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How to Prepare an Input Data File (part 3)

attribute types

N - number of examples .............. max. 250
M - number of input attributes ....... max. 50
W - number of characters in an attribute name or value .... max. 30


There are three types of attributes recognized by this server: nominal, continuous, and discrete. During data preparation phase, the user must determine to which type each attribute belongs to. The type of the attribute determines both formal and logical properties of the attribute and the format of its attribute values in the data set. The user should therefore format her/his data for each attribute in respect to its type, according to the rules described in the next section.

Attribute types:

nominal
These are attributes which have descriptions as its values. Examples:
attribute with the name Package_size can have values
small
large

and attribute with the name Days_of_the_week can have values
Monday
Thursday
...


continuous
Attributes which have numerical value. Examples:
attribute with the name Amount_available_on_the_account can have values
23.05
-17.50
...

and attribute with name Total_population can have values
120000
50500


discrete
Attributes which have integer values 0-1000. These attributes are used as continuous ones but for attributes whose values mean also a class membership. They have properties of both nominal and continuous attributes. Examples:
attribute with the name University_year can have values
1
2
3

and attribute with the name Protection_level can have values
1
...
5



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© 2001 LIS - Rudjer Boskovic Institute
Last modified: September 22 2018 03:39:25.