VOStat's missing data policy

Statistical data sets are often riddled with missing values. These often cause standard statistical methods in R to break down in unexpected ways. To avoid such possibilities VOStat filters out all rows of the data set that has at least one missing value. This filtering is built into the uploading process. VOStat reports the indices of the deleted rows as part of the data summary.

Let us look at an example. Suppose that your data set is as follows, where the red cells have missing values, and the green cells have actual values.

Important columns	Unimportant columns

Then VOStat will filter away all the rows (and produce an error message complaining that the data set has size 0), as each row in the data set has at least one missing value. This, however, is hardly desirable, as all the missing values occur only in the unimportant columns. A good strategy here would be to remove the unimportant columns (using some other software) prior to uploading the data into VOStat, as VOStat has no way of knowing which columns are important and which are not.