Obama is a charismatic man and was a promising candidate, but the key to his successful campaign was possibly the application of microtargeting, achieved through the use of big data. ¿How did they it? Although the election is anonymous, results by voting center are public. That information can be enriched with data from the locality, not only sociodemographic facts, but also things like occupation, memberships, political and charitable contribution history, political volunteer history, permits and licenses, magazine subscriptions, etc.
If we see data cleaning as a process of detecting, diagnosing and editing data abnormalities, then we have to use every tool available in order to find those cases. The traditional and simple approach is process data and check out each variable, looking for subjects whit a significant distance in relation to the central points of the distribution. These values have to be confirmed, and, in the worst case, deleted.