**2.1 Sample**

204 Complementary Pediatrics

the schools. These studies use varying definitions for online and offline bullying and/or focus on regional or convenience samples. Furthermore, rates in non-school environments are not reported. Little has been reported in terms of bullying perpetration across environments also. Of note, Wang and colleagues (Wang et al., 2009) report that among 6- 10th graders nationally, 8% bully others online, 27% bully others socially, 37% bully verbally, and 13% bully others physically while at school. Online bullying is treated as a different *type* of bullying however; such that, for example, social bullying that occurs online is imperfectly measured. Importantly too, data are lacking about how the bullying *experience* may differ online versus offline. No data have been presented to compare relative rates of distress for bullying that occurs online versus offline. It also has been posited that a unique aspect of online bullying is the potential for anonymity; this assumes that all victims know their offline bullies. No research has examined however, whether this is a valid assumption. Even less has been reported about unwanted sexual experiences online and offline. Ybarra and colleagues (Ybarra, Espelage, & Mitchell, 2007b) report overlaps in victimization for harassment and unwanted sexual experiences online; they do not report however, the relative rates of unwanted sexual experiences online and offline. To our knowledge, no other studies have reported relative rates of online and offline unwanted sexual solicitation

To address these gaps in the literature, we report data from the Growing up with Media study, a national survey of over 1,000 youth. Findings have implications for public policy

The Growing up with Media study is a longitudinal survey examining the associations between exposure to violent media - particularly new media (e.g., the Internet) - and violent behavior. Wave 1 data were collected August-September, 2006 with 1,588 youth-caregiver pairs; data were collected again November, 2007 - January 10, 2008 [Wave 2, (n=1,206)] and August - November, 2008 [Wave 3, (n=1,159)]. The survey protocol was reviewed and approved by the Centers for Disease Control and Prevention Institutional Review Board

The sample was obtained from the Harris Poll Online (HPOL) opt-in panel (Harris Interactive, 2006), which is comparable to random telephone samples of adult populations once appropriate sample weights are applied (Berrens, Bohara, Jenkins-Smith, Silva, & Weimer, 2003; Berrens, Bohara, Jenkins-Smith, Silva, & Weimer, 2004; Schonlau et al., 2004; Taylor, Bremer, Overmeyer, Siegel, & Terhanian, 2001). Recruitment was balanced on youth age and sex. Participants were recruited through an email contact with randomly identified adult HPOL members who had previously indicated a child lived in the household. Adult respondents (one per household) were required to be equally or more knowledgeable than other adults in the home about the youth's media use, and to provide consent for their participation and permission for their child's participation. Youth participants were required to be 10-15 years old, read English, live in the household at least 50% of the time, have used the Internet in the last 6 months, and provide assent to

initiatives as well as school and other community-based intervention efforts.

in the general population of youth.

**2. Methods** 

(IRB).

participate in research.

Although parallel questions of bullying online and offline were added at Wave 2, it was not until Wave 3 that measures of perpetration and distress were added. To fully answer the research questions posed, the current analyses are restricted to Wave 3. The baseline survey response rate, 26%, was within the expected range of similar online surveys (Cook, Heath, & Thompson, 2000; Kaplowitz, Hadlock, & Levine, 2004).

To maximize data, respondents were invited to take part in the Wave 2 and Wave 3 surveys irrespective of their participation at previous Waves. Response rates were 76% and 73% of baseline participants at Wave 2 and Wave 3, respectively. Survey participants in subsequent Waves were similar to participants in Wave 1 and also to the national population (See table 1 below). For example, using weighted data, 49% of the sample was male at Wave 3, and 49% was male at Wave 1. Seventy-three percent identified as White race at Wave 3 and 71% at Wave 1. Twenty-five percent lived in a household with an annual income of \$35,000 or less at Wave 3 versus 26% at Wave 1.


Table 1. A comparison of demographic charactaeristics of respondents across waves

#### **2.2 Measures**

Respondents were asked about bullying *victimization* as well as *perpetration* using Olweus' definition of bullying (Olweus, 1994): "We say a young person is being bullied or harassed when someone else or a group of people **repeatedly** hits, kicks, threatens, or says nasty or unpleasant things to them. Another example is when no one ever talks to them. These things

Comparisons of Bully and Unwanted Sexual

**3. Results** 

**3.1.1 Bully victimization** 

Every day / almost every

**3.1.2 Bully perpetration** 

Every day / almost every

Frequency School

Frequency School

Experiences Online and Offline Among a National Sample of Youth 207

Missing data and "refused" responses were imputed using best-set regression (StataCorp, 2008). To reduce the likelihood of imputing truly non-responsive answers, participants were required to have valid data for at least 85% of the survey questions asked of all youth. Eleven respondents did not meet this criterion and were dropped from the Wave 1 sample;

Statistical comparisons across environments cannot be made because categories are not

Environment

Table 2. A comparison of 1-year bullying victimization rates across environments

13% were bullied only online; and 28% were bullied both at school and online

Environment

Table 3. A comparison of 1-year bullying perpetration rates across environments

(n=1,149) % (n)

Internet (n=1,149) % (n)

day 1.3 (15) 0.3 (4) 0.4 (1) 0.9 (3) 0.3 (3) Once or twice a week 4.0 (43) 0.3 (5) 0.5 (6) 1.7 (16) 1.5 (13) Once or twice a month 3.2 (46) 1.9 (22) 1.7 (13) 1.1 (15) 1.9 (22) Less often 22.1 (254) 12.3 (150) 9.5 (73) 7.8 (88) 10.8 (114) Never 69.4 (791) 85.3 (968) 88.2 (713) 89.2 (1027) 85.6 (997) a Restricted to youth who sent and received text messages at least once in the past year (70%, n=806)

Overall, 40% of youth reported some bully victimization in the past year. Rates across environments are shown in Table 2. An examination of the school-online overlap suggests that most of these youth were bullied at school exclusively: 59% were bullied only at school;

> Internet (n=1,149) % (n)

day 0.3 (5) 0.06 (2) 0.3 (2) 0.03 (1) 0.4 (3) Once or twice a week 1.3 (13) 0.6 (7) 0.9 (6) 0.9 (8) 1.2 (11) Once or twice a month 1.7 (22) 0.8 (15) 1.0 (11) 0.3 (8) 1.2 (15) Less often 10.4 (107) 4.7 (47) 3.4 (25) 3.0 (34) 3.4 (44) Never 86.4 (1002) 93.7 (1078) 94.3 (762) 95.8 (1098) 93.8 (1076) a Restricted to youth who sent and received text messages at least once in the past year (70%, n=806)

Cell phone text messaginga (n=806) % (n)

Cell phone text messaginga (n=806) % (n)

To and From school (n=1,149) % (n)

To and From school (n=1,149) % (n)

Somewhere else (n=1,149) % (n)

Somewhere else (n=1,149) % (n)

17 were dropped from the Wave 2 and 10 from the Wave 3 samples.

(n=1,149) % (n)

exclusive; youth can be represented in multiple categories.

**3.1 One-year prevalence rates across environments**

can happen at school, online, or other places young people hang out. It is **not** bullying when two young people of about the **same strength** fight or tease each other. How often has this happened to you in the following environments?): 1) at school, 2) on the Internet, 3) on cell phones through text messaging, 4) on the way to and from school, and 5) somewhere else. For each environment, response options were: every day / almost every day; once or twice a week; once or twice a month; less often than once a month; never; and decline to answer.

Youth who reported bullying victimization in at least one environment were asked two follow up questions. First, these youth were asked to indicate how they felt when they were bullied in each environment, when thinking about the most serious incident. Responses were captured on a 5-point scale: not at all upset; somewhat upset; upset; very upset; extremely upset; and decline to answer. Second, youth were asked whether they knew their bully: "By "know" we mean you can recognize the person or you know who they are". Response options were: yes, no, not sure, and decline to answer.

Unwanted sexual experiences also were measured using parallel items for experiences when online, and experiences when at school. Note that other environments, including on the way to and from school, and 'somewhere else' were not queried. Text messaging-based experiences were queried, but using different measures and therefore are not included in the current analyses. Items were based upon those included in and referred to as "unwanted sexual solicitation" in the Youth Internet Safety Surveys (Finkelhor, Mitchell, & Wolak, 2000; Wolak et al., 2006). We choose to call these experiences "unwanted sexual experiences" to avoid connotation that these youth were necessarily solicited for sex. Youth endorsing at least one of the following questions were classified as having an unwanted sexual experience: 1) Someone tried to get me to talk about sex when I did not want to; 2) Someone asked me for sexual information about myself when I did not want to tell the person, e.g., really personal questions, like what my body looks like or sexual things I have done; 3) Someone asked me to do something sexual that I did not want to do. Response options were: everyday/almost every day; once or twice a week; once or twice a month; a few times a year; less than a few times a year; never; and decline to answer. Perpetration was asked solely for the online environment. Similarly, distress was only queried for youth reporting victimization online. Given that the focus of the current paper is comparisons across environments, these data are not reported.

#### **2.3 Data cleaning and statistical analyses**

Data cleaning indicated that 18 youth were likely 9 years of age, and 12 youth were 16 years of age at Wave 1. To maximize the amount of data; and because caregivers did not know the eligibility criteria (and, therefore, were unlikely to have misreported their child's age purposefully), these youth are included in the analyses.

Data were weighted statistically to reflect the population of adults with children aged 10-15 years old in the U.S. in 2006 (when the sample was first recruited) according to adult age, sex, race/ethnicity, region, education, household income, and child age and sex.(Bureau of Labor Statistics & Bureau of the Census, 2006) Adults were the weighting target as they were the ones first recruited into the survey. Survey sampling weights also adjust for adult respondents' self-selection into the HPOL (Berrens et al., 2003; Berrens et al., 2004; Schonlau et al., 2004; Taylor et al., 2001) as well as any differential follow-up of youth participants over time.

Missing data and "refused" responses were imputed using best-set regression (StataCorp, 2008). To reduce the likelihood of imputing truly non-responsive answers, participants were required to have valid data for at least 85% of the survey questions asked of all youth. Eleven respondents did not meet this criterion and were dropped from the Wave 1 sample; 17 were dropped from the Wave 2 and 10 from the Wave 3 samples.

Statistical comparisons across environments cannot be made because categories are not exclusive; youth can be represented in multiple categories.
