Characteristics of Good Average
a.It should be Rigidly Defined An average should be rigidly defined so that there is no confusion in regard to its meaning and connotation. If it is not well defined it may be influenced by the prejudice and personal bias of the investigator making its value unstable and render it unrepresentative of the distribution.
b.Its Definition Should be in the Form of a Mathematical Formula With mathematical formulation different persons may not interpret it differently and anybody computing the average from a set of data will arrive at the same figure i, e, it should not depend upon the whim or caprice of the person computing it.
c.It Should be Easy to Calculate and Simple to Follow An average should be simple in comprehension so that it can he calculated with reasonable case and rapidity else its use will be very limited.
d.It Should be Based on all Observation in the Series An average will be truly representative of the whole mass of data if it is computed from all the observations.
e It Should not be Affected Much by a Few Extreme Values A few very small or very large observations should not unduly affect the value of a good average.
f. It Should be Capable of Further Algebraic Treatment An average should lend itself readily to further algebraic treatment. For example if average of two or more sets of data are known it should be possible to obtain the average of combined group.
g.It Should be Capable of Being Used in Further Statistical Computation or Processing's An average should posses this quality e, g, arithmetic mean is suitable for calculating standard deviation else it will not be of great use in further statistical analysis and its utility will be limited.
It Should possess Sampling Stability An average should be least affected by sampling. By this we mean that if we take independent random samples of the same size from a given population and compute the average each of these samples in an ideal average, the values so obtained from different samples should not vary much from one another