In databases, results are most commonly presented sorted by publication date or relevance. In some databases, results can also be sorted by the number of citations (impact). When sorting by relevance, the publications that best match your search terms appear at the top of the list. Keep in mind that relevance criteria vary between databases, and truncated search terms are generally not considered in relevance ranking.
In Google Scholar, where the options for precise searching are limited and result sets often contain thousands of references, sorting by relevance helps to identify the most useful results.
The most common filters applied to search results include language, publication year, and peer review status. Filtering tools should be used purposefully. Before applying any filters, make sure your search query is well-constructed, that you follow the database’s search guidelines, and that you’ve chosen appropriate search terms for your topic.
Many databases allow you to limit your search to peer-reviewed journal articles (often indicated as peer review, referee, or scholarly). Other publication type filters may include limiting results to books, conference proceedings, or review articles.
Note! Some databases offer a tempting full text filter, which limits results to documents that are immediately accessible within that specific database. However, documents excluded by this filter may still be readily available through other means — via a link, as an open access version, or as a self-archived copy.
For example, in EBSCO, you can limit your search results to peer-reviewed publications and select the desired publication types (Source type). However, it is generally recommended to avoid using the Full Text filter.
In some databases, the result set can be filtered by subject areas or categories defined by the database. Subject-specific databases may also offer more detailed filters related to, for example, age group, educational level, or research methods.
Only use subject area filters if you are certain how they work in the database you are using. Otherwise, you may unintentionally exclude relevant publications.
In Scopus, the Subject area filter can be used to narrow down the result set. In this example, the results could either be limited to publications in medical journals and books (Medicine – Limit to) or filtered out (Medicine – Exclude).
Do not confuse the Subject area classification with the Keywords list. In Scopus, keyword listings are not based on a controlled vocabulary or thesaurus. Instead, use the keyword list as a source of useful terms to expand your set of search terms.
