Example: Tree of Attributes for Car Evaluation

The Car Evaluation Model has the following tree structure of attributes:

Interpretation

This structure can be interpreted as follows:

1. Decomposition: In order to evaluate a CAR, we consider its PRICE and TECHnical CHARacteristics. PRICE is further decomposed into BUYing PRICE and MAINTenance PRICE. Similarly, TECH.CHAR. are decomposed into COMFORT and SAFETY, and COMFORT is further decomposed into the number of PERSons (passengers), number of DOORS and size of the LUGGAGE boot.

2. Dependency: The attribute CAR depends on PRICE and TECH.CHAR. Similarly, COMFORT depends of #PERS, #DOORS and LUGGAGE. Etc.

3. Aggregation: The values of #PERS, #DOORS and LUGGAGE are aggregated into a value uf COMFORT. Then, in the following order, BUY.PRICE and MAINT.PRICE are aggregated into PRICE, COMFORT and SAFETY are aggregated into TECH.CHAR., and PRICE and TECH.CHAR. are aggregated into CAR.

Attribute Types

The attributes in this tree are of the following types:

• Basic attributes are: BUY.PRICE, MAINT.PRICE, #PERS, #DOORS, LUGGAGE and SAFETY

• Aggregate attributes are: CAR, PRICE, TECH.CHAR. and COMFORT.

• The root attribute is CAR.

Attribute Descriptions

In DEXi’s reports, this tree is printed together with attributes’ descriptions and appears as follows:

See also

Attribute scales in the Car Evaluation Model.