Validity and Reliability

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Validity and Reliability

The principles of validity and reliability are fundamental cornerstones of the scientific method.
Together, they are at the core of what is accepted as scientific proof, by scientist and philosopher alike.

By following a few basic principles, any experimental design will stand up to rigorous questioning and skepticism.
What is Reliability?
The idea behind reliability is that any significant results must be more than a one-off finding and be inherently repeatable.

Other researchers must be able to perform exactly the same experiment, under the same conditions and generate the same results. This will reinforce the findings and ensure that the wider scientific community will accept the hypothesis.

Without this replication of statistically significant results, the experiment andresearch have not fulfilled all of the requirements of testability.

This prerequisite is essential to a hypothesis establishing itself as an accepted scientific truth.
For example, if you are performing a time critical experiment, you will be using some type of stopwatch. Generally, it is reasonable to assume that the instruments are reliable and will keep true and accurate time. However, diligent scientists take measurements many times, to minimize the chances of malfunction and maintain validity and reliability.

At the other extreme, any experiment that uses human judgment is always going to come under question.
For example, if observers rate certain aspects, like in Bandura’s Bobo Doll Experiment, then the reliability of the test is compromised. 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…...

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