indexIntensity {OpenRepGrid}

Intensity index

Description

Calculate intensity index.

Usage

indexIntensity(x, rc = FALSE, trim = 30)

Arguments

x

A repgrid object.

rc

Whether to use Cohen's rc for the calculation of inter-element correlations. See elementCor() for further explanations of this measure.

trim

The number of characters a construct is trimmed to (default is 30). If NA no trimming occurs. Trimming simply saves space when displaying correlation of constructs or elements with long names.

Details

The Intensity index has been suggested by Bannister (1960) as a measure of the amount of construct linkage. Bannister suggested that the score reflects the degree of organization of the construct system under investigation (Bannister & Mair, 1968). The index resulted from his and his colleagues work on construction systems of patient suffering schizophrenic thought disorder. The concept of intensity has a theoretical connection to the notion of "tight" and "loose" construing as proposed by Kelly (1991). While tight constructs lead to unvarying prediction, loose constructs allow for varying predictions. Bannister hypothesized that schizophrenic thought disorder is liked to a process of extremely loose construing leading to a loss of predictive power of the subject's construct system. The Intensity score as a structural measure is thought to reflect this type of system disintegration (Bannister, 1960).

Implementation as in the Gridcor program and explained on the correspoding help pages: "... the sum of the squared values of the correlations of each construct with the rest of the constructs, averaged by the total number of constructs minus one. This process is repeated with each element, and the overall Intensity is calculated by averaging the intensity scores of constructs and elements." (Gridcor manual). Currently the total is calculated as the unweighted average of all single scores (for elements and construct).

Value

An object of class indexIntensity containing a list with the following elements:

c.int: Intensity scores by construct. e.int: Intensity scores by element. c.int.mean: Average intensity score for constructs. e.int.mean: Average intensity score for elements. total.int: Total intensity score.

Development

TODO: Results have not been tested against other programs' results.

References

Bannister, D. (1960). Conceptual structure in thought-disordered schizophrenics. The Journal of mental science, 106, 1230-49.

Examples

indexIntensity(bell2010)
indexIntensity(bell2010, trim = NA)

# using Cohen's rc for element correlations
indexIntensity(bell2010, rc = TRUE)

# save output
x <- indexIntensity(bell2010)
x

# printing options
print(x, digits = 4)

# accessing the objects' content
x$c.int
x$e.int
x$c.int.mean
x$e.int.mean
x$total.int