What is Messy Data?

Inconsistent formats, unnecessary white space, extra characters, typos, etc… Messy data is the bane of analysis! Each row contains exactly the same info:

2015-10-14 $1,000 ID
10/14/2015 1000 I.D.
10/14/15 1,000 US-ID
Oct 14, 2015 1000 dollars idaho
Wed, Oct 14th US$1000 Idaho,
42291 $1k Ihaho

Multivalued cells limit ability to manipulate and use the data:

“Using OpenRefine by Ruben Verborgh and Max De Wilde, September 2013”