OAT Scientific Reading Comprehension 2

Question 1

A passage states: 'The researchers found a statistically significant inverse correlation (r = -0.78, p < 0.01) between intraocular pressure and retinal ganglion cell density.' What does this mean?

Accepted Answer

Higher IOP is associated with lower ganglion cell density

Answer

An inverse correlation means as one variable increases the other decreases, so higher IOP is associated with lower RGC density.

Question 2

A study abstract reports a 95% confidence interval of [2.1, 4.3] mmHg for mean IOP reduction. Which conclusion is most appropriate?

Accepted Answer

There is 95% probability the true mean reduction is between 2.1 and 4.3 mmHg

Answer

A 95% CI means we are 95% confident the true population mean lies within that interval.

Question 3

A passage describes a double-blind randomized controlled trial comparing two contact lens solutions. The primary advantage of double-blinding in this context is:

Accepted Answer

Neither subjects nor evaluators know which solution is being tested, reducing bias

Answer

Double-blinding prevents both participants and assessors from knowing treatment assignments, minimizing placebo and observer bias.

Question 4

A graph in a passage shows corneal thickness (y-axis) plotted against age (x-axis) with a shallow negative slope. The most accurate interpretation is:

Accepted Answer

Corneal thickness tends to decrease slightly as age increases

Answer

A negative slope indicates an inverse trend, but scatter means individual values vary; correlation does not imply causation.

Question 5

A research passage uses the term 'sensitivity' in the context of a diagnostic test for diabetic retinopathy. Sensitivity refers to:

Accepted Answer

The test's ability to correctly identify patients who have the disease

Answer

Sensitivity (true positive rate) measures how well a test detects disease among those who actually have it.

OAT - Optometry Admission Test Practice Test

OAT - Optometry Admission Test Practice Test

OAT Scientific Reading Comprehension 2