Then, ten queries, from various topics, and
four phrases, having different syntax but similar
meanings, were determined. After each query was
run on each search engine; and each phrase
containing a query was run on the semantic search
engine, the first twenty documents on each retrieval
output was classified as being “relevant” or “nonrelevant”.
Afterwards, precision and normalized
recall ratios were calculated at various cut-off points
to evaluate keyword-based search engines and the
semantic search engine. Overall, Yahoo showed the
best performance in terms of precision ratio, whereas
Google turned-out to be the best search engine in
terms of normalized recall ratio. However, it was
found that semantic search performance of search
engines was low for both keyword-based search
engines and the semantic search engine.