposure status and followed forward in time for outcomes

Cohort studies select based on exposure and follow subjects prospectively, whereas case-control studies start with disease status and look backward.

A table in a passage shows mean visual acuity values with standard deviations for four age groups. The standard deviation is best interpreted as:

Answer: A measure of spread indicating how much individual values vary around the mean

Standard deviation quantifies variability of individual data points around the group mean.

A passage introduces a newly coined term 'photoreceptor fatigue index' and defines it in the first paragraph. In subsequent paragraphs, when the author uses this term, the reader should:

Answer: Apply the specific definition provided in the passage, not outside knowledge

When a passage defines a technical term, that definition governs its use throughout the passage, regardless of external knowledge.

A passage reports: 'Treatment A reduced cup-to-disc ratio by 0.05, while Treatment B reduced it by 0.04 (p = 0.12 for comparison).' The most accurate conclusion is:

Answer: The difference between treatments A and B is not statistically significant

p = 0.12 exceeds the conventional α = 0.05 threshold, meaning the observed difference could plausibly occur by chance.

In a passage discussing corneal topography research, the authors state their findings 'may not generalize to pediatric populations.' This caveat addresses which aspect of the study?

Answer: External validity (generalizability)

External validity concerns whether results can be generalized to populations beyond the study sample.

A passage presents a bar graph with error bars representing standard error of the mean (SEM). Overlapping error bars between two groups most likely indicate:

Answer: The difference between group means may not be statistically significant

Overlapping SEM bars suggest that difference between means may not reach statistical significance, though formal testing is required.

A passage describes an experiment where a confounding variable was controlled using 'stratified randomization by age.' The purpose of this technique is to:

Answer: Ensure age is evenly distributed across treatment groups so it cannot explain outcome differences

Stratified randomization balances potential confounders like age across groups, preventing them from distorting treatment comparisons.