No matter what the cause, if your data set contains any unexpected values you want to know about it.
The reasons vary from the mundane (someone entered an impossible value for a variable) to the technical (different sample sizes accompanying different variances).Īny of those events could happen, whether the source of the data is a sales ledger, a beautifully designed medical experiment or a study of political preferences. Regardless of the sort of analysis you have in mind for a particular data set, you want to understand the distribution of the variables in that set. Analyzing One Factor by Another: The Contingency Table
