Model-View-Controller Architecture Example: Real Estate Information Visualization Tool CSC 540, Fall 2002

Scenario: Nancy wants to search for houses close to UNCG under $150K, so she zooms to the area on the map within one mile from UNCG, then moves the house price slider to 150K, which filters out the houses over 150K: UNCG DRILL DOWN Max List Price ($) 80K 100K 120K 140K 160

Scenario (part 2): Nancy now wants to get details on each of the remaining houses, so she selects each one by mouse clicking on it and then presses the “drill down” button: DRILL DOWN UNCG Max List Price ($) 80K 100K 120K 140K 160

Address: 500 Spring Garden List Price: $130,000 Bedrooms: 2 Bathrooms: 1 Year Built: 1930 X DRILL DOWN UNCG Max List Price ($) 80K 100K 120K 140K 160

Scenario (part 3): After looking at the details about each of the houses under $150K within one mile of UNCG, she discovers they are too old. She decides to change her overall strategy. What if she asked for a different view of the data? UNCG GRAPH Max List Price ($) 80K 100K 120K 140K 160

Scenario (part 4): So she asks for a Cartesian graph with Miles from UNCG on the horizontal axis and list price ($K) on the vertical axis. She asks the graph to show houses under 5 miles from UNCG between $140-190K: Horizontal Axis: Miles from UNCG Maximum: 5 Minimum: 0 Vertical Axis: List Price Maximum: 190000 Minimum: 140000

A Cartesian graph with Miles from UNCG on the horizontal axis and list price ($K) on the vertical axis showing houses under 5 miles from UNCG between $140-190K: 190K 180K 170K 160K 150K 140K 0.5 1 1.5 2 2.5 3 3.5 4 Miles from UNCG

Scenario (part 5): Looking at this view of the data, she quickly realizes that houses that are very close to campus are too expensive for her, and she will have better luck by looking at houses 3-4 miles away: 190K 180K 170K 160K 150K 140K 0.5 1 1.5 2 2.5 3 3.5 4 Miles from UNCG

Scenario (part 6): So she selects the houses that are 3-4 miles away by enclosing them in a bounding box. Then she asks for a map of these houses. 190K 180K Map 170K 160K 150K 140K 0.5 1 1.5 2 2.5 3 3.5 4 Miles from UNCG

The new map shows where the 3 houses are in relation to UNCG. 2 miles:

Scenario (part 7): Now she experiments by moving filters for price and age until one house is left, her dream house! Age (Years) UNCG 4 Max List Price ($) 80K 100K 120K 140K 160

Possible MVC Architecture for Real Estate Information Visualization Tool CITY MAP VIEW (houses of interest on map) MODEL (real estate data, query results, & city street map) DRILL DOWN VIEW (details about a house) CONTROLLER (manages user interaction through widgits) GRAPH VIEW (Cartesian graphs of house attributes)