Headline: “Police Statistics Show Fighting and Illegal Drug Reports Declining at Hinsdale South” —Patch, March 18, 2011
Headline: “Police figures indicate steady increase in fighting at Hinsdale Central and Hinsdale South” —Suburban Life, March 24, 2011
Headline: “Statistics show drop in violence at both Hinsdale high schools” —The Doings, March 27, 2011
What’s behind these apparently contradictory headlines?
Comparing data in the articles
The Patch article on March 18 looked at police reports of fighting at Hinsdale South for 2009, 2010, and 2011 to date. According to the police statistics, reports of fights at the school declined from 23 in 2009 to 11 in 2010. As of March 15, there had been three reports of fights at the school in 2011.
The case that fighting was on the decline at the school was bolstered by data presented at the District 86 School Board meeting on March 21. According to Hinsdale South Principal Brian Waterman, there were 75 suspensions for fighting at the school in the 2006-07 school year. There were 63 the following school year and 32 in 2008-09. The 2008-09 figure represents the lowest number of suspensions in the past decade.
In 2009-10, there were 47 suspensions for fighting, but just 16 to date for the 2010-11 school year. With the school year well over half complete, Hinsdale South is on a pace to record the fewest number of suspensions for fighting in the past 10 years.
The Suburban Life article on March 25 reported that police reports of fighting at Hinsdale South rose from six in the 2007-08 school year to 16 the following year and 21 in 2009-10.
The Suburban Life article examined police statistics broken down by school year. Thus, the last complete data set used ended in June 2010. The Patch article used calendar years to gain a more recent complete data set, ending on Dec. 31, 2010. Comparing these data sets suggests that fighting problems at Hinsdale South may have been on the rise through Dec. 31, 2009, but has been on the decline since then.
The Doings article on March 27 used the data presented by Waterman at the March 21 school board meeting and corresponding data requested from Hinsdale Central High School. It did not examine police statistics.
Both the police statistics and school data show Hinsdale Central with fewer reports of fighting over the past two years, so for simplicity’s sake, the rest of this article will focus solely on Hinsdale South and how it compares to similar schools.
How prevalent is fighting in high schools?
Patch.com contacted police departments in several area communities and asked them to provide data on the number of police reports of fighting they investigated for the high schools in their jurisdiction in 2009 and 2010. Data was provided for four neighboring high schools. Police agreed to provide the data on the surrounding schools on the condition that the schools would not be mentioned by name.
According to Darien police statistics, there were 23 reports of fighting at Hinsdale South in 2009. This was more than any of the other police departments reported for the same year for their high schools. However, the 10 reports of fighting at Hinsdale South for 2010 would have placed the school in the middle of the pack for that year.
The lowest number of fight reports for a neighboring school in one of these years was four and the highest was 20.
The Centers for Disease Control and Prevention (CDC), based in Atlanta, conduct an annual Youth Risk Behavior Surveillance (YRBS) study. The most recent data available is for 2009, released in June of last year.
The 2009 survey found that, nationally, 11.1 percent of high school students had been in a fight on school property at least once in the previous 12 months. Based on Hinsdale South’s 2009 enrollment, this percentage would equal 202 students. The number of discipline referrals for fighting at the school does not come close to equaling this figure for either the 2008-09 school year (32) or the 2009-10 school year (47).
In Illinois, 11.5 percent of high school students surveyed in 2009 reported they had been in a fight on school property in the previous 12 months, slightly higher than the national average. The data has a confidence interval of 9.9 percent to 13.3 percent. For Hinsdale South to equal even the low end of this range would have required 181 students to have been involved in fights in the prior 12 months.
The Illinois figures, of course, include Chicago. The 2009 CDC data for Chicago, specifically, shows 20.6 percent of students attending high school in the city had been in a fight on school grounds in the previous 12 months.
The CDC website does not provide a data set for Illinois which excludes Chicago. However, since Chicago represents approximately 20 percent of the state population, it’s reasonable to assume that about one-fifth of the sample was from Chicago. If this were the case, the percentage of Illinois students outside of Chicago who had been in a fight in the previous 12 months would be about 7.5 percent. For Hinsdale South to match this even lower percentage, 137 students would have needed to report they had been in a fight in the previous 12 months.
How often do fights occur?
The debate among school board candidates over fighting began with comments made by a school board member whose seat is not up for election this year. At the March 7 school board meeting, Dianne Barrett said fighting was occurring at Hinsdale South “on an almost daily or weekly basis.”
At a candidates forum three days later, Claudia Manley and Bruce Davidson both insisted that fighting at the school was a problem. Manley said incidents of fighting were “frequent” and “repeated.”
“It is not small,” she said. “It is not insignificant.”
“There is a problem there,” Davidson said. “It needs to be addressed.”
To make suspensions for fighting equal a fight for every day school is in session would require a figure of about 360. School is in session about 39 weeks a year, so about 78 suspensions would be needed to equal a fight a week. The highest number of suspensions for fighting in the past decade was 81, recorded during the 2003-04 school year. As noted previously, the past two school years combined totaled 79 suspensions.
The available data suggests that the problem of fighting at Hinsdale South is not worse than one would expect for an Illinois high school outside the city of Chicago and that the problem is not growing worse. The same can be said for Hinsdale Central, which the most recent data suggests has less of a problem with fighting than similar schools in the area.
Note: Dennis Jacobs is no stranger to data analysis, having previously worked as an analyst for marketing research firms in Iowa and Missouri. His job included making recommendations to clients that included Fortune 500 companies based on his analysis of data using sophisticated statistical software. He also worked with a mathematics professor from Stanford University to develop survey questions designed to produce the most valuable statistical information possible.