From Pitstop4Performers channel


Wednesday, May 27, 2009

Reliability vs validity

"Reliability and validity are two important characteristics of any measurement procedure. Reliability refers to the confidence we can place on the measuring instrument to give us the same numeric value when the measurement is repeated on the same object. Validity on the other hand means that our measuring instrument actually measures the property it is supposed to measure. Reliability of an instrument does not warranty its validity."
"For example, there may be an instrument which can measure the number of things a child can recall from his last one day's activities. If this instrument returns the same value when implemented on the same child, it is a reliable instrument. But if someone claims that it is a valid instrument for measuring the IQ level of the child, he may be wrong. This instrument may just be measuring the memory level and not the IQ level of the child."
(Ajai S. Gaur and Sanjaya S. Gaur in 'Statistical Methods for Practice and Research: A guide to data analysis using SPSS,' p. 31 Response)

1 comment:

  1. thanks for clear definition of validity & reliability.