I got a question today about the difference between nominal, ordinal, ratio and interval data.

Nominal applies to data that consist of names, labels or categories.. Ex: Atlantic, Pacific, India, Arctic....... names of oceans

Ordinal applies to data that can be arranged in order.. example: in a class of 320 students, John ranked 25th, Joe ranked 35th, Amy ranked 10th, Julie ranked 4th

Interval applies to data that also can be arrange in order but the differences in order are important, they are not important in ordinal   ex: temperature.. you can order temperatures and observe meaningful difference

Ratio: data is arranged in order and there is a ratio between the values of the data... ex: length of fish in a river.. 18 inch fish is 3 times the length of a 6 inch fish.. 6 inch fish is 3 times the length of a 2 inch fish, etc