Crime statistics are kept by the state of California. The state's attorney general is required by law to gather, examine, and report statistical data that offers reliable indicators of crime and the administration of justice.
California Crime Statistics
California crime statistics can be accessed at https://oag.ca.gov/crime, under the department of justice. The website includes historical and current publications on crime, homicide, and other types of crimes in California, as well as crime data from county and local law enforcement organizations.
Statistical Approaches
The State of California presents its data using a variety of statistical approaches. First, the state provides raw data from counties and local enforcement agencies. Secondly, the justice department provides main overviews of the data through measures of central tendencies, frequencies, and measures of dispersion.For instance, in presenting an overview of arrests 2015, the state uses percentages. It reports that the rate of arrest was 3,641 per 100,000 residents. In presenting the trend of arrests in the past ten years, the department uses measures of central tendencies. Through measures of central tendencies such as means, the state provides gender differences in committing crimes. The mean age of arrested individuals is also presented. For example, statistics from the site indicates that people between 18 and 40 years were more likely to be arrested compared to other age groups. Additionally, the state compares arrest rates based on race and use a combination of statistical methods to present the data.
Data Presentation
The department relies heavily on line graphs, bar charts and tables to present their data. For instance, the website provides an interactive chart of the most recent crime statistics. A bubble chart is used to present arrest rates relative to state average ethnicities. From the chart, the audience can learn, for example, the arrest rate, crime rate and the population of each county.Although the state utilizes charts and other visual tools, there is an enormous opportunity for improvement. The selected charts are complex to interpret, particularly to someone with little or no statistical knowledge. It is recommended that because the site is in the public domain, the publishers should employ simpler charts such as line graphs, bar charts, and pie charts.
The New York Police Department
The New York Police Department is one of the most famous police departments, not only in the U.S, but globally. It is a requirement for the department to maintain crime data.
New York Crime Statistics
In its website http://www.nyc.gov/html/nypd/html/crime_mapping/nyc_crime_map_introduction.shtml, the state maps crime rates and felonies in New York. In the website, users are directed to different sites that provide crime statistics, crime map and technical notes to help understand the statistics.The statistical methods and approaches used to present the data range from measures of central tendencies to measures of dispersion. For example, the different types of crimes, including murder, rape, robbery, felony assaults, and burglary are presented in terms of means. In order to depict trends in the different types of crimes, the department uses the average change in crime.
Data Presentation
NYPD performs poorly in using visual aids and tools such as charts and graphs. The only tool available on the site is a complex crime map. The map provides a comprehensive and interactive view of crime rates. It focuses on providing crime rates per 1,000 residences. For instance, based on the map, the crime rate in Brooklyn is 0.9275 crimes per 1,000 residents. Several tables are also used to show the historical perspective of the crime rate.Therefore, the core recommendation is for NYPD to simplify its crime data presentation by employing numerous visual tools. For instance, it would be prudent to present the historical rates of crime using an interactive line graph. An interactive line graph is easier to interpret and may capture more data points compared to tables. In order to identify which areas have high crime rates, the department can use bar graphs. Bar graphs, combined with interactive line graphs, can provide a more user-friendly presentation of crime statistics.
