This article was originally published to a blog which has been decommissioned.
The City of Chicago has an official open data portal providing public access to city government data. A data set with details about Crimes in the city of Chicago from 2001 to present is available through the portal.
Once the City of Chicago crime data has been built into a business intelligence solution using the Open Data Bits methodology, a user can begin exploring a data set with over 5 million unique entries using a data visualization tool. The examples below are using Power View for Excel 2013 to display City of Chicago crime data from a Power Pivot solution.
At a high level, slicers on the right hand side of the Power View report can be used to filter crime locations on the map, a vertical bar chart of crimes by hour of the day, and a horizontal bar chart of crimes by year (segmented by arrest or no arrest). There are over 5 million crimes in the data set used for this example, so the map can only show a sample of those results:
Selecting “Homicide” from the [Primary Type] slicer filters all of the web parts for the data that falls within that grouping:
Selecting only the [Description] of “First Degree Murder” filters the web parts down even further:
Selecting only the year 2014, and drilling down to the month level on the horizontal bar chart, yields a much smaller set of data:
Seelcting the slicer value of “false” for [Arrest], along with clicking on the 4 am value for the vertical bar chart “Crime Count by Hour,” yields a single geographic point for which two incidents were recorded:
With a few clicks, the data visualization tool was able to take us from a report of over 5 million unique incidents to only two.
Leave a Reply