Probable Error is an expected error in Karl Pearson‘s coefficient of correlation, which facilitates the upper limit and lower limit of possible correlation. With the help of probable error it is possible to determine the reliability of the value of the coefficient in so far as it depends on the conditions of random sampling. Formula to calculate probable error :
Where –
r → Coefficient of correlation.
N → No. of items
Standard Error : Now a days Standard Error is preferred to probable error. Degree of standard error is standard deviation of sampling distribution in any statistics of random sampling.
Other things remaining the same, it is essential that standard error should be small as far as possible. Smaller the standard error, more uniformity will be there in sampling distribution.
If coefficient of correlation is more than 6 times of probable error (r > 6 P.E), it is significant.
(ii) If r is less than P.E. (r < P.E) it is not significant.
(iii) If r is less than 0.3 P.E (r < 0.3 P.E) it is insignificant.
