% 1. Title: Database for fitting contact lenses
% 
% 2. Sources:
%      (a) Cendrowska, J. "PRISM: An algorithm for inducing modular rules",
%          International Journal of Man-Machine Studies, 1987, 27, 349-370
%      (b) Donor: Benoit Julien (Julien@ce.cmu.edu)
%      (c) Date: 1 August 1990
% 
% 3. Past Usage:
%       1. See above.
%       2. Witten, I. H. & MacDonald, B. A. (1988). Using concept
%          learning for knowledge acquisition. International Journal of
%          Man-Machine Studies, 27, (pp. 349-370).
% 
%  Notes:  This database is complete (all possible combinations of
%          attribute-value pairs are represented).
% 
%          Each instance is complete and correct.
% 
%          9 rules cover the training set.
% 
% 4. Relevant Information Paragraph:
%     The examples are complete and noise free.
%     The examples highly simplified the problem. The attributes do not
%     fully describe all the factors affecting the decision as to which type,
%     if any, to fit.
% 
% 5. Number of Instances: 24
% 
% 6. Number of Attributes: 4 (all nominal)
% 
% 7. Attribute Information:
%     -- 3 Classes
%      1 : the patient should be fitted with hard contact lenses,
%      2 : the patient should be fitted with soft contact lenses,
%      3 : the patient should not be fitted with contact lenses.
% 
%     1. age of the patient: (1) young, (2) pre-presbyopic, (3) presbyopic
%     2. spectacle prescription:  (1) myope, (2) hypermetrope
%     3. astigmatic:     (1) no, (2) yes
%     4. tear production rate:  (1) reduced, (2) normal
%
% Notes: the binarized version of this data set has six "independent" variables rather than 4 (see below), and the "dependent" variable 
%		simply discriminates between lenses or no lenses.
% 
% 8. Number of Missing Attribute Values:   0
% 
% 9. Class Distribution:
%    1. hard contact lenses: 4
%    2. soft contact lenses: 5
%    3. no contact lenses: 15

@relation contact-lenses

@attribute young 			{0, 1}  \\ whether or not the patient's eyes are "young" or elastic
@attribute pre-presbyopic 	{0, 1}  \\ whether or not the patient's eyes are transitioning to "adult" stage
@attribute presbyopic 		{0, 1}  \\ whether or not the patient's eyes have reached "adult" or inelastic development stage
@attribute hypermetrope	{0, 1}  \\ whether or not the patient's spectacle prescription type is hypermetropic
@attribute astigmatism		{0, 1}  \\ whether or not the patient has an astigmatism
@attribute normal-tear-rate	{0, 1}  \\ whether or not the patient has normal tear production rate
@attribute contact-lenses	{0, 1}  \\ whether or not the patient should/could be fitted for contact lenses