El Grito de Sunset Park Use Case
Step 2: IDENTIFYING ATTRIBUTES
Now that you have a tentative list of entities, the next step is to decide what attributes, or properties, you want to track about each of those entities. You can think of attributes as the “fields” in a database, or a “column” in a spreadsheet. For example, for the entity Officer, you might have “First Name,” “Last Name,” and “Tax ID” as attributes.
Some things to consider when deciding on attributes:
- Do you want to make your attributes align or match up with someone else’s database, so you can share data? They don’t have to be exactly the same, as long as they can map one to another.
- How granular do you want to make the attributes? Granularity refers to the degree to which your data is broken up into the smallest possible pieces. For example, having separate fields for “Street Number,” “Street Name,” “City,” and “Zipcode” is more granular than having one single field for “Address.” Generally, the more granular the data, the easier the data are to sort and analyze. Granular data are also more flexible — it’s easier to combine granular data together than to break “un-granular” data apart. However, the more granular your data, the more time and care you need to put into creating and entering them.
- What information do you actually have? You can make up all kinds of attributes, but it’s not going to be very useful if you don’t actually have the data to populate those attributes in the database.
For the most part, if you have a good set of entities, identifying attributes for your data model is fairly straightforward.
El Grito Example
To determine the attributes in the El Grito model, we looked at the types of information that the team was including in the spreadsheet and the officer dossier. We also looked at what attributes other groups were using in their metadata models.
Here is a preliminary list of attributes for each entity. Any attributes that are also entities are noted in parentheses (more on this in the next section on Relationships):
|Entities||Preliminary List of Attributes|
|Officer Shield History||(Officer)|
|Shield Start Date|
|Shield End Date|
|Officer Rank History||(Officer)|
|Rank Start Date|
|Rank End Date|
|Officer Salary History||(Officer)|
|Salary Start Date|
|Salary End Date|
|Officers at Police Precincts History||(Officer)|
|Police Precincts||Precinct Number|
|Officers at Incidents||(Officer)|
|Squad Car Number|
|Squad Car Plates|
|(Complaint or Lawsuit)|
|Complaints or Lawsuits Related to Incident||(Incident)|
|Court or Board|
|Cause of Action|
|Time of Day|
|Type of Incident|
|Incidents on Video||(Incident)|
|Filepath of Archived Copy|
|File Modification Date|
|People at Incidents||(Person)|
|Role in Incident|
|Information Person Provided|
|Arrests or Cases Against Person|
|Outcome of Cases Against Person|