Inscape Publishing's DiSC model builds on the work of William Moulton Marston, who theorized that human behavior could be studied on a two-axis bipolar model according to people's perception of their work environment as favorable or antagonistic and their perception of being more or less powerful than their environment.

 Now there are two types of DiSC assessments:

• DiSC Classic profiles - most with 28-item response words.  Profile results are shown on graphs.  Traditional, basic, most familiear, solid, multi-purpose, still valid and reliable.
• Everything DiSC Application Library - with 79 item rating choice questions.  Profile results are shown on circles.  Each of these profiles and programs are supported by a topic-specific trainer kit.  These brand new products are state-of-the-art, highly reliable and valid, and yield the most consistent results.

DiSC vs. Myers-Briggs Comparison