@Anandu wrote: So then what is the answer does the validation with difference in observation but with same value. Got succeeded or failed due to difference in number of observation. It was an exam question MCQ I vote failed.  Especially if the question was about validating a dataset.  It's possible if someone said "validating the data in the smaller dataset" they might claim it passed, but if I had to choose for a test, I'd definitely choose failed.   I love the ERROR option for proc compare when validating data.   12 proc compare base=a compare=b error; 13 run; ERROR: Data set WORK.B contains 1 observations not in WORK.A. ERROR: The data sets WORK.A and WORK.B do not contain the same data. One or both data sets contain variables or observations not in the other. However, all comparisons are equal for the data in common. NOTE: There were 5 observations read from the data set WORK.A. NOTE: There were 6 observations read from the data set WORK.B. ... View more