The average precision for the DOTGOV and disk45 collection did very marginally improve using normalised IDF Finally, it is worth mentioning some of the newly generated stopwords
found using the baseline approaches for each collection (See Table 6).
Many studies have shown that effective retrieval requires consideration of all terms occurring in documents, other than stopwords
(content-free terms such as "the" and "furthermore"); attempts to reduce the volume of index terms to a smaller number of descriptors have not been successful.
For future performance improvements, keywords and stopwords
should be determined by the environment, which will improve the speed and quality of processing by reducing overall dimensionality.
In query logs released by AItaVista , 13% of about 7M queries have an entry in Wikipedia (this was checked without removing stopwords
and with no morphological normalization, which will most likely increase the percentage further).
were removed from the collection, and the Porter stemmer [Porter 1980] was applied to the collection text before pseudowords were generated.
In addition, we use the highest-frequency words as context words, which are generally removed as stopwords
by other approaches.
Unfortunately, this query will surely return zero hits from Dialog, because it contains the stopwords
"with" and "the." Therefore, a correct translation must remove these stopwords
from the expression, which then yields
This list was further filtered to remove stopwords
. For each topic, a normalized vector of relevant documents per server was compared with a normalized vector of server scores for each distinct probe term pair.
, and possible proper nouns are discarded.
The API allows filtering of the raw text, by applying a format filter, character normalization filter, and a synonyms and stopwords
Stemming and case stripping were applied to all query terms before adding them to or looking them up from the metaindex; no stopwords
While the dictionary is only moderately large, the exact size of a concordance depends on a number of parameters, such as the omission or inclusion of the most frequent words (the so-called stopwords
) and whether stemming is first done - in our experiments, all words, as they appear in the text, are used.