CHARACTERISTICS OF RESEARCH TOOLS:
An ideal measuring instrument is one which results in measures that are relevant, accurate objective, sensitive and efficient. Measures which are physical or physiological have a higher chance of success in attaining these goals than measures that are psychological and behavioural. A number of techniques have been developed to evaluate the quality of the measuring tool to minimize error. You have already read about the characteristics of standardize evaluation tool. However when you construct a tool or select a tool you must ensure the following characteristics:
i) Validity
Refers to the degree to which the tool measures, what it is intended to measure. It refers to whether the instrument or scale is quantifying what it claims to e.g. weight 'scale measures body weight and it is valid; a tool which is valid for one measure, need not be valid for another e.g. in the case of weighing scale: it is not valid to measure temperature.