Population-Flow Info-Vis
Aimee Rydarowski
Georgia Institute of Technology
686 Cherry Street
Atlanta, GA 30331-0165
404.668.6831
aimee@gatech.edu
ABSTRACT
In this paper, I will describe the applications of the PopulationFlow Visualizer, which is structured on census data and the
Google Map API.
Categories and Subject Descriptors
H.5.2 [Information Systems]: GUI, Interaction styles (menus,
direct manipulation) Standardization, Documentation
General Terms
Measurement
Performance
Human
Factors,
Documentation,
Economics,
Keywords
Information-Visualization, Maps, Geographic
Systems, Statistics, Population, Census
Information
1. INTRODUCTION
Population-Flow is a web-based application that uses census data
and the Google Map API to illustrate the net influx and outflux of
residents, county-to-county, across the United States. Future
functionality of this application will be designed to allow different
types of users to access and manipulate database information to fit
their specific information-visualization needs by way of tailored
queries, accessible from the main interface.
2. A FLEXIBLE TOOL
The core structure of Population-Flow is designed with many
types of users in mind. Information as general as census data can
be put to many specific uses and should not favor one user group
over another, but rather be useful to all types of users at once. As
the application functions currently, Population-Flow will place on
a map, a color-specific marker on each county in the United
States, which relates to a net gain or net loss of population
between 1990 and 2000. A second relational map can be accessed
to display information associated with a specific county in
question, illustrating the counties associated with the flow of
population to and from the selected county, as well as the net loss
or gain. The data derived from this visualization can be useful to
users ranging from real-estate agents and urban planners, to
Permission to make digital or hard copies of all or part of this work for
personal or classroom use is granted without fee provided that copies are
not made or distributed for profit or commercial advantage and that
copies bear this notice and the full citation on the first page. To copy
otherwise, or republish, to post on servers or to redistribute to lists,
requires prior specific permission and/or a fee.
politicians and policy-makers, or anyone interested in seeing how
their community is changing.
3. USER CONTROL
3.1 Tailored Queries
The effectiveness of this application is based on a user’s ability to
tailor queries to access and display only the information they are
interested in and nothing more. Users will be able to submit their
own queries with knowledge of the table structures and create
table joins by using a county’s fips 1 code to manage the joins. If
a user is unable to formulate a successful query, they may submit
a query request to the web-master and their query, along with all
non-repeating successful queries will be added to a query
databank to be accessible by all users. Text boxes and slider bars
will also be available for the user to make changes in the variables
associated with all queries in the databank. Users can search this
databank by submitting key words from the available table data,
which is in the form of a pull-down menu populated by all the
categories available in the database.
3.2 Changes over Time
Future functionality will allow users to compare population
movement over a longer span of time by comparing past census
information to the latest census data. Not only will one be able to
compare population movement, but also the changing shape of
counties themselves, using maps that are associated with a
specific census.
3.3 Visualization Strategies
Along with giving users the ability to access specific data of
interest, it would be useful to give them the flexibility to display
the data in a way that will be most useful to them. This will
include the ability to change the color, shape and size of the
markers from a list of available markers, or have the ability to use
their own picture file in place of an available marker.
3.4 Complete Census Data Visualization
Although there are a multitude of ways to illustrate a body of data,
it is important to be able to picture an entire available body of
data in a specific format. A major goal of Population-Flow will
be to eventually illustrate all available census data in the context
of a map.
4. NOTES
[1] Fips code is the reference number used by the Census to
refer to a county.