answersLogoWhite

0


Best Answer

A one-tailed test should be used only in a study in which an effect in the unexpected direction is functionally equivalent to no effect. It is not appropriate to use a one-tailed test simply because one is able to specify the expected direction of the effect prior to running the study. In medicine, for example, we typically expect that the new procedure will improve the cure rate, but a finding that it decreases the cure rate would still be important, since it would demonstrate a possible flaw in the underlying theory. For a given effect size, sample size, and alpha, a one-tailed test is more powerful than a two-tailed test (a one-tailed test with alpha set at .05 has approximately the same power as a two-tailed test with alpha set at .10). However, the number of tails should be set based on the substantive issue (will an effect in the reverse direction be meaningful).

User Avatar

Wiki User

16y ago
This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: When is it valid to use a one-tailed test?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Related questions

A test may be reliable but not necessarily validIs it possible for a test to be valid but not reliable?

No, for a test to be valid, it must also be reliable. Reliability refers to the consistency of the test results, while validity refers to the accuracy of the test in measuring what it is supposed to measure. A test cannot be valid if it is not reliable.


Is a reliable test necessarily valid?

In my view reliable test is always valid.


Who Questions that test if your gay or straight?

There is no such valid test, so I would definitely question it.


Can an unreliable test be valid?

No


What is test validity?

If you are testing a hypothesis, does the test have anything to do with the hypothesis. If I want to test something to do with gravity and I use a red object compared to a blue object that probably isn't valid.


Is a HIV test done at 85 day after the intercourse and the result is negative is that result is valid?

Yes, it would be a valid test.


Is there a valid online intelligence test?

No


What is the difference between a valid test and a reliable test?

Reliable indicates that each time the experiment is conducted, the same results are obtained (accuracy). Valid indicates the experiment (or test) has controlled variables and used an appropriate method/model.


Does online ability test valid?

Yes sure. It is valid. It will shows the how fast you are thinking.


Is my Lowes coupon code still valid?

You will have to try it out. Go to the Lowes website and test it out. If you punch the code in and it is accepted then you will be able to use it.


What is an example of a valid test?

LSAT, MCAT, so on


What is an experimental test done more than once?

To ensure that the results are valid. That's the whole point of a science test. The test must be able to be repeated and have the same result to start being considered valid.