|Statistics in Brief||October 1995|
Mary Jo Nolin,
This report presents information from a national survey of 6th- through 12th-grade students on student strategies to avoid harm at school. The data are from the 1993 National Household Education Survey (NHES:93) conducted by Westat for the National Center for Education Statistics. This report is based upon the responses of the 6,504 students in grades 6 through 12 who were surveyed.2 Weights were applied to make the survey estimates applicable to the entire population of children in grades 6 through 12.3
The NHES:93 results suggest that unsafe conditions at school are not uncommon. About half of 6th- through 12th-grade students personally witnessed bullying, robbery, or physical assault at school, and about I out of 8 students reported being directly victimized at school.4 Threats or crime at school may motivate students to develop strategies to avoid harm. In the NHES:93, students were asked to report the types of strategies that they used to avoid trouble at school or on the way to or from school during the 1992-93 school year. Data were collected from January through April 1993. Specifically, students reported on whether they ever took a special route to get to school, avoided certain places in the school building, avoided places on the school grounds, stayed away from school-related events, stayed in a group while at school, or skipped school because they were worried someone might hurt or bother them.
One-half of 6th- through 12th-grade students indicated that they do not use any strategy to avoid trouble at school, the other half reported using a single strategy or a combination of strategies. Twenty percent of students said that they tried to stay in a group while at school, but did not report using any other strategy to avoid harm, and 5 percent resorted to a single strategy other than staying in a group (figure 1).
Source: U.S. Department of Education, National Center for Education Statistics, National Household Education Survey, 1993
Differences by school grade level. Senior high school students were less likely than students attending either elementary or middle or junior high schools to report using one or more of the strategies measured in this survey. Only 43 percent of senior high school students but 58 percent of 6th- through 12th-grade students attending elementary school and 60 percent attending middle or junior high schools said they used some strategy (table 1). It is worth noting that only 11 percent of students in grades 6 through 12 attended an elementary school. According to the definition used in this report, elementary and middle or junior high school students would, on average, be younger than high school students.5 Thus, age of student may be a confounding factor in the findings about school grade level.
Differences by school type. Resorting to a strategy to avoid harm or harassment at school is more common for students attending public schools than for those attending private schools, and there is a significant difference between students at public schools to which they were assigned and those at public schools chosen by the family.
Public schools chosen by the family, attended by 11 percent of 6th- through 12th-grade students, may be in areas that are perceived as less safe than other schools, which may account for some of the difference. The programs offered by magnet schools, for instance, may attract students and their parents despite requiring youths to travel to less familiar surroundings. This distance, in itself would possibly warrant extra caution on the part of students.
Differences by student's race/ethnicity and school racial composition. White students were less likely than black students or Hispanic students to report use of any strategy to avoid harm at school.
When the racial composition of the school is taken into account for white and black students, it was white students attending schools in which most of the other students were also white who were less likely to report the use of a strategy to avoid harm at school as compared to black students in school of any racial composition.
Differences by school safety. As would expected, any encounter with victimization school increases the likelihood that students will use some strategy to try to avoid harm. Students who know that incidents of bullying, robbery, or physical assault have taken place at their schools or students who have witnessed these events were more like to report using one or more strategies to avoid such incidents. About three-quarters of students who either worry about being victimized at school who have been victimized reported using one more strategies to avoid harm (table 1).
Whether a single strategy or part of a combination of ways to increase safety at school, staying in group was the most commonly reported, by percent of students (table 2). Twenty percent students opted to stay away from certain places the school building. Relatively few students percent) chose to take a special route to get to school or to skip school (7 percent). Choice of specific strategy varied by some school and student characteristics.
Differences by school grade level. The use specific kinds of strategies to avoid harm was related to school grade level.
Differences by school type. The reports of public school students and private school students were also distinct regarding specific avoidance strategies. For example:
In fact, higher percentages of students at both assigned and chosen public schools than at private schools reported using all types of avoidance strategies.
Differences by student's race/ethnicity and school racial composition. While the NHES:93 found that the incidence and types of victimization varied little by race/ethnicity and school racial composition, some strategies used by students to avoid trouble were different for black and white students in schools of various racial compositions. To illustrate:
Student choice of specific strategy by race/ethnicity also revealed some significant differences. For example:
Black and Hispanic students were also more likely than white students to stay away from certain places in the school, to stay away from places on the school grounds, and to stay away from school-related events.
Wary of potential danger, approximately half of 6th- through 12th-grade students employ strategies to help them avoid harm, most commonly staying in a group while at school or avoiding certain places in the school. White students attending schools in which most of the students are white were less likely to report using a strategy than were black students, regardless of the racial composition of their schools. There is a striking difference in reported use of strategies between students at private schools and students at public schools, with a lower percentage of private school students than public school students reporting the use of any strategy to avoid harm at school. Students who must think about avoiding harm at school are diverting energy that should be expended on learning. Improving students' safety at school will enable American youth to redirect their concerns to school work and student activities.
The 1993 National Household Education Survey (NHES:93) is a telephone survey conducted by Westat for the U.S. Department of Education's National Center for Education Statistics (NCES). Data collection took place from January through April of 1993. The sample is nationally representative of all civilian, noninstitutionalized persons in the 50 states and the District of Columbia. This sample was selected using random digit dialing (RDD) methods, and the data were collected using computer assisted telephone interviewing (CATI) technology.
The School Safety and Discipline (SS&D) component of the NHES:93, which is the basis of this report, included a sample of students in grades 3 through 12. Two instruments were used to collect data on the school experiences of these students. A household Screener, administered to an adult member of the household, was used to determine whether any children of the appropriate ages lived in the household, to collect information on each household member, and to identify the appropriate parent/guardian respondent. If one or two eligible children resided in the household, interviews were conducted about each child. If more than two eligible children resided in the household, two children were randomly sampled as interview subjects. For households with children who were sampled for the survey, SS&D interviews were conducted with the parent/guardian most knowledgeable about the care and education of each child. If an eligible youth resided in a household in which no adult was acting in a caretaking capacity for him or her, then that "emancipated" youth responded to the interview. A sample of youth in grades 6 through 12 was also interviewed following the completion of the parent interview about the child. This report was based on the responses of students in grades 6 through 12.
For the NHES:93 survey, Screeners were completed with 63,844 households, of which 1 2,S29 contained at least one child sampled for the SS&D component. The response rate for the Screener was 82 percent. The completion rate for the SS&D interview with parents of 6th- through 12th-grade students, or the percentage of interviews conducted with parents for sampled children in that grade range, was 90 percent, and the completion rate for the youth in grades 6 through 12 who were sampled was 83 percent. Thus, the overall response rate for the SS&D interview with parents of students in grades 6 through 12 was 74 percent (the product of the Screener response rate and the SS&D completion rate). For youth, the overall response rate was 68 percent. For the NHES:93, item nonresponse (the failure to complete some items in an otherwise completed interview) was very low. The item nonresponse rates for variables in this report are generally less than 2 percent for parents and I percent for youth. Items with missing data were imputed using a hot-deck procedure. As a result, no missing values remain.
Estimates produced using data from the NHES:93 are subject to two types of error, sampling and nonsampling errors. Nonsampling errors are errors made in the collection and processing of data. Sampling errors occur because the data are collected from a sample rather than a census of the population.
Nonsampling errors. Nonsampling error is the term used to describe variations in the estimates that may be caused by population coverage limitations and data collection, processing, and reporting procedures. The sources of nonsampling errors are typically problems like unit and item nonresponse, the differences in respondents' interpretations of the meaning of the questions, response differences related to the particular time the survey was conducted, and mistakes in data preparation.
In general, it is difficult to identify and estimate either the amount of nonsampling error or the bias caused by this error. In the NHES :93 survey, efforts were made to prevent such errors from occurring and to compensate for them where possible. For instance, during the survey design phase, focus groups and cognitive laboratory interviews were conducted for the purpose of assessing respondent knowledge of the topics, comprehension of questions and terms, and the sensitivity of items. The design phase also entailed over 500 staff hours of CATI instrument testing and a pretest in which over 275 interviews were conducted.
An important nonsampling error for a telephone survey is the failure to include persons who do not live in households with telephones. About 92 percent of all students in grades 3 through 12 live in households with telephones. Estimation procedures were used to help reduce the bias in the estimates associated with children who do not live in telephone households.
Sampling errors. The sample of telephone households selected for the NHES:93 is just one of many possible samples that could have been selected. Therefore, estimates produced from the NHES:93 sample may differ from estimates that would have been produced from other samples. This type of variability is called sampling error because it arises from using a sample of household with telephones, rather than all households with telephones.
The standard error is a measure of the variability due to sampling when estimating a statistic; standard errors for estimates presented in this report were computed using a jackknife replication method. Standard errors can be used as a measure of the precision expected from a particular sample. The probability that a complete census count would differ from the sample estimate by less than one standard error is about 6S percent. The chance that the difference would be less than 1.65 standard errors is about 90 percent; and that the difference would be less than 1.96 standard errors, about 95 percent.
Standard errors for all of the estimates are presented in the tables. These standard errors can be used to produce confidence intervals. For example, an estimated 5 percent of students reported that they took a special route to get to school. This figure has an estimated standard error of .5. Therefore, the estimated 95 percent confidence interval for this statistic is approximately 4 to 6 percent.
Statistical tests. The tests of significance used in this analysis are based on Student's t statistics. As the number of comparisons at the same significance level increases, it becomes more likely that at least one of the estimated differences will be significant merely by chance, that is, it will be erroneously identified as different from zero. Even when there is no statistical difference between the means or percentages being compared, there is a 5 percent chance of getting a significant t value of 1.96 from sampling error alone. As the number of comparisons increases, the chance of making this type of error also increases.
A Bonferroni adjustment was used to correct significance tests for multiple comparisons. This method adjusts the significance level for the total number of comparisons made with a particular classification variable. All the differences cited in this report are significant at the .05 level of significance after a Bonferroni adjustment.
The authors wish to thank the following people who reviewed this report and provided helpful critique and suggestions: Marilyn McMillen of the Elementary and Secondary Education Statistics Division of NCES; Mike Cohen of the Statistical Standards and Methodology Division of NCES; John Ralph of the Data Development Division of NCES; Oliver Moles, OERI; Bruce Taylor, Bureau of Justice Statistics; and Edward D. Jonas, Jr., Atlanta Board of Education.
Nolin, M.J., Davies, E., and Chandler, K. Student Victimization at School (forthcoming).
2 A total of 12,690 parents of students in grades 3 through 12 and 6,504 students in grades 6 through 12 were interviewed in the NHES:93.
3 The survey data were weighted to the entire U.S. population of youth in grades 6through 12, not only those youth living in households with telephones.
4 Nolin, M.J., Davies, E., and Chandler, K. Student Victimization at School (forthcoming).
5 Elementary schools were defined as having a lowest grade of 3 or less and a highest grade of 8 or less Middle or junior high school schools were defined as having a lowest and a highest grade of 4 through 9. Senior high schools were defined as having a lowest grade of 7 through 12 and a highest grade of 10 through 12. Schools that did not precisely meet these qualifications were classified as "combined."
6 For additional information on telephone coverage issues and estimation procedures to correct for cove-rage biases see J. M. Brick and J. Burke, Telephone Coverage Bias of 14- to 21 -year-olds and 3- to 5- year-olds. U.S. Department of Education, National Center for Education Statistics, report number NCES 92-101.