Can a dependent t-test be one-tailed?

Note that when you do a paired t-test, you are testing if the mean difference between pairs is significantly different from 0. You describe a one-tailed t-test which gives you the option to test if there is a difference in one direction (e.g. ‘greater than’ in the case you describe).

What is a 1 tailed t-test?

A one-tailed test is a statistical test in which the critical area of a distribution is one-sided so that it is either greater than or less than a certain value, but not both. If the sample being tested falls into the one-sided critical area, the alternative hypothesis will be accepted instead of the null hypothesis.

What is a dependent t-test used for?

The dependent t-test can be used to test either a “change” or a “difference” in means between two related groups, but not both at the same time. Whether you are measuring a “change” or “difference” between the means of the two related groups depends on your study design.

What is an example of a dependent t-test?

For example, you could use a dependent t-test to understand whether there was a difference in smokers’ daily cigarette consumption before and after a 6 week hypnotherapy programme (i.e., your dependent variable would be “daily cigarette consumption”, and your two related groups would be the cigarette consumption values …

Are t-tests always two-tailed?

For two sided-biological hypotheses (i.e., you only care whether the means are different), you will want to use a two-tailed t-test. The null and alternative statistical hypotheses for a two-tail test are always as follows. If your hypotheses are one-sided, then you will want to use a one-tailed t-test.

What is the difference between independent t-test and dependent t-test?

Dependent samples are paired measurements for one set of items. Independent samples are measurements made on two different sets of items. When you conduct a hypothesis test using two random samples, you must choose the type of test based on whether the samples are dependent or independent.

What is the difference between 1 tailed and 2 tailed t-test?

A one-tailed test is used to ascertain if there is any relationship between variables in a single direction, i.e. left or right. As against this, the two-tailed test is used to identify whether or not there is any relationship between variables in either direction.

What is the difference between one tailed and two-tailed test?

One-tailed tests allow for the possibility of an effect in one direction. Two-tailed tests test for the possibility of an effect in two directions—positive and negative.

What is the difference between a single sample t-test and a dependent means t-test?

Unlike the independent or dependent-sample t-tests, the one-sample t-test works with only one mean score. The one-sample t-test compares the mean of a single sample to a predetermined value to determine if the sample mean is significantly greater or less than that value.

When should a one-tailed test be used?

So when is a one-tailed test appropriate? If you consider the consequences of missing an effect in the untested direction and conclude that they are negligible and in no way irresponsible or unethical, then you can proceed with a one-tailed test. For example, imagine again that you have developed a new drug.

When should a dependent samples t-test be used?

The dependent sample t-test is used when the observations or cases in one sample are linked with the cases in the other sample. This is typically the case when repeated measures are taken, or when analyzing similar units or comparable specimen.