I am unable to understand the difference if a data is text value, how to differentiate it as nominal or ordinal?
Welcome to DQ Community!
Nominal data is something that can’t be ordered. There is no low and high, small or big just naming different values differently.
Example: Our names - Divya, Josh, Bruno, Rucha etc. There is no apparent reason for us to order this. Even if we order it alphabetically - Bruno, Divya, Josh, Rucha we can’t say “Divya” is better than “Rucha” or vice-versa because it is second in the list.
Ordinal Data is something that can be ordered. Each value indicates some level of comparison.
Example: A food item you had. You can categorize it any of the below:
disgusting, un-appetizing, bland, okay, nice, loved-it!
Each category is able to measure your liking or disliking. For analysis you can also convert them to numbers - like
disgusting can be
scored as 0, then
become 5. or you can label it the other way round. So lowest number becomes best rated and highest number shows how awful it was.
In the example attached, the style of roof is just an attribute - it just tells us what style/ shape of the roof is. It doesn’t tell us which is better or which is worst.
On the other hand, the land-slope tells us the level of slope even if it’s just 3 different categories, we can easily understand, the construction would be different for a house on a very steep slope than on a gentle slope.
Hope that helps.
Thank you Rucha, it is really one of the best explanation I have ever read about Nominal and Ordinal data. Thanks to you, I understood more
glad it helped you.
Nominal data is basically anything that is just a name. Things like Postal Code is also considered Nominal data as the numbers is a name for an address
Ordinal Data is data that have values that can be arranged from big to small. Note that numbers can also be Ordinal Data like Shoe Size because US 8 is bigger than US 7