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What is Reliability?

Split-half method

❶Quantifying Quality and Qualifying Quantity.

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Reliability in research
Assessing Reliability
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Human judgment can vary wildly between observers , and the same individual may rate things differently depending upon time of day and current mood. This means that such experiments are more difficult to repeat and are inherently less reliable. Reliability is a necessary ingredient for determining the overall validity of a scientific experiment and enhancing the strength of the results. Debate between social and pure scientists, concerning reliability, is robust and ongoing.

Validity encompasses the entire experimental concept and establishes whether the results obtained meet all of the requirements of the scientific research method. For example, there must have been randomization of the sample groups and appropriate care and diligence shown in the allocation of controls.

Internal validity dictates how an experimental design is structured and encompasses all of the steps of the scientific research method. Even if your results are great, sloppy and inconsistent design will compromise your integrity in the eyes of the scientific community. Internal validity and reliability are at the core of any experimental design.

External validity is the process of examining the results and questioning whether there are any other possible causal relationships. Control groups and randomization will lessen external validity problems but no method can be completely successful. This is why the statistical proofs of a hypothesis called significant , not absolute truth. Any scientific research design only puts forward a possible cause for the studied effect.

There is always the chance that another unknown factor contributed to the results and findings. This extraneous causal relationship may become more apparent, as techniques are refined and honed. If you have constructed your experiment to contain validity and reliability then the scientific community is more likely to accept your findings.

Eliminating other potential causal relationships, by using controls and duplicate samples, is the best way to ensure that your results stand up to rigorous questioning.

Check out our quiz-page with tests about:. Martyn Shuttleworth Oct 20, Retrieved Sep 11, from Explorable. The text in this article is licensed under the Creative Commons-License Attribution 4.

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Don't have time for it all now? No problem, save it as a course and come back to it later. Martyn Shuttleworth K reads. Share this page on your website: There, it measures the extent to which all parts of the test contribute equally to what is being measured.

This is done by comparing the results of one half of a test with the results from the other half. A test can be split in half in several ways, e. If the two halves of the test provide similar results this would suggest that the test has internal reliability. The reliability of a test could be improved through using this method. For example any items on separate halves of a test which have a low correlation e. The split-half method is a quick and easy way to establish reliability.

However it can only be effective with large questionnaires in which all questions measure the same construct. This means it would not be appropriate for tests which measure different constructs.

For example, the Minnesota Multiphasic Personality Inventory has sub scales measuring differently behaviors such depression, schizophrenia, social introversion. Therefore the split-half method was not be an appropriate method to assess reliability for this personality test.

The test-retest method assesses the external consistency of a test. Examples of appropriate tests include questionnaires and psychometric tests. It measures the stability of a test over time.

A typical assessment would involve giving participants the same test on two separate occasions. If the same or similar results are obtained then external reliability is established. The disadvantages of the test-retest method are that it takes a long time for results to be obtained. The timing of the test is important; if the duration is to brief then participants may recall information from the first test which could bias the results. Alternatively, if the duration is too long it is feasible that the participants could have changed in some important way which could also bias the results.

This refers to the degree to which different raters give consistent estimates of the same behavior. Inter-rater reliability can be used for interviews. Note, it can also be called inter-observer reliability when referring to observational research. Here researcher when observe the same behavior independently to avoided bias and compare their data.

If the data is similar then it is reliable. In this scenario it would be unlikely they would record aggressive behavior the same and the data would be unreliable. However, if they were to operationalize the behavior category of aggression this would be more objective and make it easier to identify when a specific behavior occurs.

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Reliability in research Reliability, like validity, is a way of assessing the quality of the measurement procedure used to collect data in a dissertation. In order for the results from a study to be considered valid, the measurement procedure must first be reliable.

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Internal validity dictates how an experimental design is structured and encompasses all of the steps of the scientific research method. Even if your results are great, sloppy and inconsistent design will compromise your integrity in the eyes of the scientific community. Internal validity and reliability are at the core of any experimental design.

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Test-retest reliability is a measure of reliability obtained by administering the same test twice over a period of time to a group of individuals. The scores from Time 1 and Time 2 can then be correlated in order to evaluate the test for stability over time. If findings from research are replicated consistently they are reliable. A correlation coefficient can be used to assess the degree of reliability. If a test is reliable it should show a high positive godliterature.tk: Saul Mcleod.

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Reliability has to do with the quality of measurement. In its everyday sense, reliability is the "consistency" or "repeatability" of your measures. Before we can define reliability precisely we have to lay the groundwork. First, you have to learn about the foundation of reliability, the true score theory of measurement. The use of reliability and validity are common in quantitative research and now it is reconsidered in the qualitative research paradigm. Since reliability and validity are rooted in positivist perspective then they should be redefined for their use in a naturalistic approach. Like reliability and.