**R**
r (Pearson Correlation Coefficient)
Radial Basis Functions
Random Effects (in Mixed Model ANOVA)
Range Ellipse
Range Plots - Boxes
Range Plots - Columns
Range Plots - Whiskers
Ratio Scale
Raw Data, 3D Scatterplot
Raw Data Plots, 3D - Contour/Discrete
Raw Data Plots, 3D - Spikes
Raw Data Plots, 3D - Surface Plot
Rayleigh Distribution
Regression
Regression, Multiple
Regular Histogram
Regular Line Plots
Regular Scatterplot
Regularization in Neural Networks
Reject Threshold
Relative Function Change Criterion
Reliability
Reliability and Item Analysis
Residual
Resolution
Response Surface
Right Censoring
RMS (Root Mean Squared) Error
Root Mean Square Standardized Effect (RMSSE)
Rosenbrock Pattern Search
Rotating Coordinates, Method of
Runs Tests (in Quality Control)