  Obtaining relevant information from a collection of informational resources
in Afaan Oromo is very important for Afaan Oromo speakers, developing a system
that help users of Afaan Oromo is mandatory. That is why this study is
envisioned to make possible retrieval of Afaan Oromo text documents by applying
techniques of modern information retrieval system. In the developed Afaan Oromo
prototype, Probabilistic approach was used as an information retrieval models
and precision and recall measurement were used as the performance measurement
or evaluation technique. Apache Solr was also used as an environmental
programming language to achieve the evaluation goal. Afaan Oromo text retrieval
is evaluated using 158 documents and 13 arbitrarily selected queries that can
determine the effectiveness of retrieval using the precision-recall. The
average result obtained by our evaluation before the addition of synonymy was
72.91% precision and 86.8% recall respectively. After the addition of synonymy,
the value was changed to 71.39% average precision and 90.5% average recall. The
F-measure for the evaluation before synonymy addition was 79.25% and after
addition changed to 79.82%. The addition of synonymy improves the system
performance by 0.57%. The study therefore, experimentally proves that the
addition of the thesaurus system can improve the system performance.
Spellchecking, pagination, hit highlighting and autosuggestion is also possible
in the developed prototype for Afaan Oromo.
