Encyclopedia of Psychology and Law

Total MnSOST–R scores were significantly predic-

tive of sexual recidivism in the development sample,

as reflected by an area under the receiver operator

characteristics (ROC) curve of .77 (95% confidence

interval [CI] of .71 to .83). Total MnSOST–R scores

were equally predictive of sexual recidivism in the

development sample for rapists (ROC = .79) and

molesters (ROC =.75) and for minorities (ROC =.75)

and nonminorities (ROC =.77).

Reliability

Reliability studies have yielded positive results across

a variety of settings with varying degrees of training.

A Minnesota study involving a minimal 2-hour train-

ing session for 10 participants, who then scored the

same 11 cases by the end of the day, produced intra-

class correlation coefficients (ICCs) of .80 for relative

agreement and .76 for absolute agreement. A Florida

study involving an optimal 1.5-day training session

for 27 participants, who then scored the same 10 cases

over the next 3 months, yielded ICCs of .87 for rela-

tive agreement and .86 for absolute agreement. Two

Canadian studies produced interrater reliability coeffi-

cients of .80 and .83.

Validity

The MnSOST–R was validated in Minnesota with an

exhaustive sample of 220 sex offenders released from

prison in 1992 who met the same inclusion criteria

used in the development study. This sample was very

similar demographically to the development sample,

and sexual recidivism was defined in the same way.

Total MnSOST–R scores were significantly predictive

of sexual recidivism in this sample (ROC=.73, 95%

CI of .65 to .82).

Two validation studies were conducted in North

Dakota. The first sample included 182 incarcerated

sex offenders with an average time at risk of 8 years,

and the second sample included 271 probated sex

offenders with an average time at risk of 10 years. No

sex offenders were excluded in either of these sam-

ples. The MnSOST–R significantly predicted sexual

recidivism in the incarceration sample (ROC =.76,

95% CI of .66 to .85) and in the probation sample

(ROC =.75, 95% CI of .63 to .88).

Howard Barbaree, Calvin Langton, and their asso-

ciates conducted a validation study of the MnSOST–R

with two Canadian samples. Because the second, big-

ger sample largely subsumed the first sample, the

results of the second study are summarized here. That

sample of 354 sex offenders who were at risk for an

average of 5.9 years yielded a significant ROC =.70

for the MnSOST–R (95% CI of .62 to .77).

Darci Bartosh and her colleagues conducted a val-

idation of several risk assessment tools, including the

MnSOST–R, with a sample of 186 sex offenders in

the state of Arizona who were at risk for approxi-

mately 5 years. The resulting ROC =.58 missed the

threshold for statistical significance in this study,

though it was only slightly lower than the ROC values

for the other instruments assessed.

The North Dakota, Canadian, and Arizona studies

also assessed the Rapid Risk Assessment for Sexual

Offense Recidivism (RRASOR) and the STATIC–99,

and none of these studies identified significant differ-

ences between the tools. In fact, the scores were

clustered fairly tightly within each of these studies.

The respective ROC values for the MnSOST–R,

STATIC–99, and RRASOR were, respectively, .76,

.75, and .73 in the North Dakota prison study; .75, .78,

and .77 in the North Dakota probation study; .70, .64,

and .68 in the Canadian study; and .58, .64, and .63 in

the Arizona study.

Douglas L. Epperson

See alsoRapid Risk Assessment for Sexual Offense

Recidivism (RRASOR); Risk Assessment Approaches;

Sex Offender Risk Appraisal Guide (SORAG); Sexual

Violence Risk–20 (SVR–20); STATIC–99 and

STATIC–2002 Instruments

Further Readings

Epperson, D. L., Kaul, J. D., Goldman, R., Huot, S. M.,

Hesselton, D., & Alexander, W. (2005). Minnesota Sex

Offender Screening Tool–Revised Scoring Guidelines.

Retrieved January 2, 2007, from

http://www.psychology.iastate.edu/faculty/epperson/

MnSOST-RManual12-22-2005.pdf

Epperson, D. L., Kaul, J. D., Huot, S. M., Goldman, R., &

Alexander, W. (2003). Minnesota Sex Offender Screening

Tool–Revised (MnSOST–R) Technical Paper:

Development, validation, and recommended risk level cut

scores. Retrieved January 2, 2007, from

http://www.psychology.iastate.edu/faculty/epperson/

TechUpdatePaper12-03.pdf

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