In markheckmann/OpenRepGrid: Tools to Analyze Repertory Grid Data

knitr::opts_chunk$set(collapse = TRUE, comment = "#")
library(OpenRepGrid)
options(width=120)
settings(show.scale=FALSE, show.meta=FALSE)

Description

As a measure for element similarity correlations between elements are frequently used. Note that product moment correlations as a measure of similarity are flawed as they are not invariant to construct reflection [@mackay_identification_1992; @bell_note_2010]. A correlation index invariant to construct reflection is Cohen's rc measure [-@cohen_rc:_1969], which can be calculated using the argument rc=TRUE which is the default option.

R-Code

As a default the construct reflection invariant correlation Cohen's rc is calculated.

Note how the values change when the simple product-moment correlation is used instaed of Cohen's rc. Make sure you know what you are doing when setting rc=FALSE.

elementCor(mackay1992, rc=F)

Although nor recommended different measures, not invariant to construct relfection, can be prompoted, when setting rc=FALSE.

• Pearson or Product-moment correlation (PMC)
• Kendall's tau rank correlation
• Spearman's rank correlation

To request these types of correlations use the method argument plus rc=FALSE.

elementCor(mackay1992, rc=FALSE, meth="kendall")    # Kendalls tau correlation
elementCor(mackay1992, rc=FALSE, meth="spearman")   # Spearman rank correlation

Several arguments to format the output are available.

elementCor(mackay1992, index=F, trim=6)

If the correlations are calculated for further processing, the correlations can be saved.

r <- elementCor(mackay1992)

The object is matrix, so you can eassily acces the results. E.g. all correlations with the element Self.

r[1, ]

Literature

markheckmann/OpenRepGrid documentation built on April 14, 2024, 8:15 a.m.