alignByLoadings: Align constructs by loadings on first principal component.

In markheckmann/OpenRepGrid: Tools to Analyze Repertory Grid Data

Align constructs by loadings on first principal component.

Description

In case a construct loads negatively on the first principal component, the function alignByLoadings() will reverse it so that all constructs have positive loadings on the first principal component (see detail section for more).

Usage

alignByLoadings(x, trim = 20, index = TRUE)

Arguments

x	repgrid object.
trim	The number of characters a construct is trimmed to (default is 10). If NA no trimming is done. Trimming simply saves space when displaying the output.
index	Whether to print the number of the construct (e.g. for correlation matrices). The default is TRUE.

Details

The direction of the constructs in a grid is arbitrary and a reflection of a scale does not affect the information contained in the grid. Nonetheless, the direction of a scale has an effect on inter-element correlations (Mackay, 1992) and on the spatial representation and clustering of the grid (Bell, 2010). Hence, it is desirable to follow a protocol to align constructs that will render unique results. A common approach is to align constructs by pole preference, but this information is not always accessible. Bell (2010) proposed another solution for the problem of construct alignment. As a unique protocol he suggests to align constructs in a way so they all have positive loadings on the first component of a grid PCA.

Value

An object of class alignByLoadings containing a list of calculations with the following entries:

• cor.before: Construct correlation matrix before reversal

• loadings.before: Loadings on PCs before reversal

• reversed: Constructs that have been reversed

• cor.after: Construct correlation matrix after reversal

• loadings.after: Loadings on PCs after reversal

Note

Bell (2010) proposed a solution for the problem of construct alignment. As construct reversal has an effect on element correlation and thus on any measure that based on element correlation (Mackay, 1992), it is desirable to have a standard method for construct alignment independently from its semantics (preferred pole etc.). Bell (2010) proposes to align constructs in a way so they all have positive loadings on the first component of a grid PCA.

References

Bell, R. C. (2010). A note on aligning constructs. Personal Construct Theory & Practice, 7, 42-48.

Mackay, N. (1992). Identification, Reflection, and Correlation: Problems in the bases of repertory grid measures. International Journal of Personal Construct Psychology, 5(1), 57-75.

See Also

alignByIdeal()

Examples

# reproduction of the example in the Bell (2010)
# constructs aligned by loadings on PC 1
bell2010
alignByLoadings(bell2010)

# save results
a <- alignByLoadings(bell2010)

# modify printing of resukts
print(a, digits = 5)

# access results for further processing
names(a)
a$cor.before
a$loadings.before
a$reversed
a$cor.after
a$loadings.after

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