Split-half reliability based on continuous scores.

The split-half reliability scores for the Form G MBTI^® instrument are as follows¹:
EI = 82;  SN = 84;  TF = 83;  JP = 86

The split-half reliability scores for the TPPI are as follows²:
EI = 87;  SN = 93;  TF = 91;  JP = 85

Split-half reliability based on dichotomous scores.

      EI  SN  TF  JP

For the MBTI^® instrument³: Phi  61 54 49 73

For the TPPI⁴: Phi  77 82 78 71

Validity Measures

Correlations between the MBTI^® instrument and the TPPI⁵:

EI = 76;  SN = 71;  TF = 78;  JP = 73

Summer/99

1 Based on the total Form G data bank (n=32,671) and derived from the product-moment correlation of X and Y continuous scores with Spearman-Brown prophecy formula correction. P. 166 of Manual: A Guide to the Development and Use of the Myers-Briggs Type Indicator® instrument.

2Sample of 420 (180 grade 11 and 12 high school students' lower/middle class school; 70 government office workers' mostly professional; 170 municipal workers' broad collection of backgrounds) and derived from the Spearman's rho of X and Y continuous scores with Spearman-Brown prophecy formula correction.

3Comparison of internal consistency of type categories using estimates from Phi Coefficients, all corrected using the Spearman-Brown prophecy formula. P. 171 of Manual: A Guide to the Development and Use of the Myers-Briggs Type Indicator® instrument. Based on 100 grade 12 male students.

4Comparison of internal consistency of type categories using estimates from Phi Coefficients, all corrected using the Spearman-Brown prophecy formula. Based on previously described sample of 420.

5Everyone in the sample of 420 completed both the MBTI® instrument Form G and the TPPI, therefore the Pearson Product Moment correlations are between the continuous scores of both these instruments.

*Myers-Briggs Type Indicator and MBTI are registered trademarks of Consulting Psychologists Press, Inc.