1978 two Jungian analysts, June Singer and Mary Loomis, initiated
an innovative experiment with approximately 200 people. Being deeply
concerned about the lifelong process of individuation, they were
skeptical of any assumption that implied individuals remained the
same throughout their lifetime. Consequently, they decided to empirically
test the viability of the bipolar assumption underpinning the existing
Jungian Type inventories (The Myers-Briggs Type Indicator and the
Grey-Wheelright Type Inventory). Their experiment is described in
detail in the Journal of Analytical Psychology (1980). The
experiment involved creating new versions of each of these inventories
by removing the forced-choice, either/or structure and, without
changing the text of the items, placing each item on a Likert 5-point
scale. Subsequently, they administered the original and the modified,
non-bipolar versions to two groups totaling approximately 200 people.
core difference between the original and the modified version was
that the original assumed the presence of the bipolar condition,
whereas the modified version did not. The modified version did not
preclude showing the bipolar condition, if it was actually
present. This allowed the presence or absence of the condition to
become an empirically testable question rather than an untested
assumption. Comparison of the results generated by the original
and alternative versions of each of the inventories revealed that
the forced-choice structure was creating inappropriate classifications
of the dominant Type capacity in over 50% of the cases and of the
least developed Type capacity in 40% of the time.
startling results were far in excess of what could be reasonably
expected if the forced choice structure (which was based on the
bipolar assumption) was only a minor or insignificant issue. These
results provided a compelling incentive to create a new Type inventory.
When it was created in 1979, they called the new instrument the
Singer-Loomis Inventory of Personality(SLIP).Over the
course of the next four years, it was evolved from Version 1 to
Version 3. Consulting psychologists published Version 3 from 1984-1995.
early 1996, Drs. Singer and Loomis purchased the copyright from
Consulting Psychologists Press and established an arrangement whereby,
Drs. Elizabeth and Larry Kirkhart became the copyright holders and
publishers of the Inventory and all associated materials. In March
1996, Elizabeth and Larry created a new organization, Moving Boundaries
inc, dedicated to the further development of Jungian Type concepts
and Jungian psychology in clinical and human resource development
(HRD) areas. Moving Boundaries follows and supports American Psychology
Association guidelines on the ethical and professional use of psychological
With the aid of professional colleagues and three
Jungian analysts, June Singer, Mary Loomis and Martha Newell, Elizabeth
and Larry Kirkhart thoroughly revised the instrument and created
Version 4 in March 1996. At that time the inventory was renamed
the Singer-Loomis Type Deployment Inventory(SL-TDI).
In addition to changing existing items and situations, major changes
were made in how the results of the Inventory were compiled and
represented. The creation of Version 4 emphasized strengthening
technical performance, increasing user friendliness and enhancing
usability of the results.
the new version was available, field-testing was initiated immediately.
Moving Boundaries now has over 3300 protocols in its database. A
Cronbach Alpha analysis has been performed on 2684 cases. This analysis
indicated that Version 4 Alpha scores were even higher than Version
3 on 14 of 16 outcome measures and that the SL-TDI meets or exceeds
the levels of reliability expected of a personality inventory.
A summary of an independent
study by members of the Psychology Department
at Texas A&M shows similar results.