Just a small question please

[Tarik Taleb]

Hi, we are two students in master informatics. We have our master to prepare, 
so we talk in about Jena (especially LARQ) and others features in Lucene 
assoociated with based-SPARQL interrogation. We have an elemetary question 
please, we read in 
http://incubator.apache.org/jena/documentation/larq/index.html that there is 
three patterns used in LARQ, the question is simple "HOW do we choose between 
them in a request?" Thank's.