New Index

Recent research indicates that a new way of scoring the DIT is most often better. Using the same data as before (the same stories, items, same subjects' ratings and rankings) the new index (called New Index, or "N") generally produces more powerful data trends than the usual index, "P". Researchers are encouraged to analyze data both with the P and the N index.

The Scoring Service from the Center will now provide researchers with all the previous scores, along with N2, the new index. Information on N2 is provided in the DIT-2 GUIDE. For an extended discussion of validity trends of the former indices (P and D) are compared with theN2 index. For an extended paper, see Rest, Thoma, Narvaez, & Bebeau (1997). Alchemy and beyond: Indexing the Defining Issues test. Journal of Educational Psychology, 89 (3), 498-507.

Summary Comparisons among P, D, and N2 indices

1. Gains in 10-year longitudinal study (trends expressed in terms of matched pair t-tests):
   P: 6.09 D: 6.81 N2: 7.82
2. Correlations with education (r from 4 studies):
   P: 0.62 D: 0.63 N2: 0.64
3. Correlations with moral comprehension (r from 2 studies):
   P: 0.53 D: 0.52 N2: 0.55
4. Correlations with life experiences (r from 4 variables):
   P: 0.58 D: 0.46 N2: 0.59
5. Gains in moral education interventions (matched pair t-test over 4 studies):
   P: 6.28 D: 5.22 N2: 6.50
6. Correlations with attitudes and behavior measures (r over 7 variables):
   P: 0.49 D: 0.40 N2: 0.51
7. Internal reliability (average Cronbach alpha over 2 studies, n=1926):
   P: 0.77 D: 0.78 N2: 0.77
8. "Most powerful index" in 27 comparisons (sum of first places):
   P: 5.50 D: 5.00 N2: 16.5 (P and N2 are tied in one comparison)

Free Rescoring Old Data by the Center

If you wish to have N scores for "old" data (i.e. data already analyzed with the P score and the other usual scores), the Center will provide this additional analysis free of charge.

If the Center has provided you with diskettes for previously-scored data, return the diskette(s) along with a self-addressed label or envelope (at least 9 by 12”), and we will re-score your previous data, providing a hard copy on paper and the new files on the diskette. Send in as many diskettes as you want analyzed and the new files will be put on each diskette.

If you scored your data by hand as a student dissertation earlier than July 1995 and wish to have N2 scores for this data, send in a diskette with the raw data (the ratings and rankings) according to the format listed in Table 2.1 in the GUIDE. In a cover letter, indicate the story order that you used (Heinz, Prisoner, Newspaper, Doctor, Webster, Students) or (Heinz, Students, Prisoner, Doctor, Webster, Newspaper). Please note that the data must be entered exactly in the indicated columns and that the file must be free of control characters (i.e., it must be a stripped, pure ASCII file), on a 31/2” diskette , and be IBM compatible. Send in a self-addressed label or envelope (at least 9 by 12”).

We can provide this scoring service free only if raw data is provided in the format that our computers recognize. It would be helpful to us if you also describe the sample that the data is from (in terms of age/education, sex, region of country, and approximate date of data collection). Also eventually we would be very interested in hearing about your experience with the new index: whether or not it produced better trends than the previous index.

If you wish to have the longer article [Rest, Thoma, Narvaez, & Bebeau (1997)] on the new index, please indicate that in a cover letter so that we can include that in the return mailing.