LibrarySearch uses an algorithm to rank search results by their relevance to your keywords. This is combined with factors related to qualities of the information contained in your search results.
This is called “dynamic” and “static” ranking. These factors work together to generate a "score" for each result. The higher the score given to an item, the higher up the list of your results it features.
Dynamic Rank
Field weighting – when a keyword or phrase matches an item in LibrarySearch, a score is generated according to the field in which that phrase or keyword is featured:
- Title, Subtitle and Subject fields are scored the highest.
- The Author and Abstract fields are lower than these, but higher than the other metadata fields.
This search for “social media” matches the title, subject field, and the abstract of this book record. As a result, this will sit high up the list of hits.
<Term weighting – matches on rare keywords are weighted higher than matches on common terms. For example, if a search is Yoruba books, the less common term "Yoruba" has a higher influence than the common term "book".
Term frequency – the number of times a keyword or phrase is matched within a field is also considered. For example, if the search term is nanobiotechnology, an abstract that contains five occurrences would score higher than an abstract of the same length that contains the term only once.
Stemming and alternative spellings – features such as stemming and alternative spellings are applied automatically. If you entered the term ‘painting’ LibrarySearch would also search the ‘stem’ of this for words such as paint and painters. The same would apply for alternative spellings of the same word. You can search using one of these spellings and get hits for both - accessorize or accessorise; analog or analogue; theater or theatre. Exact spelling matches will be given a higher score than alternative spellings. e.g for the keyword, theatres, the results for "theatres" would get higher relevance scores than the results for "theaters" or "theatre".
Phrase searching - entering a phrase in double quotes (" ") limits results to exact phrase matches. For example, a search for "social media" (in double quotes) will return exact matches on "social media".
Phrase and proximity match boost – if double quotes are not used for a phrase, matches on the exact phrases as well as close phrase matches are both given a boost in the score. For example: If your search is American history (without double quotes), the exact phrase match "American history" scores higher than a non-exact phrase match. However, "American automobile history", and "American automobile history" will also score higher than, for example, a match on "American" and "history" appearing in different fields.
Exact title or title + subtitle match boost – the score is boosted for cases where search terms match a title or title + subtitle. For example: Graphic Design Theory -
Static Rank
This represents the default ‘value’ of a search result and does not relate to keywords. Static Rank factors include:
Content type – items are weighted according to their content types. Academic content will gain a higher score. For example, journal articles are weighted higher than magazine articles or newspaper articles. Books are weighted higher than book reviews; Journals are weighted higher than conference proceedings.
Publication date – recent items are weighted higher than older items.
LibrarySearch uses carefully designed mathematical functions specific to each content type to maximize the effectiveness of this factor. For example, the penalty for having an old publication date is higher for journal articles than for books.
Scholarly/Peer Review – articles from "scholarly" or "peer reviewed" journals are boosted.
Highlight local collections – items in UCA Library collections are boosted.
Citation counts – publications with high citation counts will be given a boost in their scores.
Scoring
Each record's Static Rank score is calculated from a combination of these factors: for example, a journal article published 5 years ago with 100 citations would probably have a higher Static Rank score than a journal article published 6 months ago with 0 citations. In this case, the benefit of the high citation counts of the first record outweighs the benefit of the recency of the second record.
The scores from Dynamic Rank and Static Rank factors are then combined to determine the relevance score of each record for the given search terms. The ranking of a search result set is determined by the final relevance scores of the records in the result set.
Other factors
Short and general topical queries (for example linguistics, global warming) tend to return more books, eBooks, references and journals among the top results, and long and specific topical queries (for example linguistics universal grammar, global warming Kyoto protocol) tend to return more journal articles among the top results.
Ways you can influence search results
Filters
One of the easiest ways to influence and take control of search results is to use the filters provided on the left-hand side of the screen. You can limit content types such as books and journal articles or full text online information or choose different date ranges, library locations and subject areas.
Boolean operators
Can also be used in LibrarySearch to influence the rank of hits. AND, OR, NOT operators are supported. The operators must be written in capitals to ensure that they are interpreted as Boolean or used within the Advanced Search. Boolean searches will also be subject to the relevance ranking algorithm outlined above.
- The AND operator – When there is no explicit Boolean operator between two terms, the AND operator is assumed anyway. For example, if you search for sustainable fashion, you will get the same result set as when you search for sustainable AND fashion. However, the ranking of the results may be different since the first search (sustainable fashion) applies higher relevance scores to phrase matches and proximity matches on "sustainable fashion".
- The NOT operator – The NOT operator can be used to exclude a keyword from the search results. Examples: “contemporary art” NOT photography.
- Advanced Search - Using the Advanced Search also allows you to have more control over your search results. Combine Boolean searches with other factors, such as selected content type and the ability to specify fields, such as title or subject.
