Question

If observations are not randomly sampled and independent of one another, what happens in ANCOVA?

a.

Exact results

b.

Inaccurate results

c.

Increased risk of error

d.

The sample size must be increased.

Answer 1

When the observations are not randomly sampled and independent of one another, then the ANCOVA test gives us inaccurate result because independence between observations and normal data distribution are two key assumptions in ANCOVA test.

Therefore, option B is correct answer

option A is incorrect because we can never get exact results with and without independence.

option C is incorrect because risk of error will not increase because the risk of error is measured when assumptions are met

option D is incorrect because non random sampling and dependency can never be corrected due to large sample size.