Repost from 1999: Much Ado About Nothing – An Orderly Representation of Null Values

July 6, 2011 by · Leave a Comment
Filed under: Data Profiling, Data Quality, Recommendations 

This is a repost of an article I wrote back in 1999, but I thought it might be interesting to recycle it, since it still seems relevant. I did edit it a little – I wrote it after the birth of my second child, who is now 11, so it did not make sense to refer to him as a baby ;-). Here it is:

A null value is a missing value. Yet a value that is “not there” may provide more information than one might think, because there may be different reasons that the value might be missing. A null value might actually represent an unavailable value, that the attribute is not applicable for this entity, that there is no value in the attribute’s domain that correctly classifies this entity, etc. Or the value may actually be missing!

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To Be, or Not To Be: Default Null Values

March 21, 2011 by · 1 Comment
Filed under: Data Profiling, Data Quality 

A long time ago I wrote an article about null values (you can still find it online at this location), and how there are often values inserted into a data element that are essentially absent values. You know what I am talking about, values like “Not available” or “N/A” that pepper the data set.
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