Introduction

General Rules

Main Search Strategies

• Searching by Citation
• Searching by Title
• Searching by Author (Special Characters in Author Names)
• Searching by Keywords
• Searching by Date Ranges
• Searching by DOI

Extra Benefits of Full-Text Searching

• Finding articles from a particular institution
• Finding articles that cite a paper written by a certain author
• Finding articles using a special reagent or technique

The Order of Displayed Results

Using "Phrases"

Using "Wildcards"

Boolean Logic

Capitalization and Punctuation

Stemming

Search Term Highlighting

Search Errors

Introduction

When searching for an article, searches that are specific will run faster and will be more likely to return the actual article(s) of interest. For best results, you should enter the minimum amount of information necessary to uniquely identify the article or articles, such as volume/page number, authors, and/or specific key words. This specificity can be achieved through prior knowledge, appropriate use of phrasing and Boolean logic, and application of some specific search advice.

General Rules

There are two search boxes. The Search by Citation box always takes precedence over the Search by Authors or Keywords box, so an invalid citation in the top box will return no articles even if there is a valid citation in the bottom box. All fields in either box are connected with an AND expression, while words in a field in a specific box are connected by OR.

Main Search Strategies

Extra Benefits of Full-Text Searching

Searching the full text of an article can reveal much more information than a simple abstract search. More information than just the results and discussion is indexed; this information can be used to identify articles that are related in ways separate from the subject of the research. The following table illustrates how full-text searches can identify a valuable range of articles.

The Order of Displayed Results

Search results are listed in order of 'relevance' - in general, this means that articles which contain the greatest number of the search terms in the greatest frequency will be listed first. In practice, this means that if you enter

signal transduction

into the "Words anywhere in article" box, the search engine will find all articles which include either the term signal or the term transduction, but will list any which use both terms before any which use only one or the other, and will list articles which use the terms more frequently before those which use them less. Articles in which the word appears in the Title/Abstract are listed before articles containing the term(s) only in the text.

Using "Phrases"

Words in a field are assumed to be connected by a Boolean OR statement unless otherwise specified. One way to connect two words is by enclosing them in quotation marks. For example, the search

signal transduction

will return articles which include either the term signal or the term transduction (or both). A phrase search enclosed in quotation marks:

"signal transduction"

will only return articles where the term transduction immediately follows the term signal; articles containing only signal, only transduction, or even "transduction signal" are not returned.

Using "Wildcards"

The wildcard character (*) can be used to search the beginning fragments of words, forcing a match with any word containing a given root. Although this function is somewhat duplicated with the search engine's Stemming feature, proper use of a wildcard can return a range of potentially interesting documents. For example, a search for

child*

will return articles containing child, childcare, and children; likewise, a search for

phospha*

will return articles containing phosphatase and phosphate.

Wildcards can also be used to truncate words before non-English characters such as an umlaut (ü) or an accent (é). Since these characters cannot be searched, a word such as the author name Grundström should be searched as Grundstr*. Note that wildcards can only be used after characters; any characters following a wildcard in a single word will be discarded, and may cause an error.

Boolean Logic

Basic useful Boolean terms include AND, OR, NOT, and ( ). These terms are used to connect the words in a search. They can be used by themselves or in combination to specify your search terms. Although Boolean terms can be used in the "Author" field (with last names only), they are most commonly used in the "Word(s)" fields. Words within a field are assumed to be connected by OR unless otherwise specified. The OR connector is not often used since it is the default expression between terms. However, it can be helpful in organizing a complex query.

The AND connector limits the search results to articles that contain all of terms that are connected by AND. For example, a search for

human diseases will return all articles that contain the term human or the term diseases (and depending on the journal, this could cause an error). In practice, this will retrieve articles as diverse as human evolution and avian diseases. Inserting an AND statement like so:

human AND diseases

ensures that only articles that mention both human and diseases will be returned.

The NOT term can be used to exclude articles containing certain terms. For example, if you wanted to search for articles about the gene called sos that did not deal with Drosophila, the search would be constructed as such:

sos NOT drosophila

For more complex searches, these operators may be combined with one another, optionally using parentheses to group terms to avoid ambiguity in a complex query. For example,

("signal transduction" AND (phosphorylation OR kinase)) NOT xenopus

finds only articles which use the phrase "signal transduction" and either the word phosphorylation or the word kinase, but do not mention the word Xenopus.

NOTE that when using boolean terms, it does not matter if you select 'any' 'all' or 'phrase' from the 'words:' section. They will all produce the same result when combined with boolean operators.

Capitalization and Punctuation

Searches are case-insensitive as long as lower-case letters are used; upper-case search terms will retrieve only articles where the upper-case term is used. For example, a search for

thrombin

will return all articles containing the term, but a search for

Thrombin

will generally return articles where Thrombin is the first word in a sentence. In general, you should use lower-case in all of your searches unless you have a specific reason to do otherwise.

Punctuation is not searched and is treated as a space. The only exceptions to this are parentheses "()" and asterisks "*", and the use of a hyphen "-" in author's names. Therefore, the parentheses and the wildcard character have special meaning in the search context and cannot be searched in the text. If a search term includes punctuation (such as a dash "-" or a plus "+"), enclose the whole word in quotation marks to ensure that proper spacing is maintained in the search.

Stemming

The search mechanism uses a "stemming" mechanism to find words which are similar to the words you enter. For example, a search on

transcription

may turn up articles containing similar words such as transcript and transcribed. These additional words may not always be highlighted in the text. If you wish to disable stemming, enclose each individual term in quotation marks. If you do so, and also use Boolean connectors to combine terms, be sure that AND, OR, or NOT are not included in the quotation marks.

Search Term Highlighting

Search terms are highlighted in bold text in the title display of the search result, as well as in articles and Abstracts viewed from a search result. All words longer than four letters specified are highlighted, whether or not they are combined by quotation marks. For example, a search on

"motor cortex"

will highlight instances of the phrase "motor cortex", as well as any uses of the words motor or cortex.

Search Errors

There are two reasons that you may not get any articles back from your search: an error occurred with the search engine program itself, or there may not be any articles matching the search criteria.

If your search was executed properly but did not return any articles, the message "Your search retrieved zero articles." will be displayed at the top of the screen, along with some suggestions for narrowing your search. In this case, the search can be broadened as described above to redefine the search. Appropriate use of wildcards with search terms, or author names for which you are not sure of the exact spelling, can also help. There is also the possibility that no articles matching your interests are in the journal's collection.

When a true search error occurs, the message "There was a problem with our search system." will appear at the top of the screen. This most commonly means that too many articles were returned. This will happen if a common word (for example, and or the) is used. Single letters not included in a phrase will return similar errors. Finally, note that parentheses and quotation marks come in sets: if only one is used, an error will result. Ensure that you are not using common words or single characters; if the error cannot be resolved, send us feedback describing the problem.