Final Project - INSTRUCTIONS

CRJ 507 Social Network Analysis

Introduction

The final project will use all of the information you have learned in this course to create a report on a network. For the final project, you will use data from the Phoenix Open Data Portal. Specifically, you will use co-arrest data. These data represent incidents where individuals were arrested together. For the final project, imagine that you work for a police department and your supervisor has asked you to create a report on co-offending networks. Your supervisor has provided you two networks: the phx_arrest_2024_net network of co-offending for 2024 and the phx_arrest_2023_net network of co-offending for 2023.

Data

Both networks are available in the SNACpack package we have used throughout the course. Use library( SNACpack ) to load the package, then ?phx_arrest_2024_net and ?phx_arrest_2023_net to review the documentation for each network. Be sure to review the documentation as it contains important information about the structure of the network as well as the vertex attributes.

Template and Report Format

As with the labs, There is a template for the final project. The template is set up as a report in that the code chunks include the option echo = FALSE. What this does is hides the code in the final report. When you render your report, the code will be hidden so that it reads cleanly.

IMPORTANT: Do you report entire matrices or objects. These print out very long and are cumbersome to look through.

Your Task

Part I: Two-Mode Network

What can you tell me about this network and what does it tell me about co-offending? To answer your supervisor’s question, provide an analysis of the phx_arrest_2024_net network. This analysis should include a visualization (or more) of the network as well as a description of the structural properties. In your analysis, you should identify what measures of network structure you are using and explain why you have selected the measure (or measures).

Part II: One-Mode Network

How is this network different from Part I and what does it tell me about co-offending? To answer your supervisor’s question, provide an analysis of the “person” matrix for the phx_arrest_2024_net network. Create an object of class matrix using the as.sociomatrix() function in the network package. In your analysis, you should identify what measures of network structure you are using and explain why you have selected the measure (or measures).

Part III: Comparison

How has the co-offending network changed from 2023 to 2024? To answer your supervisor’s question, provide a comparative analysis of the phx_arrest_2023_net and the phx_arrest_2024_net networks. Think about the ways we discussed for comparing networks this semester. Your analysis should compare the two-mode networks as well as the “person” matrices.

Part IV: Executive Summary

This section should provide, in your own words, a summary of Parts I-III. This section should be targeted to a reader of the report who may not be familiar with network analysis, but wants to know what is going on with co-offending in Phoenix. Here are some interpretation prompts to help you with that section (though, you can don’t have to use these):

What does this network suggest about the organization or fragmentation of co-offending in each year?
What story do these networks tell about how co-offending operates and evolves?
If you were briefing a supervisor or policy team, what are the three key takeaways from your analysis?
What are some limitations of your analysis? What data or methods would help improve your conclusions?
What surprised you the most during this project—and what might that mean?

How to Submit

Download the template for this final project prior to beginning the final project.

Knitting to HTML

When you have completed your assignment, click the “Knit” button to render your .RMD file into a .HTML report.

Special Instructions

Upload both your .RMD and .HTML files to the appropriate link for this assignment on the Canvas page for this course.

Before You Submit

Remember to ensure the following before submitting your assignment.

Name your files using this format: Final-Project-LastName.rmd and Final-Project-LastName.html
Show both the solution for your code and write out your answers in the body text

See Google’s R Style Guide for examples of common conventions.

Common Knitting Issues

.RMD files are knit into .HTML and other formats procedural, or line-by-line.

An error in code when knitting will halt the process; error messages will tell you the specific line with the error
Certain functions like install.packages() or setwd() are bound to cause errors in knitting
Altering a dataset or variable in one chunk will affect their use in all later chunks
If an object is “not found”, make sure it was created or loaded with library() in a previous chunk

If All Else Fails: If you cannot determine and fix the errors in a code chunk that’s preventing you from knitting your document, add eval = FALSE inside the brackets of {r} at the beginning of a chunk to ensure that R does not attempt to evaluate it, that is: {r eval = FALSE}. This will prevent an erroneous chunk of code from halting the knitting process.