The point is that you should get similar results from both halves of the test. You can do so by simply dividing the test into the first and second halves or using an odd and even method. Often, you can compare the results of one half of the test against the other half. It measures the extent to which all the test parts contribute equally to what is being measured. This method assesses the internal consistency of a test. The first is associated with internal reliability and it is known as the split-half method. There are several methods that are used to assess the reliability of a test. Therefore, these two aspects allow you to understand the reliability of the test itself, both from its components to how it compares when testing different items. Essentially, it is the extent to which a measure is consistent within itself.Įxternal reliability is the extent to which a measure will vary from one use to the next.

Internal reliability is used to assess the consistency of results across different items within the test itself. Both are necessary to determine the true reliability of a research test.įirst, let's start with internal reliability and what it means. Within psychology, there are two forms of reliability: internal and external. That means it can be considered an accurate test of the hypothesis. However, a strong positive correlation between the results is a good indication that the test or research is reliable. Since situations change and individuals are not always going to be the same in every instance that research is replicated, some difference in results is to be expected. When you redo a study, are the results the same or consistent from one instance to another? There is a correlation coefficient can be used to assess the degree of reliability such that a test should have a high positive correlation to be considered reliable. If the findings of a research study can be replicated consistently, then they can be considered reliable. The same is true of research findings in psychology. It would not be a reliable measuring device.

If a scale gave a different result every time you weighed the same item, it would essentially be useless. Think of it this way: if you are weighing something on different scales, you would expect to get essentially the same results every time. The term reliability, when it refers to psychological research, is focused on the consistency of a research study or measuring test.

Reliability and validity psychology