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