Impact of BP-PBS on Incidents of Physical and Verbal Aggression
The frequency of incidents of bullying during 10-min observations over lunch recess for each target student and their composite peers is presented in . The 6 target students all displayed increasing trends in their frequency of aggression, with a combined mean of 3.1 incidents of aggression per baseline observation: 4 for Rob, 3.1 for Bruce, 2.8 for Cindy, 2.4 for Scott, 3.4 for Anne, and 3.1 for Ken. In School 1, Rob's baseline levels of problem behavior varied from 1 to 10 incidents and demonstrated an overall increasing trend. Bruce's baseline problem behavior was less variable, ranging from zero to five incidents, but with a similar increasing trend. In School 2, Cindy showed a slightly flatter increasing trend during baseline with a range of zero to five incidents over 23 observations. Scott's baseline was similar to that of Cindy with a slightly increasing trend, a range of zero to four incidents, and a mean of 2.4 incidents on a daily basis. In School 3, Anne showed a baseline of problem behavior ranging from one to six incidents and maintained a strong increasing trend over 30 observations. Ken's baseline ranged from one to five incidents, with a slightly lower mean and a more stable trend.
After the school staff received their training on BP-PBS, the study moved into the acquisition phase. During the acquisition phase, mean incidents of problem behavior per observation was 1.9 for the selected students, with a range of zero to four incidents and decreasing trends.
Once schools fully implemented the BP-PBS intervention, we observed reductions in the mean level of problem behavior per school day (0.9 incidents; 72% decrease from baseline), decreasing trends, and reductions in variability for all 6 targeted students. Mean aggression during the BP-PBS phase for Rob was 0.96 incidents per observation (a 76% reduction) with a gradually decreasing trend across the intervention phase. Mean incidents of problem behavior were 1.2, 1.3, 0.6, 0.8, and 0.4 for Bruce, Cindy, Scott, Anne, and Ken, respectively. These levels represent reductions of 63%, 53%, 79%, 76%, and 86%, respectively, from baseline means. The trends decreased steadily for all 6 students, and each student demonstrated reduced variability.
The Impact of BP-PBS on Victim and Bystander Response Probabilities
Each time a data collector recorded an incident of problem behavior, he or she also recorded the victim and bystander responses. These data are presented as conditional probabilities in . Bars indicate the pre and post response conditional probabilities for student in each school.
Overall, before the BP-PBS intervention, when an incident of problem behavior occurred, victims said “stop” 2% of the time, walked away 3% of the time, delivered a positive (reinforcing) response 19% of the time, delivered a negative (but presumably reinforcing) response 34% of the time, and delivered no response 43% of the time. Bystanders said “stop” 1% of the time, helped the victim walk away 2% of the time, delivered a positive response 39% of the time, delivered a negative response 18% of the time, and delivered no response 40% of the time.
The BP-PBS intervention was associated with increases in appropriate responses to problem behavior in all 3 schools. First, throughout the intervention phase, victims said “stop” 30% of the time (28% increase from baseline), walked away 13% of the time (10% increase), delivered a positive response 8% of the time (11% decrease), delivered a negative response 15% of the time (19% decrease), and delivered no response 34% of the time (9% decrease). Bystanders said “stop” 22% of the time (21% increase), helped the victim walk away 13% of the time (11% increase), delivered a positive response 17% of the time (22% decrease), delivered a negative response 8% of the time (10% decrease), and delivered no response 41% of the time (1% increase). Of particular note was the increased use of “stop” by both victims and bystanders, the decrease in victim delivery of a negative response (i.e., complaining, fighting back), and the decrease in bystander delivery of a positive response (i.e., cheering, laughing).
Fidelity of Implementation
We assessed fidelity of BP-PBS implementation by evaluating both student knowledge of the curriculum and staff adherence to program components. Student knowledge was examined by asking 10 students from a convenience sample to define the stop, walk, talk routines. We used the proportion of these 30 questions answered correctly as an index of student knowledge of the BP-PBS procedures. The results for three fidelity checks for School 1 were accuracy scores of 98%, 100%, and 93%. We assessed students in School 2 twice, and they scored 100% each time. We assessed students in School 3 once, and they scored 97%.
Staff self-reported fidelity of implementation results for each school. A total of 34 staff filled out the daily checklist during the study. Results indicate active use of BP-PBS procedures as staff reported a mean of 1.97 (range, 1.06 to 2.54) check-ins with chronic targets and instigators of problem behavior on a daily basis and delivered positive reinforcement to students for using the BP-PBS curriculum components a mean of 2.25 (range, 1.48 to 3.44) times per day. Together the data indicate that students were able to learn and retain the fundamental components of the BP-PBS curriculum, and that staff were able to implement the BP-PBS curriculum components throughout the study.
Social Validity
Twenty-five staff from all three schools completed the questionnaire on a six-point scale, with higher scores indicating a higher satisfaction with intervention components. The mean rating for “BP-PBS resulted in improved student behavior” was 4.4 (range, 3 to 6). Mean rating for “BP-PBS was worth the time and effort” was 4.7 (range, 3 to 6). Mean rating for “Would you recommend BP-PBS to others?” was 4.6 (range, 3 to 6), and the mean rating for “ease of implementation” was 5.5 (range, 3 to 6).