Data in Xynk is divided into **measures**
See Data Files section for more on the expected format and structure of Xynk datasets.. Measures include the discrete independent variables (or factors or measures) imposed or selected by the experimenter, and the continuous dependent variables or measures that are recorded by the experimenter at each level of the independent measures for each subject.

Xynk refers to the independent measures as **Categorical measures** (marked in the Measures list with a "C" icon), and the dependent measures as **Numeric measures** (marked by an "#" icon).

Measures are the basic units for plotting and analysis. A graph in Xynk is the plot of a Categorical Measure (along the X-axis) against a Numeric Measure (along the Y-axis). Xynk only plots categorical graphs; the current version does NOT plot Numeric measure vs. Numeric measure, and so Xynk is not suitable for eg. correlation analysis of two continuous variables. An example would be to plot the data from an experiment measuring the effect of a drug, administered at different doses, on the amount of water consumed by the subjects. In this case, the independent Categorical Measure is the experimental groups receiving different "Drug Dose", and the Numeric Measure is the recorded "Intake":

A data set can have more than one Categorical Measure, and more than one Numeric measure. For example, the example experiment might also have grouped the subjects into "mutant" and "wildtype", and thus had a Categorical Measure called "genotype". The investigator may also have collected numeric measures (observations) other than "Food Intake", such as "Body Weight". So for this data set, Xynk could plot "genotype" vs. "Food Intake", or "Drug Dose" vs. "Body Weight", or "genotype" vs. "Body Weight": You can change which measures are plotted by clicking on the measures in the Measures source list, or by selecting the Y-Axis measure or X-Axis measure from the Measures Bar popups above the graph.