alignByLoadings: Align constructs by loadings on first pricipal component.

In OpenRepGrid: Tools to analyse repertory grid data

Description

Align constructs by loadings on first pricipal component. 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 deatil section for more).

Usage

alignByLoadings(x, trim=20, output=0, digits=1)

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.
output	Numeric. The function returns either the repgrid object with aligned constructs (output=0 or 1), additionaly prints the calculation results to the console (output=1) or returns a list containing the calculation results, i.e. correlation matrices before and after reversal, loadings on first PC before and after reversal and a list (printout) of the constructs that have been reversed.
digits	Numeric. Number of digits to round to (default is 2).

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

Aligned repgrid object for output=0 or 1 or a list for output=2.

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 desireable 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.

Author(s)

Mark Heckmann

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 ihe bases of repertory grid measures. International Journal of Personal Construct Psychology, 5(1), 57-75.

See Also

alignByIdeal

Examples

## Not run: 

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

alignByLoadings(bell2010, output=2)  # show results


## End(Not run)

OpenRepGrid documentation built on May 2, 2019, 4:54 p.m.