Four levels of pattern recognition 

 -  Analytica Chimica Acta, 103(4), p.429-443, 1978 .
<br/><br/> Problems of pattern recognition in chemistry and other subjects can be divided conveniently into four different types depending on the level of scope of the problem. (1)Classification into one of a number of defined classes. As an example blood samples taken from persons known to be either controls or welders are considered. The problem is whether trace element concentrations in these samples contain information on whether or not a person is a welder. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>PATTERN RECOGNITION