Reliability and Validity

Reflection 4(ii)

Reliability and validity is a very interesting concept to me as I am teaching Language Test to my Diploma in TESL students. From my understanding and of course, from the lesson in class, this is what I understand about reliability and validity.

Reliability is more on the consistency of the result. Say, if I were to give out the questionnaire today, would the result be the same if I were to give the questionnaire tomorrow.

Validity on the other hand, is on whether I am testing the right thing; or the extend to which the test measures what it intends to measure. Say, if I were to measure someone's reading ability, the test given must be specific on reading. If a test on writing were given for this particular purpose, the this is not valid.

That is why, for my research, I would prefer to use an existing instrument. This is because, existing instruments would usually have a higher level of reliability and validity, thus making the result more accurate and significant.