Abscissa and ordinate Abscissa and ordinate In mathematics, the abscissa (; plural "abscissae" or "abscissæ" or "abscissas") and the ordinate are respectively the first and second coordinate of a point in a coordinate system. The abscissa of a point is the signed measure of its projection on the primary axis, whose absolute value is the distance between the projection and the origin of the axis, and whose sign is given by the location on the projection relative to the origin (before: negative; after: positive). The ordinate of a point is the signed measure of its projection on the secondary axis, whose absolute value
Paired data medicine. In this case the data is "paired" as it is likely the blood pressure "after" giving the medicine will be related to the blood pressure of that patient "before" the medicine was given. The statistical tests used to compare sets of data have been designed for data that is either paired or unpaired and it is important to use the correct test to prevent erroneous results. Examples of tests for unpaired data: Examples of tests suitable for paired data: Paired data Scientific experiments often consist of comparing two or more sets of data. This data is described as unpaired