To err is human, and that includes when we search databases. And while there is always a possibility of typos and errors in searches, the chance of errors increases with the complexity and length of search strategy used.

Most databases, including Pubmed, have mechanisms of alerting a searcher of certain errors found within a search by providing “warnings”, but unfortunately not all typos cause a functional error, and in those instances the database will not provide a warning and the user may end up with unintended search results.

Functional Errors in PubMed

Functional errors in PubMed trigger a warning, as they impede in the function of the database to conduct the search as written.

Quoted phrase not found in phrase index

Not all phrases (string of words you enclose in double quotes) can be found in PubMed due to how PubMed indexes phrases. 

“progenitor cell transplantation”

The easiest solution to this error is remove the double quotes, however this can lead to unintended results if you are not careful. There are several things to keep in mind if you simply remove the quotation marks. 

• If you remove double quotes from a phrase not found, but are using a specific field code, the search would be broadened by implying that there are Boolean operator AND in between each word, but the field code prevents PubMed from automatically mapping.  

“progenitor cell transplantation”[tiab] → progenitor cell transplantation[tiab]

• If you remove double quotes from a phrase not found, but are not using any field codes at the end of your phrase, the automatic translation by PubMed would become much broader than intended as it will add additional mapping to MeSH terms and word variations for each separate term.

“progenitor cell transplantation” → progenitor AND cell AND transplantation

PubMed recommends using proximity searching to fix this error. Proximity searching is a newer feature in PubMed that allows the user to control how close terms are to one another. In the example below it would only retrieve results in which all 3 terms were found within 3 words of one another.

“progenitor cell transplantation”[tiab:~3]

The last and most extreme solution to this functional error is to switch to a database that does not restrict phrase searching, such as Embase.

The asterisk in your search was ignored

If you are using an asterisk as a wildcard (truncation) in a search strategy, you must use 4 or more characters.

The easiest way to fix this error is simply lengthen the root word to at least 4 characters to truncate and include all possible endings.

The following term(s) were ignored:

This error is usually caused by a typo where something in your search is unbalanced or unpaired, including parentheses, quotation marks, and duplicate boolean operators. 

If you are unable to quickly locate where the issue is, go to Advanced Search and click on the ! under details. This will expand out your entire search strategy and highlight where the error is located.

Common Search Typos

Since these are typos, they often do not trigger a warning within PubMed so it’s important to carefully check your search strategy to make sure everything is correct.

Boolean Operators

Boolean operators (AND, OR, NOT) must be fully capitalized. If they are not capitalized or only the first letter is capitalized, the search translates it as a term and not a Boolean operator, meaning Or would find the word Or in the record but would not OR together two terms. 

If a Boolean operator is omitted PubMed will automatically insert the AND operator. Since AND and OR produce significantly different results, an unintended AND where the search needs an OR would cause a serious alteration in the results, but since it is a legitimate search technique, there would be no warning from PubMed.

Scopus has updated their website and with it has added several new tools and resources aimed to provide additional support for researchers and authors.

Researcher Discovery

Scopus introduced it’s new Researcher Discovery tool to help researchers find and connect with leading researchers in their discipline as well as find collaborators for projects, all with simple keyword searching.

How to Use Researcher Discovery

1. To get started, click on Researcher Discovery, found on the Scopus main page menu bar
2. Enter the keywords to quickly find researchers in a particular field
3. Choose the criteria you want to use to sort your search results
4. Quickly refine results based publication date, country, or even organization
5. Preview Profile includes a synopsis of the authors information (including most recent affiliation and e-mail address, years of experience, and research topics)
6. Clicking on Full Profile allows you to explore an author’s full Scopus profile including metrics

Make Connections in Scopus!

Researcher Discovery is a vital tool for early and mid-career researchers that can increase their visibility, and support collaboration, network building, and career development; or for those researchers embarking into a new or emerging field to identify, connect, and build collaboration among researchers.

For more information, please see Scopus’s Researcher Discovery FAQ page.

Author Position Metric

Scopus just announced a new metric available within their Author Profile pages. This new Author Position metric is designed to help researchers better track and understand their research performance, including providing a comprehensive overview of their performance over time that can be used for promotion, tenure, and grant applications.

What is Author Position and how does it work?

Most research includes a number of contributing authors, and using traditional author metrics all co-authors are weighed equally when accounting for citation impact. This often over-inflates the contributions of some authors and minimizes the contributions of other authors.

With the new Author Position metric, Scopus now captures the following authorship positions, including:

• First author: The first author mentioned in the publication
• Last author: The last author mentioned in the publication
• Corresponding author: An author is marked as the corresponding author in the publication (since June 2020, all new documents in Scopus can contain multiple corresponding authors, prior published and indexed documents can only have one corresponding author)
• Co-author: Co-authors are any author that is not a first, last or corresponding author
• Single author: An author is the only author of a publication

How to Find Author Position Metrics

From the Author Profile page, find the Author Position preview in the lower right column. From there, select View Author Position Details to expand details on authorship position metrics.

The Similar articles feature is one of many built-in tools that PubMed offers for finding references. This tool works by using a specific article as a starting point, and using it’s own internal algorithm identifies articles that are similar to the original article within PubMed. The similar articles tool is especially helpful if you cannot find a sufficient number of relevant references by conducting a regular search in PubMed.

Similar articles to a specific article can be located by scrolling down the record (it’s found directly underneath the abstract and conflict of interest statement), or you jump directly to the section of the page for Similar articles found in Page Navigation on the right-hand column of the record.

Under the Similar articles heading you will see several references listed and you will find the rest of references when clicking See all similar articles beneath. The number of references found this way typically is manageable, not overly large.

As was mentioned above, there is an underlying algorithm that determines what Similar Articles search finds, i.e. determines the criteria for the relevance of these references to the one you’ve used to find them.

It is possible that what the algorithm determined was important to focus on from the initial article to retrieve similar citations is not the part of reason you selected the article as relevant. You may see a mix of references that match the topic of your initial reference very closely and the ones that are less relevant but still related. The default sorting order of this search results is always Best Match, with most relevant (as determined by the search algorithm) on the top but you may find very relevant references down the list of search results as well.

Just as you would in a traditional PubMed search, within the Similar Articles portion you can adjust the results by changing the sorting order or using the filters found on the left-hand pane – with some caution. You can also click on Advanced under the search box and use the Search Builder and History and Search Details to combine your Similar articles search (expressed as Similar articles for PMID number of an original article) with other searches or build on it.

NOTE: it is most important to remember is that in most cases, for best results, Similar Articles search should be complementary to a regular PubMed search and not the main method of searching.