A universal classroom-based preventive intervention in combination with an indicated preventive intervention, both of which are designed to prevent aggression.

The Change in Pictorial Scale of Perceived Competence and Social Acceptance for Young Children assesses the student's perceived competence in the domains of peer acceptance. Items on this instrument present two pictorial alternatives, one of a child displaying high competence in the social acceptance domain and one that depicts less competence. Students were asked which pictorial plate was most like him/her. After making that decision, the student is then asked if the chosen picture is "really true for me" and "sort of true for me." Each item is scored on a 4-point scale, 4 would be the most competent and 1 would designate the least competent. The mean of the items was used in the outcome analyses.

This scale assesses teacher sense of self-efficacy in the instructional and classroom behavior management domains. We assessed two distinct dimensions of teachers' perceived self-efficacy that reflect skills uniquely associated with the strategies included in the two interventions. The Behavior Management Self-Efficacy Scale (Main and Hammond 2008) included 14 items regarding classroom behavior management (e.g., I am able to use a variety of behavior management techniques; α= 0.92). The Social-Emotional Learning Efficacy Scale (Domitrovich, et al., 2016) included 8 items which focused on teachers' perceived efficacy to promote social-emotional skills in students (e.g., I am able to teach children to show empathy and compassion for each other; α= 0.91). For each scale, item responses were on a 5-point Likert-type scale and were averaged. For both subscales the minimum score was 1 and maximum was 5, with higher scores indicating greater efficacy.

The Maslach Burnout Inventory assesses how frequently teachers experience feelings of burnout in the work place. Teachers completed the Maslach Burnout Inventory (MBI;Maslach et al. 1997) at pretest and post-test. One scale was used in the analyses: emotional exhaustion (9 items, e.g., I feel used up at the end of the workday, α=0.94). Responses were rated on a 7-point scale from never to every day with higher scores indicating greater emotional exhaustion (i.e., greater burnout). For this subscale, the minimum score was 1 and maximum score was 7. Therefore, low scores on emotional exhaustion were desired.

The combination of PATHS to PAX with the Incredible Years child and parent groups.

PATHS to PAX and the Incredible Years: A universal classroom-based preventive intervention in combination with an indicated preventive intervention, both of which are designed to prevent aggression.

Total of all reporting groups

Baseline characteristics of enrolled students and enrolled teachers are represented on different rows.

Baseline characteristics of enrolled students and enrolled teachers are represented on different rows.

Baseline characteristics of enrolled students and enrolled teachers are represented on different rows.

Baseline characteristics of enrolled students and enrolled teachers are represented in the same row.

Student adaptation to classroom task demands are rated by teachers over the last 3 weeks on a 6-point frequency scale (1 = almost never to 6 = almost always). The domains include authority acceptance (α= 0.96; min=1; max=6) and readiness to learn (α= 0.97; min=1; max=6). Authority acceptance items include classroom rule compliance, & readiness to learn items reflect attentive classroom behaviors (e.g. stays on task). The mean of the teacher ratings across the items making up each of these subscales was used in the outcome analyses. Higher scores on both subscales reflect greater adaptation.

Students enrolled within participating schools who were assessed at baseline. Only students were included in this part of the data collection.

Classroom observations were completed by independent observers. The behaviors observed were on-task and physical aggression. Behaviors were observed in 10 second intervals and were recorded as present if they occurred at least once during a 10 second interval. The per interval on-task and physical aggression scores could range from 0-1, with 0 signifying the behavior was not observed and 1 signifying the behavior was observed. The on-task and physical aggression scores used in the analyses were the average score across all of the 10-second intervals the student was observed.

Students enrolled within participating schools who were assessed at baseline. Only students were included in this part of the data collection.

Individual students were read aloud the names of the other students in the classroom. The student being interviewed was asked if they knew the named student. The student was then asked whether the peer nomination descriptors fit the named student (Do you like [student]?, Do you play with [student]?, and Is (s)he one of your best friends?). The student's summary score reflected the mean percentage of nominations received across the 3 items (α=0.91). A higher percentage reflects a student received a greater number of nominations from classmates.

Students enrolled within participating schools who were assessed at baseline. Only students were included in this part of the data collection.

Items on this instrument present two pictorial alternatives, one of a child displaying high competence in the social acceptance domain and one that depicts less competence. Students were asked which pictorial plate was most like him/her. After making that decision, the student is then asked if the chosen picture is "really true for me" and "sort of true for me." Each item is scored on a 4-point scale, 4 would be the most competent and 1 would designate the least competent. The mean of the items was used in the outcome analyses. The coefficient alpha for the mean score was 0.71.

Students enrolled within participating schools who were assessed at baseline. Only students were included in this part of the data collection.

The Behavior Management Self-Efficacy Scale (Main and Hammond 2008) included 14 items regarding classroom behavior management (e.g., I can manage a class very well; α= 0.918; min=1; max=5). The Social-Emotional Learning Efficacy Scale (Domitrovich, et al., 2016) included 8 items which focused on teachers' perceived efficacy to promote social-emotional skills in students (e.g., I am able to teach children to show empathy; α= 0.909; min=1; max=5). For each scale, item responses were provided on a 5-point Likert-type scale, & were averaged, higher scores indicating greater efficacy.

Teachers enrolled in within participating schools who were assessed at baseline. Only teachers were included in this part of the data collection.

Teachers completed the Maslach Burnout Inventory (MBI;Maslach et al. 1997). One scale was used in the analyses: emotional exhaustion (9 items, e.g., I feel used up at the end of the workday, α=0.937; min=1; max=7). Responses were rated on a 7-point scale from never to every day and to create scale scores such that higher scores indicated greater emotional exhaustion (i.e., greater burnout). Therefore, low scores on emotional exhaustion were desired.

Teachers enrolled within participating schools who were assessed at baseline. Only teachers were included in this part of the data collection.

Change in Teacher Observation of Classroom Adaptation between pre-test and post-test, 6 months after the pre-test. Student adaptation to classroom task demands are rated by teachers over the last 3 weeks on a 6-point frequency scale (1 = almost never to 6 = almost always). The domains include authority acceptance and readiness to learn. Authority acceptance items include compliance with classroom rules, and readiness to learn items reflect attentive classroom behaviors (e.g. stays on task). The mean of the teacher ratings across the items making up each of these subscales was used in the outcome analyses. The minimum score for both the authority acceptance and readiness to learn subscales was 1 and maximum score was 6. Higher scores on both subscales reflect greater adaptation.

Students enrolled in participating schools with parental consent to participate in the trial who were teacher rated at baseline and post-test.

Students are asked to nominate fellow students in terms of who they like, play with, and perceive as friends. Individual students were read aloud the names of the other students in the classroom. The student being interviewed was asked if they knew the named student. The student was then asked whether the peer nomination descriptors fit the named student (Do you like [student]?, Do you play with [student]?, and Is (s)he one of your best friends?). The student's summary score reflected the mean percentage of nominations received across the 3 items. A higher percentage reflects a student received a greater number of nominations from classmates.

Students enrolled within participating schools with parental consent to participate in the trial who were interviewed at baseline and at post-test.

The Change in Pictorial Scale of Perceived Competence and Social Acceptance for Young Children assesses the student's perceived competence in the domains of peer acceptance. Items on this instrument present two pictorial alternatives, one of a child displaying high competence in the social acceptance domain and one that depicts less competence. Students were asked which pictorial plate was most like him/her. After making that decision, the student is then asked if the chosen picture is "really true for me" and "sort of true for me." Each item is scored on a 4-point scale, 4 would be the most competent and 1 would designate the least competent. The mean of the items was used in the outcome analyses.

Students enrolled in participating schools with parental consent to participate in the trial who were interviewed at baseline and post-test.

This scale assesses teacher sense of self-efficacy in the instructional and classroom behavior management domains. We assessed two distinct dimensions of teachers' perceived self-efficacy that reflect skills uniquely associated with the strategies included in the two interventions. The Behavior Management Self-Efficacy Scale (Main and Hammond 2008) included 14 items regarding classroom behavior management (e.g., I am able to use a variety of behavior management techniques; α= 0.92). The Social-Emotional Learning Efficacy Scale (Domitrovich, et al., 2016) included 8 items which focused on teachers' perceived efficacy to promote social-emotional skills in students (e.g., I am able to teach children to show empathy and compassion for each other; α= 0.91). For each scale, item responses were on a 5-point Likert-type scale and were averaged. For both subscales the minimum score was 1 and maximum was 5, with higher scores indicating greater efficacy.

Consenting teachers assigned to Kindergarten - second grade in participating trial schools who were assessed at baseline and post-test.

The Maslach Burnout Inventory assesses how frequently teachers experience feelings of burnout in the work place. Teachers completed the Maslach Burnout Inventory (MBI;Maslach et al. 1997) at pretest and post-test. One scale was used in the analyses: emotional exhaustion (9 items, e.g., I feel used up at the end of the workday, α=0.94). Responses were rated on a 7-point scale from never to every day with higher scores indicating greater emotional exhaustion (i.e., greater burnout). For this subscale, the minimum score was 1 and maximum score was 7. Therefore, low scores on emotional exhaustion were desired.

Consenting teachers assigned to Kindergarten - second grade in participating trial schools who were assessed at baseline and post-test.

Universal classroom-based preventive intervention designed to reduce aggression.

PATHS to PAX: A universal classroom-based preventive intervention designed to prevent aggression.

The combination of PATHS to PAX with the Incredible Years child and parent groups.

PATHS to PAX and the Incredible Years: A universal classroom-based preventive intervention in combination with an indicated preventive intervention, both of which are designed to prevent aggression.