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).