Reliability & Validity

Actwhat is the difference between reliability and validity in what respects are they similar The real difference between reliability and validity is mostly a matter of definition. Reliability estimates the consistency of your measurement, or more simply the degree to which an instrument measures the same way each time it is used in under the same conditions with the same subjects. Validity, on the other hand, involves the degree to which you are measuring what you are supposed to, more simply, the accuracy of your measurement.It is my belief that validity is more important than reliability because if an instrument does not accurately measure what it is supposed to, there is no reason to use it even if it measures consistently (reliably). Reliability & Validity We often think of reliability and validity as separate ideas but, in fact, they’re related to each other. This is the two ways you can think about their relationship. The metaphors for the relationship between reliability are that of the target. Think of the center of the target as the concept that you are trying to measure.Imagine that for each person you are measuring, you are taking a shot at the target. If you measure the concept perfectly for a person, you are hitting the center of the target. If you don’t you are missing the center. The more you are off for that person, the further you are from the center. The figure above shows four possible situations. In the first one you are hitting the target consistently but you are missing the center of the target. That is, you are consistently and systematically measuring the wrong value for all respondents. This measure is reliable, but no valid that is, it’s consistent but wrong.The second shows hits that are randomly spread across the target. You seldom hit the center of the target but, on average you are getting the right answer for the group but not very well for individuals. In this case, you get a valid group estimate, but you are inconsistent. Here, you can clearly see that reliability is directly related to the variability of your measure. The third scenario shows a case where your hits are spread across the target and you are consistently missing the center. Your measure in this case is neither reliable nor valid. Finally, you consistently hit the center of the target. Your measure is both reliable nd valid. Employment Background Checks A background check or background investigation is the process of looking up and compiling criminal records, commercial records and financial records (in certain instances such as employment screening) of an individual. Background checks are often requested by employers on job candidates, especially on candidates seeking a position that requires high security or a position of trust, such as in a school, hospital, financial institution, airport, and government. These checks are traditionally administered by a government agency for a nominal fee, but can also be administered by private companies.Results of a background check typically include past employment verification, credit score, and criminal history. These checks are often used by employers as a means of objectively evaluating a job candidate’s qualifications, character, fitness, and to identify potential hiring risks for safety and security reasons. Background check is also used to thoroughly investigate potential government employees in order to be given a security clearance. However, these checks may sometimes be used for illegal purposes, such as unlawful discrimination (or employment discrimination), identity theft, and violation of privacy.