Characteristics that a scientific measuring tool should have

RELIBILITY - is the consistency of your measurement, or the degree to which an

instrument measures the same way each time it is used under the same condition with the

same subjects. In short, it is the repeatability of your measurement. A measure is considered

reliable if a person's score on the same test given twice is similar. It is important to

remember that reliability is not measured, it is estimated. A good instrument will produce

consistent scores. An instrument’s reliability is estimated using a correlation coefficient of

one type or another.

VALIDITY

VALIDITY - Validity is the extent to which a test measures what it claims to measure. It is

vital for a test to be valid in order for the results to be accurately applied and interpreted.

Validity isn’t determined by a single statistic, but by a body of research that demonstrates

the relationship between the test and the behavior it is intended to measure. There are three

types of validity: It is the strength of our conclusions, inferences or propositions. More

formally, Cook and Campbell (1979) define it as the "best available approximation to the

truth or falsity of a given inference, proposition or conclusion."

PRACTICIBILITY

PRACTICIBILITY - It should be feasible & usable. Quality of being usable in context to the

objective to be achieved.

USABILITY

USABILITY(practicality) ease in administration, scoring, interpretation and application, low

cost, proper mechanical make – up

MEASUREABILITY

MEASUREABILITY - It should measure the objective to be achieved.

Explanation: