SHORTER ALTERNATIVES TO THE CALIFORNIA PSYCHOLOGICAL INVENTORY (CPI)

Monica Albu

(articol apărut în Volumul de lucrări ale Conferinţei Internaţionale de Psihologie Aplicată, 17-19 mai 2001, Sinaia, Editura Augusta, Timişoara, 2002).

 

            Abstract. A California Psychological Inventory deficiency is the great number of its items (over 400, in each of its versions). In this paper are presented two reduced versions of CPI, in which each scale contains less items than the original however has a better internal consistency.

 

            The California Psychological Inventory (CPI) was built by H. G. Gough, in order to provide psychologists with an instrument that could be used for diagnosis and prediction of interhuman behaviour. The items in the inventory refere to social behaviour, attitudes and personal relations. The intentions stipulated for the scales of the inventory are: (a) to predict what people will say and do in specified contexts, and (b) to identify individuals who will be evaluated and described in diferentiating and interpersonally significant ways.

            There are more versions of CPI, that differ from each other from the point of view of items number (480, 462 and, recently, 434). The research presented below used the version with 462 items.

            This version has 20 standard scales, designed in such way as to highlight folk concepts – that is, concepts that arise from and are linked to the processes of interpersonal life, and that are to be found everywhere that humans congregate into groups and establish societal functions. The standard scales were grouped in the following categories (Gough, 1987):

· Measures of Poise, Self-Assurance, and Interpersonal Proclivities: Do (Dominance), Cs (Capacity for Status), Sy (Sociability), Sp (Social Presence), Sa (Self-acceptance), In (Independence), Em (Empathy).

· Measures of Normative Orientation and Values: Re (Responsibility), So (Socialization), Sc (Self-control), Gi (Good Impression), Cm (Communality), Wb (Well-being), To (Tolerance).

· Measures of Cognitive and Intellectual Functioning: Ac (Achievement via Conformance), Ai (Achievement via Independence), Ie (Intellectual Efficiency).

· Measures of Role and Personal Style: Py (Psychological-mindedness), Fx (Flexibility), FM (Feminity/Masculinity).

            On analysing the version with 462 items, translated and adapted for the Romanian language by H. Pitariu, based on answers given by 1,000 people, two important flaws have been noticed:

            · completing the questionnaire takes about one hour;

            · the internal consistency of the scales is low.

            In order to eliminate these problems we tried to build a questionnaire based on items from CPI, to which the following conditions were imposed:

            · the total number of items should be smaller than 462;

            · the questionnaire should consist of 20 scales, corresponding to the 20 standard CPI scales;

            · the scales should have better internal consistency than the CPI scales.

            The building of the new questionnaire was accomplished in 4 steps:

1. Six psychologists identified those items in CPI which were formulated incorrectly (they could be interpreted in more ways, they addressed only a part of the subjects or they contained negatives). 130 items were found. It was decided not to include those items in the questionnaire.

2. For each standard CPI scale, groups of 3 psychologists indicated items which could be included in it, considering Gough’s definition for the concept measured by the scale.

3. For each standard CPI scale, a group of items was formed, consisting of:

· items from the original scale which were not eliminated during step 1;

· items formulated by psychologists in step 2 and which originally didn’t belong to that particular scale.

Two psychologists analysed the items and highlighted those items which, in their opinion, were the most representative for what scale measured.

4. On the computer and using an original algorithm, more alternatives were built for each standard scale. For each of them, we started from a representative item (marked during step 1), and we took out items from the group formed for that particular scale, pursuing the best internal consistency for that scale. To achieve this, for each step of the algorithm, we chose the item that, by being added to the scale in the form it had at that moment, produced the highest increase of the Kuder-Richardson 20 (KR20) internal consistency coefficient. The algorithm stopped when the value of the coefficient started to go down.

During this step, for each standard scale we used two methods:

a. We didn’t limit the number of items in the scales we formed. Of the scales that were built, the one with the best internal consistency was chosen. This way, we obtained the CL questionnaire, with 249 items.

b. We tried to obtain, in each scale, about half the number of items in the standard CPI scale and, besides, we wanted the KR20 coefficient to be bigger than the KR20 in the standard scale. This way, we obtained the CS questionnaire, with 213 items.

In order to check if the two questionnaires measured the same concepts as the CPI standard scales, we calculated, for each standard scale, the linear correlation coefficient between the scores of standard scales and the scores of corresponding scales in CL and CS. To accomplish this, we used answers provided to CPI by a number of 1141 persons (668 males and 473 women). In table 1 it can be noticed that all the linear correlation coefficients are significant on the threshold p=0.001. We can conclude from here that the new scales measure the same concepts as the standard CPI scales. So, to interpret the scores of the subjects we can use the descriptions given by Gough to “high” scores and, respectively, “low” scores (Pitariu, Albu, 1993).

Using the same group of subjects we compared the internal consistency of standard CPI scales with that of CL and CS scales (Table 2). With very few exceptions, the KR20 coefficients of new scales are higher than those of standard scales.

The conclusion is that CL and CS questionnaires measure the same concepts as the standard scales in the questionnaire with 462 items of CPI, but contain much fewer items than CPI (CL has 249 items and CS, 213) and their scales have a better internal consistency than standard CPI scales.

 

Table 1. Linear correlation coefficients for questionnaires CPI, CL and CS

(N=1141)

Scale    CPI      CPI      CL       

            CL       CS       CS

Do       .934     .921     .988

Cs        .667     .669     .971

Sy        .868     .826     .962

Sp        .769     .642     .928

Sa        .629     .540     .971

In         .873     .854     .972

Em       .761     .716     .919

Re        .719     .711     .939

So        .791     .660       921

Sc        .958     .940     .983

Gi         .907     .907     1.000

Cm       .668     .639     .931

Wb      .884     .877     .989

To        .802     .751     .934

Ac        .617     .587     .979

Ai         .595     .449     .907

Ie         .888     .877     .960

Py        .709     .688     .873

Fx        .846     .846     1.000

FM      .816     .816     1.000

 

Table 2. KR20 internal consistency coefficients for scales in questionnaires CPI, CL and CS.

(668 males and 473 females)

 

Scale   CPI                                          CL                                           CS

Length     KR20                        Length     KR20                       Length   KR20

            M         F                                  M         F                                  M         F

Do       36        .766     .791                 20        .790     .829                 18        .778     .815    

Cs        28        .654     .690                 18        .750     .792                 14        .731     .776  

Sy        32        .674     .725                 18        .758     .814                 14        .725     .784 

Sp        38        .655     .700                 21        .752     .785                 17        .750     .775

Sa        28        .446     .584                 20        .808     .830                 14        .789     .810 

In         30        .616     .619                 19        .678     .737                 15        .692     .742  

Em       38        .534     .648                 18        .559     .635                 12        .582     .617 

Re        36        .657     .600                 24        .674     .633                 18        .658     .645 

So        46        .675     .682                 37        .796     .783                 23        .763     .762 

Sc        38        .810     .824                 33        .824     .832                 28        .810     .817  

Gi         40        .831     .828                 30        .826     .833                 30        .826     .833 

Cm       38        .497     .565                 24        .637     .632                 19        .616     .584 

Wb      38        .767     .812                 24        .789     .816                 22        .775     .805 

To        32        .566     .564                 23        .618     .624                 16        .593     .569 

Ac        36        .687     .694                 22        .742     .725                 19        .730     .726 

Ai         36        .577     .602                 26        .672     .716                 16        .628     .652 

Ie         42        .632     .681                 28        .714     .763                 21       .695     .757 

Py        28        .513     .582                 24        .693     .751                 14        .671     .728 

Fx        28        .573     .594                 14        .596     .619                 14        .596     .619 

FM      32        .484     .430                 15        .546     .490                 15        .546     .490 

 

 

                                                                     References

 

 

Gough, H.G. (1987), California Psychological Inventory Administrator's Guide, Consulting Psychologist Press, Palo Alto.

 

Pitariu, H.D., Albu, M. (1993), Inventarul Psihologic California: prezentare şi rezultate experimentale, Revista de Psihologie, nr. 3, 249-263.