Validation
The Validation Process
Extended DISC International is a proud provider of validated high-class instruments. Everyone representing Extended DISC must follow the ethics generally accepted in their line of business and we fully follow the Code of Fair Testing Practices. Furthermore, no one in the industry has a more extensive validation process than us.
Our annual validation report summarizes the study of the Extended DISC® instrument and the four key dimensions which it assesses (Dominance, Influence, Steadiness and Compliance). Reliability and validity characteristics of the Extended DISC® System are analyzed by using various statistical methods.
Summary of Validation Report 2008
Research population
The population was collected from the users of the Extended DISC® System, representing all nationalities the company (Extended DISC International) has representation offices in. The population also represents all the age groups, genders, organization types and levels and races in the same ratio it is designed to be used.
The total population used for the research was 63.684. The size of the main comparison population (2007 validation population) was 57.955.
The main language versions of Extended DISC® Personal Analysis for the study were (the language codes used in this study):
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Reliability and Validity of Extended DISC® Personal Analysis
Internal consistency. Internal consistency is a measure based on the correlations between different items on the same test (or the same subscale on a larger test). It measures whether several items that propose to measure the same general construct produce similar scores. Internal consistency is usually measured with Cronbach's alpha, a statistic calculated from the pairwise correlations between items. Internal consistency ranges between zero and one. A commonly-accepted rule of thumb is that an a of 0.6-0.7 indicates acceptable reliability, and 0.8 or higher indicates good reliability. High reliabilities (0.95 or higher) are not necessarily desirable, as this indicates that the items may be entirely redundant.
The global Cronbach’s alpha for Extended DISC® Personal Analysis version 2008 (2007) was:
| D | .84 (.84) |
| I | .82 (.82) |
| S | .84 (.84) |
| C | .79 (.79) |
The results prove that the instrument continues having a very high validity.
