REGIONS_OF_SIGNIFICANCE {SIMPLE.REGRESSION}

Plots of Johnson-Neyman regions of significance for interactions

Description

Plots of Johnson-Neyman regions of significance for interactions in moderated multiple regression, for both SIMPLE.REGRESSION models (objects) and for lme models from the nlme package.

Usage

REGIONS_OF_SIGNIFICANCE(model,
                        IV_range=NULL, MOD_range=NULL,
                        PLOT_title=NULL, Xaxis_label=NULL,
                        Yaxis_label=NULL, LEGEND_label=NULL,
                        namesIVMOD_raw=NULL, namesIVMOD_model=NULL)

Arguments

model

The name of a SIMPLE.REGRESSION model, or of an lme model from the nlme package.

IV_range

(optional) The range of the IV to be used in the plot.

MOD_range

(optional) The range of the MOD values to be used in the

PLOT_title

(optional) The plot title.

Xaxis_label

(optional) A label for the X axis to be used in the requested plot.

Yaxis_label

(optional) A label for the Y axis to be used in the requested plot.

LEGEND_label

(optional) The legend label for a moderated regression.

namesIVMOD_raw

optional, and for lme/nlme models only. If model is an lme object & IV is a two-level factor, then namesIVMOD_model must be specified (because lme alters the variable names).

namesIVMOD_model

optional, and for lme/nlme models only. The namesIVMOD_model argument can be used to id the key terms () from an lme model that involved more than IV, MOD, & Xn terms. The argument is used only to create the key B and S objects for the J-N analyses. Other terms in the model are ignored.

Value

An object of class "SIMPLE.REGRESSION". The object is a list containing the following possible components:

JN.data

The Johnson-Neyman results for a moderated regression.

ros

The Johnson-Neyman regions of significance for a moderated regression.

Author(s)

Brian P. O'Connor

References

Bauer, D. J., & Curran, P. J. (2005). Probing interactions in fixed and multilevel regression: Inferential and graphical techniques. Multivariate Behavioral Research, 40(3), 373-400.

Huitema, B. (2011). The analysis of covariance and alternatives: Statistical methods for experiments, quasi-experiments, and single-case studies. Hoboken, NJ: Wiley.

Johnson, P. O., & Neyman, J. (1936). Tests of certain linear hypotheses and their application to some educational problems. Statistical Research Memoirs, 1, 57-93.

Johnson, P. O., & Fey, L. C. (1950). The Johnson-Neyman technique, its theory, and application. Psychometrika, 15, 349-367.

Pedhazur, E. J. (1997). Multiple regression in behavioral research: Explanation and prediction. (3rd ed.). Fort Worth, Texas: Wadsworth Thomson Learning

Rast, P., Rush, J., Piccinin, A. M., & Hofer, S. M. (2014). The identification of regions of significance in the effect of multimorbidity on depressive symptoms using longitudinal data: An application of the Johnson-Neyman technique. Gerontology, 60, 274-281.

Examples

head(data_Cohen_Aiken_West_2003_7)

CAW_7 <- 
SIMPLE.REGRESSION(data=data_Cohen_Aiken_West_2003_7, DV='yendu',
                  IV='xage', IV_type = 'numeric', IV_range='tumble',
                  MOD='zexer', MOD_type = 'numeric', MOD_levels='quantiles', 
                  MOD_range=NULL,
                  quantiles_IV=c(.1, .9), quantiles_MOD=c(.25, .5, .75),
                  CENTER = TRUE, COVARS=NULL, 
                  PLOT_type = 'interaction', PLOT_title=NULL, 
                  Xaxis_label=NULL, Yaxis_label=NULL, LEGEND_label=NULL,
                  JN_type = 'Huitema', verbose=TRUE ) 

REGIONS_OF_SIGNIFICANCE(model=CAW_7,  
        IV_range=NULL, MOD_range='minmax', 
        PLOT_title=NULL, Xaxis_label=NULL, Yaxis_label=NULL, LEGEND_label=NULL,
        namesIVMOD_raw=NULL, namesIVMOD_model=NULL) 
	


head(data_Bauer_Curran_2005)

HSBmod <- nlme::lme(MathAch ~ Sector + CSES + CSES:Sector , 
			        data = data_Bauer_Curran_2005, 
			        random = ~1 + CSES|School, method = "ML") 
summary(HSBmod)

REGIONS_OF_SIGNIFICANCE(model=HSBmod,  
        IV_range=NULL, MOD_range=NULL, 
        PLOT_title=NULL, Xaxis_label=NULL, Yaxis_label=NULL, LEGEND_label=NULL,
        namesIVMOD_raw=NULL, namesIVMOD_model=NULL) 


# moderated regression	-- with numeric values for IV_range & MOD_levels='AikenWest'       
mharsh_agg <- SIMPLE.REGRESSION(data=data_OConnor_Dvorak_2001, DV='Aggressive_Behavior',
       IV='Maternal_Harshness', IV_type = 'numeric', IV_range=c(1,7.7), 
       MOD='Resiliency', MOD_type = 'numeric', MOD_levels='AikenWest', MOD_range=NULL,
       quantiles_IV=c(.1, .9), quantiles_MOD=c(.25, .5, .75),
       CENTER = FALSE, COVARS=NULL, 
       PLOT_type = 'interaction', 
       PLOT_title=NULL, 
       DV_range = c(1,6), 
       Xaxis_label='Maternal Harshness', 
       Yaxis_label='Adolescent Aggressive Behavior', 
       LEGEND_label='Resiliency',
       JN_type = 'Huitema', verbose=TRUE ) 

REGIONS_OF_SIGNIFICANCE(model=mharsh_agg,  
        IV_range=NULL, 
        MOD_range='minmax', 
        PLOT_title='Slopes of Maternal Harshness on Aggression by Resiliency', 
        Xaxis_label='Resiliency', 
        Yaxis_label='Slopes of Maternal Harshness on Aggressive Behavior ', 
        LEGEND_label=NULL,
        namesIVMOD_raw=NULL, 
        namesIVMOD_model=NULL)