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Equation [2.9] uses notions of precision, overlapping and distance. The precision
score [2.10] evaluates the relevance of a document, in other words if the common
period O (Figure 2.9: overlapping part, considered to be relevant) occupies a large
percentageoftheperiodrelativetothedocument D
f
.Inasimilarway,the overlapping
score [2.10] evaluates the ratio of the period relative to query Q occupied by the
common period O. The higher this score, the more significant the corresponding
document is. Finally, the distance score [2.10] evaluates the distance of the centroids
of the period relative to query Q and that of the common period O. The closer these
centroids are to each other, the more relevant the document fragment D
f
is.
Precision(D
f
,Q)=
O
D
f
Overlapping(D
f
,Q)=
O
Q
[2.10]
Distance(D
f
,Q)=
d
D
Figure 2.9. Elements of measure of temporal similarity
2.4.6. Evaluation and Discussion
We evaluate the effectiveness of the indexing performed by the PIV process flow
ontheonehand,andthequalityoftheIRsupportedbythePIVIRSontheotherhand.
2.4.6.1. Evaluation of the PIV indexing process flow
The evaluation of the spatial indexing process flow [SAL 07c] has been
performed on a sample composed of 10 topics (travelogues), which have been
scanned and gone through optical character recognition (OCR). The PIV process
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