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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).
What else can I help you with?
When is it valid to use a one-tailed test?
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).
What statistical test is used to find out if there is a significant mean difference between two split groups on a dependent variable measured on an interval or ratio scale?
You could use a two-tailed t-test. You would use a two-tailed test instead of a one-tailed test because you are not hypothesizing which direction the difference will be. If you hypothesize before hand the direction of change, you could use a one-tailed test.
Is the hypothesis that men and women use the Internet approximately the same number of hours per week a one-tailed test or a two-tailed test?
Two-tailed test Hi: µM-µF = 0 Because if it turns out that Hi: µM-µF ≠0, the difference may be greater or smaller
What two critical values of t from the t-distribution would you use to have 99 percent probability -area- for accepting the null hypothesis if you had df8?
91
When to apply two tailed test in testing hypothesis?
When the alternative hypothesis is non-directional, we use a two-tailed test. Example: H0: mean = 50 Ha : mean not equal to 50 Here is a directional hypothesis that would use a one-tailed test. H0: mean = 40 Ha : mean > 40 or H0: mean = 40 Ha: mean < 40
A test may be reliable but not necessarily validIs it possible for a test to be valid but not reliable?
A test may be reliable but not valid. A test may not be valid but not reliable. For example, if I use a yard stick that is mislabeled to measure the distance from tee to hole in golf on different length holes, the results will be neither reliable nor valid. If you use the same stick to measure football fields that are the same length the result will reliable (repeatable, consistent) but not valid (wrong numbers of yards). There is no test that is unreliable (repeatable, consistent) and valid (measures what we are looking for).
Why use 2 tailed or 1 tailed?
statistic
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.
Does Naruto use the nine-tailed fox after the fight with pain?
No he does not use the nine tailed fox
Will Ultram test positive for cocaine?
No, there is only one drug with a valid use that can give a false positive for cocaine. Cocaine-hydrochloride topical solution. It is used by eye and throat surgeons as an anesthetic.
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.
How does one generally use a home pregnancy test?
First make sure you check to see if the test is valid. Then you sit on the toilet and urinate on the stick for a few seconds. You next put it flat on a dry surface and wait the prescribed amount of time to see for the results.
