**R Scripts**

## A collection of R scripts and other resources that I have created and modified.

**ryychangescore.r**

This is a script for calculating and visualizing various reliable change indices (RCIs), "minimum detectable change" values for change scores, and RCI confidence intervals.

Indices Include:

- Jacobson-Truax Method

- Gulliksen-Lord-Novick Method (Adjusted for Regression to Mean)

- Edwards-Nunnally (Confidence Interval Method)

To visualize the data, this script also plots histograms of RCIs and change scores and RCI confidence intervals (See examples).

**A Primer on RCIs**: RCIs are statistics that suggest whether or not there is an appreciable change in an

*individual's*score between two measurements that cannot be explained by measurement error. There are many situations in which it is helpful to quantify who has changed over time (e.g., time-one to time-two differences, pre-post test/intervention scores). Because RCIs address the question, "Who has really changed and by how much?," they are particularly useful for classification (e.g., degree of change).

ryychangescore.r | |

File Size: | 2 kb |

File Type: | r |

**moderation.r**

A simple R Script for plotting continuous-by-continuous interactions using Base R Graphics, and following the classic suggestions of Cohen, Cohen, West, and Aiken (i.e., -1 SD, Mean, +1 SD):

moderation.r | |

File Size: | 0 kb |

File Type: | r |

**corstars.r**

A nice little R Script that calculates and displays the lower diagonal of a correlation matrix with significance stars:

Note: Requires 'Hmisc'

corstars.r | |

File Size: | 1 kb |

File Type: | r |

**rescon.r**

A set of scripts and helpful syntax for running simulations to facilitate investigating the residualization of predictors/criteria with respect to covariates (i.e., control variables -- hence, 'rescon' for

__res__idualized

__con__trols) in hierarchical OLS regression models under different conditions (e.g., varying predictor-covariate inter-correlations and sample sizes):

Note: Requires 'lattice' and 'car'

rescon.r | |

File Size: | 1 kb |

File Type: | r |

**Other Statistical Resources**

**"Other" statistical resources that I have cobbled together...**

**Plotting Conditional Indirect Effects from PROCESS**

This spreadsheet will plot continuous confidence intervals for conditional indirect effects that are derived from Andrew Hayes' "PROCESS" Macro for SPSS. This type of plot is described in Preacher, Rucker and Hayes (2007, p. 214). This spreadsheet was modified from one that was originally developed by DeCoster (2009) to work with the MODMED Macro, but is re-designed to work better with PROCESS outputs:

plotting_conditional_indirect_effects_from_process.xls | |

File Size: | 39 kb |

File Type: | xls |