About Developmental Therapy Teaching

DTT Effectiveness

Developmental Therapy in Brief This is a program that works!

Nationally and internationally, thousands of students and teachers have used DTT over the past four decades with demonstrated effectiveness and sustained results after repeated studies. Studies of DTT effectiveness can be grouped into two general streams of effort: outcomes for students with ED/BD, and proficiencies of their teachers after receiving DTT inservice training.

Among the research studies submitted to the U.S. Department of Education, Joint Dissemination Review Panel (JDRP) and Program Effectiveness Panel (PEP), DTT received three separate validations from the National Diffusion Network (NDN) as “An educational program that works” (U.S. Department of Education, 1996). These include JDRP approval #7563, 1975; JDRP approval #81-19, 1986; and PEP revalidation, 1996. Research evidence of DTI effectiveness also resulted in a Significant Achievement Award from the American Psychiatric Association (1993) In recognition of an innovative and well-researched program … resulting in outstanding clinical care and professional development.

Three follow-up DTT studies with similar results are summarized briefly below. One examined students’ responses to DTT intervention. Another studied teachers’ responses to DTT inservice training, and the third explored changes in teachers’ behavior management after independent use of the DTT CD-ROM program, PEGS for Teachers.

Students Gain Competencies in Response to DTT Intervention

A stratified sample of 58 students ages 2 to 12 at five sites was obtained from a pool of 22 replication sites in communities of low, middle and upper/middle economic characteristics. The program locations had distinct geo-cultural characteristics: rural, migrant, urban, and Caribbean. A pre/post repeated measures design was used with students’ DTT developmental objectives as the unit of inference.

Measures of developmental assessment were obtained using the Developmental Teaching Objectives and Rating Form-Revised (DTORF-R). For the group, average DTT intervention was 6 months; range, 2 to 15 months. Dependent t-tests of gains scores, using 95% confidence levels and Friedman’s point-bi-serial rm indicated significant gains with a large effect size
(M = 10.05, SD = 7.00, t = 10.94, p = .0001, rm =.82).

Gains occurred in each developmental domain: Behavior (M = 13.21, SD = 16.11, t = 6.24, p (.0001); Communication (M = 11.98,SD = 16.03, t = 5.69, p <.0001); Socialization (M = 8.65, SD = 12.86, t = 5.13, p<.0001); and Cognition (M =8.50, SD = 9.39, t = 6.89, p<.0001).

Similar results were found when scores were analyzed separately by site and by program type: Tier 1, full inclusion (13 students, M = 12.14, SD = 8.56, t = 5.12, p<.001); Tier 2, partial inclusion (35 students, M = 10.03, SD = 6.76, t = 5.12, p<.0001); and Tier 3, intensive intervention (10 students, M = 7.40, SD = 5.04, t =4.64, p <.001). Significant t-values also were obtained for gains by gender and by age groups and in settings with diverse geo-cultural and economic characteristics. Although the sample was small, the findings add support to the cumulative evidence that DTT is successful in three levels of intervention, various education settings with differing socioeconomic characteristics, and with male and female students from early childhood through middle school.

Teachers Increase Their Classroom Skills With DTT Inservice

The effectiveness of DTT inservice training was reported in a study of 45 teachers of students with ED/BD at five schools. Participants received year long DTT training intermittently at their own school sites. They were rated pre-and post-training for proficiency using DTT in their classrooms. Proficiency was measured with the Developmental Teaching Rating Inventory of Teacher Skills (DTRITS). Before training began, the teachers with no prior teaching experience achieved a mean pre-training score 170, while experienced teachers had a mean score >70.

For the group, the post-training DTRITS mean score was 86.42 (SD = 9.43) indicating overall performance was at the Effective criterion level for DTT. Repeated measures were available for 20 of the participants in a follow-up study. Directly after training, the mean DTRITS score for this subgroup was 83.25 (SD = 12.16). After 16 months, their proficiency remained stable, and there was no significant loss in performance (M = 84.80, SD = 9.82, t = .55, p = .59). At a third rating for 14 of these same teachers who remained in the group approximately 16 months later, significant gains in proficiency occurred (M= 90.07, SD = 8.00, t = 4.42, p<.000), suggesting that these teachers were able to expand their DTT skills independently after the basic training.

This study supports four claims of DTT inservice program effectiveness (a) teachers achieved proficiency and sustained it after participating; (b) inexperienced teachers reached proficiency standards, and experienced teachers increased their proficiency; (c) teachers reached a passing level of proficiency or better within 30 contact hours of training; and (d) teachers’ age, years of prior teaching, and academic achievement were not correlated with DTT proficiency, but area of prior training was related.

To explore the question of whether the gains these teachers made were attributable to the experience of teaching students with ED during the training, a post hoc cohort analysis was conducted. Post-training scores for 12 teachers with no previous teaching experience (Group 1) were compared after the first year with pre-training score of 12 teachers who had one year of previous teaching experience (Group 2). Group 1 had a post- training mean of 75, and Group 2 had a pre-training mean of 55 (t = 1.81, p<.05, one-tailed), suggesting that their achievement was not attributable to experience alone.

Teachers’ Behavior Management Improves Significantly With PEGS for Teachers CD-R Simulated Practice

Teachers in 35 DTI classrooms were observed and rated on a modified DTRITS observation instrument that focused on behavior management and student responses. Teachers were observed before and after they participated independently using the DTT interactive CD-ROM program for practice in positive behavior management, PEGS for Teachers. Gains in behavior management occurred after independent use of the program for 3 hours cumulatively over 2 weeks. Behavior management scores increased 41% for 12 early childhood teachers , 41% for 12 elementary teachers, and 42% for 11 secondary teachers. Dependent t-values indicated that these gains were statistically significant (t-values of 2.53, 3.19, and 1.91 respectively) and the magnitude of effect size was large (r values of .57, .69, and .52 respectively).

Students negative responses to the teachers decreased by 64% for early childhood teachers, 55% for elementary teachers, and 28% for secondary teachers. These decreases in students’ negative behaviors were significant for early childhood teachers (t = 1.76, rm = .44, a moderate effect size) and for elementary teachers (t = 2.54, rm = .58, a large effect size). For secondary teachers, the gains were not statistically significant.

Results of this study suggest that the DTT behavior management CD-ROM materials, PEGS for Teachers, can improve classroom practices of teachers. It also indicates that students’ negative behaviors in the classroom will decline during a corresponding two-week period.