Manual selection of data attributes and composition of data domain.
Select Attributes widget is used to manually compose your data domain. User can decide which attributes will be used and how. Orange distinguishes between ordinary attributes, an (optional) class attributes and meta attributes. For instance, for building a classification model, the domain would be composed of a set of attributes and a discrete class attribute. Meta attributes are not used in modelling, but several widgets can use them for providing optional labels to instances.
Orange attributes are typed and are either discrete, continuous or a character string. The attribute type is marked with a symbol appearing before the name of the attribute (D, C, S, respectively).
We used the schema to redefine the classification problem in heart disease data set. Originally, the task was to predict if the patient has a coronary artery diameter narrowing. We change the problem to that of gender classification based on age, chest pain and cholesterol level, and informatively kept the diameter narrowing attribute as a meta attribute.