Question

For the same sample size, would you rather have a 95% CI [confidence interval] or a 85% CI? Why or why not?

Answer 1

A 95 % confidence interval would be preferred over 85 % confidence interval because 95 % CI will be more wider than 85 % CI . Therefore, it's more likely that it will contain the true value.  If I make a confidence interval narrower by using 85 % Confidence level with lower variability and higher sample size it just becomes precise but not accurate , the likely values cover a smaller range. If I increase the coverage by using a 95% calculation it becomes more accurate, the true value is more likely to be within the range.

Typically, you are going to need a bigger interval when you want to be 95% certain that the true value is in it, than when you only need to be 85% certain, so indeed, the more confidence you need, the broader the interval you will need to pick.

In this sense, 95% CIs are more accurate which simply means you have less doubt that you will have missed the true value.