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Reliability vs. Validity – Difference You Need to Know


Students who are making a research paper need to focus on two essential aspects of their research. These two elements are reliability and validity. It is only when you pay attention to these two parts of your investigation, it will be successful. Many scholars, over the years, have shed light on the difference between validity and reliability. The quality assessment of any research for the purpose of writing a dissertation is based on these two parts. The measurement process should be reliable for your study to be deemed valid. Reliability means the extent to which your research approach or method generates cohesive results. Validity represents the extent to which a measuring instrument measures what it needs to measure. Thus, you can see that both these qualities differ considerably from one another. Let us explore the differences between them in more detail.

Become a better researcher

A skilled researcher has a clear understanding of the reliability and validity of their research. When you understand the difference, you will be able to create a quality dissertation.

1. Meaning of validity and its types

Validity means to remain accurate. It is considered a crucial yardstick that shows the degree to which your research instrument gauges. The three types of validity are:

  • Content validity – It means the point at which the scale gives sufficient coverage of the topic that is tested. It demonstrates if a measurement scale justifies the content domain or not.
  • Criterion validity –It determines the measuring instrument’s performance. Your criterion needs to be trustworthy, unbiased, and relevant.
  • Construct validity – It indicates the extent to which a test is measured and includes convergent validity, nomological validity, and discriminant validity.

2. What is reliability

The consistent result of a measurement that is conducted repeatedly is called reliability. There are multiple ways to determine if a research element is reliable. There are two aspects of this quality. These are:

  • Stability –The extent of stability can be found out by comparing the outcomes of repeated measurements. You can deem an element to be reliable after a stability assessment.
  • Equivalence – You can gauge the equivalence in reliability when you compare and contrast the observation of similar phenomena by different researchers.

3. Internal and external reliability

Internal reliability entails consistency of the measurement in itself. A suitable example, in this case, is that of personality tests. Such a test should generate results that are similar every time that it is conducted. External reliability is the degree to which a measure differs from one use to another.

4. Some more key differences between reliability and validity

Remember that a valid instrument is also reliable, but vice versa is not true. A reliable instrument is not always a valid one. Validity is more important when you are assessing a multi-item scale. You can easily determine the reliability of a specific measuring instrument, but assessing validity is a difficult task. Validity focuses entirely on correctness, while reliability focuses on precision, which measures the degree to which a measurement scale gives similar outcomes.

Now that you have more clarity over the differences between both these qualities, you will find yourself in a better place to do a quality dissertation.

Summary: Students in various universities involved in the task of creating research papers need to know the difference between qualities of effective research like validity and reliability. The article outlines the major differences between the two.


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