Monthly Neighborhood Offense Statistics Report Walkthrough
1. Report Overview
The Monthly Neighborhood Offense Statistics is an interactive data visualization of the offenses that are reported to the Portland Police Bureau. This tool is built to provide custom analyses of offense data to interested members of the community, especially as it relates to the Portland neighborhoods. For a more detailed map of the neighborhood boundaries used by the Police Bureau, click here.
Offenses are reported using the National Incident-Based Reporting System (NIBRS) maintained by the FBI. NIBRS provides a comprehensive view of the occurrence of crime by reporting all unique offenses within an incident rather than just the most serious offense. Prior to April 2015, the PPB reported statistics using the Uniform Crime Reporting (UCR) Program’s Summary Reporting System (SRS). The different reporting systems and processes prevent any crime statistics prior to April 2015 from being compared to current NIBRS data. For more information on NIBRS, click here.
2. Technical Specifications
The report has been customized to work on personal computers, smart phones and tablets. For the best experience, it is recommended you use a desktop or laptop computer.
3. Visualization Walkthrough
The Monthly Neighborhood Offense Statistics is an interactive data visualization. This interactivity allows users to filter the information based on the questions they are hoping to answer with this dataset. An overview of the pre-built filters is included below.
a. Date Filter
The Date Filter is the primary selection tool for the date range. The dropdown filter defaults to the 13 most recent months that data is available. To change the months in view, hit the down arrow to the right of "(Multiple values)" and select the check boxes next to the corresponding months and years you would like to view. There is no limit to the number of months; however, the Offense Count by Month chart gets crowded past 14 months.
b. Offense Count by Category
The table on the left-hand side of the report, Offense Count by Category, provides a detailed listing of the reported frequency of offenses during the selected time period. For more information on the offense, including the definition, hover the mouse over the value (number).
The table does more than just provide information as it also doubles as a filter. Clicking on the name of a particular offense category, such as Burglary, automatically updates the Frequency Map and Offense Count by Month to show the distribution and frequency of those crimes. Multiple offenses can be selected by dragging the mouse when clicking or holding down the CTRL button on the keyboard when clicking the offenses.
TIP: To filter for all offenses in the “Crime Against” category (i.e., Person, Property, or Society) click that label instead of individual offenses.
c. Frequency Map
The Frequency Map is an outline of all Portland neighborhoods using the Portland Police Bureau boundaries. The map dynamically updates based on selected filters. Darker colors signal a higher number of reported offenses. The minimum and maximum values on the color scale adjust based on the other filters. Hover the mouse over a shape to get basic information about that neighborhood, including its name, coalition, and the count for all selected offenses.
Like the Offense Count by Category view, the map can also be used to filter results in the different tables and charts. To filter statistics by neighborhood, select the neighborhood on the map. Multiple neighborhoods can be selected by dragging the mouse when clicking or holding down the CTRL button on the keyboard when clicking the neighborhoods.
A link is provided to instructions on finding the neighborhood of a specific location on PortlandMaps.com. Use the text box just above the map to highlight the neighborhood’s location on the map.
TIP: Just using the “highlight” function does not filter by that neighborhood. After a neighborhood is highlighted, make sure to click on that neighborhood shape to filter the results.
d. Total Offense Count by Month
The final view on the main report is the Offense County by Month bar chart. This chart highlights the total offense count (or, if filtered, the total count of all selected offenses) for all months included in the overall date filter. Like the Frequency Map and Offense Count by Category table, the bar charts can also be used to filter results; select one (or more) months to view the offense and regional breakdown for that month.
TIP: Select more than one month by dragging the mouse when clicking or holding down the CTRL button on the keyboard when clicking the month.
The toolbar, located at the bottom of the visualization, contains several buttons that assist in the analysis of the data.
The “Undo” and “Redo” buttons become active when the above filters are applied to the report. They operate just like the Undo and Redo buttons in other programs such as Microsoft Word.
The “Reset” button reverts all filters back to their original setting when you first visited the page. This is a great way to start with a “clean slate” after clicking several filters.
Tableau is the name of the software used to create this report visualization.
The “Download” button allows users to save a static version of the visualization. This option is great for printing out copies of the map to share at meetings or to include in a presentation.
“Get the App” takes you to a download page to acquire a Free Trial of Tableau Desktop. This is not necessary, or recommended, to fully analyze and view the report.
“Tableau Workbook” allows you to download a file that works with the full version of Tableau Desktop, mentioned above. This is not necessary or recommended.
“PDF” allows users to export the report, with all of the filters you set, as a PDF. The options dialogue allows custom scaling and paper size options. When choosing to export as PDF, make sure to keep the layout as portrait and content as “this dashboard.”
The "Crosstab" and "Data" options are unavailable for use on the workbook's main page. To download a copy of the data for your custom analysis, refer to the next section of this walkthrough.
“Image” creates a .png file of the report with all of the selected filters.
f. Download Data
The Portland Police Bureau is a proud member of the Police Data Initiative. Open Data provides an opportunity to improve the relationship between the community and the PPB by increasing transparency, building community trust, and strengthening accountability.
The Download Data tab of this report was custom-built to meet the Bureau’s Open Data goals. To download a copy of the data for custom analyses and presentation, follow these steps:
- Click on the Download Data tab at the top of the report.
- Use the optional filters to splice and shrink the dataset based on desired parameters.
- Click on the “Download” button on the toolbar in the lower-right corner of the report.
- Click on “Data.”
- A new window will pop-up that shows only the first 200 rows of data. Click on the blue link that says “Download all rows as a text file.
- Once downloaded, the file can be imported to Microsoft Excel or other data analysis programs.
Location data is only provided to the block level to preserve victim anonymity. Cases deemed sensitive due to the nature of the crime, victim, victim/offender relationship, or investigation status may contain data that cannot be shared openly at this time. Case numbers and specific location information for sensitive cases are not included in the open data. These Case Numbers are signified with an “X” in their title.
TIP: If address information is not required for the desired analysis, click “Crosstab” instead of “Data” under the download tab. This removes a couple of steps, but still preserves all selected filters.