Reliability

When we call a person reliable, we mean that one can trust her to do what she promised to do. In other words, a reliable person shows behavior one expects. Technical devices typically are classified as reliable or unreliable. As cars grow older, technical malfunctioning becomes more likely, and they gradually become unreliable, meaning they no longer can be expected to take you from A to B without problems. Technical definitions of reliability also have entered the nonscientific arena. The Merriam-Webster dictionary defines reliability as “the extent to which an experiment, test, or measuring procedure yields the same results on repeated trials” (retrieved from http://www.merriam-webster.com/dictionary/reliability). This definition emphasizes repeatability of results when one collects new data under the same conditions as data were collected previously, and it comes close to what psychometric reliability is. The Oxford..