Types of Data Problems

Duplicate Data $-$ when the data in all columns is identical for two or more rows

Inconsistent values $($in one column$)-$due to spelling, spaces, punctuation, abbreviation

Blank cells $-$ missing data that should be there

Numbers that aren't numbers

Multiple Values per cell

Outliers & Incorrect Values

Inconsistent Related values $-$ when the data in one or more column is inconsistent with the data

in another column for the same row $($between columns$)$