A pair of mantras that NICAR's Richard Mullins teaches his students at the Missouri School of Journalism is: "All databases are bad," and "All data is dirty." If you've worked with many databases, you soon realize the truth in these statements. Underpaid and overworked government data-entry clerks will forever confuse similar postal codes, such as Missouri (MO) and Montana (MT) or Connecticut (CT) and Colorado (CO). And even the most clever database designers cannot account for incomplete data.
Drew Sullivan can be reached at (800) 845-8450, ext. 7639, or send e-mail to drew@ap.org