TREC evaluation measures

TREC evaluation measures:

1. AP(Average Precision) is defined as:




where :
rj is the number of retrieved relevant document
#Docj(i) is the number of retrieved document when the i-th relevant document is retrieved for the j-th query.



2. MAP(Mean Average Precision) is the average AP for all queries.


3. (R-Precision) is the precision of the first R retrieved document. Where R is the number of relevant document for each query. For a perfect system, the R-Precision is 1.0.


3. TopN precision is the precision of the first N retrieved documents.