1.4 “DIRTY DATA” PROBLEMS
Do all the data-entry people around the world who feed a continual stream of raw data into computer systems. A lot of database problems in particular are caused by this kind of dirty data. Dirty data is incomplete, outdated, or otherwise inaccurate data.
Some common causes of dirty data
Wrong field sizes
• Wrong and inconsistent data formats
• Logical inconsistency—for example, typing zip codes into phone number boxes, spelling the same name different ways
• User errors resulting from lack of training, misunderstanding procedures, and the like
• Most of the problems arise when database input workers are dealing with text or spreadsheet files—especially files from many different countries
A good reason for having a look at your records—credit, medical, school—is so that you can make any corrections to them before they cause you complications. Although databases are a time-saving resource for information seekers, they can also act as catalysts, speeding up and magnifying bad data.