A non-parametric test for the null hypothesis that a random sample has been drawn from a specified distribution (either discrete or continuous). There are several similar tests, each involving a comparison of the sample distribution function with that hypothesized. For example, let the sample values, in increasing order, be x(1), x(2),…, x(n). Let the hypothesized probability of a value less than or equal to x(j) be pj. Let uj and vj be defined by
The test statistic is the largest of the absolute magnitudes of these 2n differences. A two-sample version of the test compares the two sample distribution functions. In the single-sample case, approximate critical values are at the 5% level and at the 1% level. The test was introduced by Kolmogorov in 1933, and further developed by Smirnov in 1939.
As described, the test refers to a fully prescribed distribution. However, by using special tables of critical values and estimating unknown parameters from the sample data, its use has been extended to testing for exponential, extreme-value, logistic, normal (the Lilliefors test), and Weibull distributions with unspecified parameters.
As an example, to test the hypothesis that the values 0.273, −1.184, 1.456, −0.655, −0.323, −0.733, −1.600, 0.819, 0.081, 0.971 have been drawn from a standard normal distribution the results given in the table are obtained.
 value  | j/n  | pj  | (j−1)/n  | uj  | vj  | 
|---|
−1.600 x=10 a=27 b=87 w=0.25>  | 0.1  | 0.055  | 0.0  | 0.045  | 0.055  | 
−1.184  | 0.2  | 0.118  | 0.1  | 0.082  | 0.018  | 
−0.733  | 0.3  | 0.232  | 0.2  | 0.068  | 0.032  | 
−0.655  | 0.4  | 0.256  | 0.3  | 0.144  | −0.044  | 
−0.323  | 0.5  | 0.373  | 0.4  | 0.127  | −0.027  | 
0.081  | 0.6  | 0.532  | 0.5  | 0.068  | 0.032  | 
0.273  | 0.7  | 0.608  | 0.6  | 0.092  | 0.008  | 
0.819  | 0.8  | 0.793  | 0.7  | 0.007  | 0.093  | 
0.971  | 0.9  | 0.834  | 0.8  | 0.066  | 0.034  | 
1.456  | 1.0  | 0.927  | 0.9  | 0.073  | 0.027  | 
  The value of the test statistic is 0.144, which is much less than 1.36/=0.41: so the null hypothesis is acceptable.