Search tips

Information retrieval can take time. On this page, you will find basic guidance on how to search effectively.

Prepare your search

Before you start searching for information, you need to consider the purpose of your search. Do you want to get an overview of a topic or explore a specific question in depth? The purpose determines how you should search.

If you are conducting an exploratory search and do not need to report how you searched, you can work more freely. If the search needs to be reproducible, it must be systematic. Start by considering the following:

• Why are you searching for information? Do you need an overview or an in-depth study?
• What type of material do you need, for example books, scholarly articles, legislation or statistics?
• How much material do you need?
• How current does the material need to be?
• Does the material need to be scholarly?

Systematic search

A systematic search is carried out in a planned and structured way according to a defined method. The aim is for the search to be transparent, meaning it should be clear how it was conducted and which sources were used.

The search must also be reproducible. This means that another person should be able to repeat the search and obtain similar results. It should also be comprehensive, meaning that it includes all relevant articles that can answer the research question.

Exploratory search

An exploratory search does not need to be documented or reported. You can use it at the beginning of your work to:

• Identify a research problem.
• Learn more about the subject area.
• Determine whether there is sufficient research in the field.
• Narrow or refine your search question so it is neither too broad nor too narrow.

Documenting the search

When conducting a systematic search, you need to document all parts of the process, since the search must be transparent and reproducible. Many databases have a feature called Search History, where you can find and save your previous searches and filters.

In addition to the search results, you should document:

• When you conducted the search.
• Which databases and search tools you used.
• Which search terms and search techniques you used.
• Which filters you applied, for example peer reviewed, language or publication year.
• The number of results in each database.
• How you selected the articles.

Find search terms

Finding good search terms is often challenging, but it is an important part of the search process. There are many tools that can help, such as encyclopedias and dictionaries. You can also use key articles and subject term lists.

Start with your research question and identify the words that describe the most important concepts. These words form the basis of your search. Then consider whether there are synonyms, broader terms or more specific terms you can use. Scholarly material may use different words for the same concept. By varying your search terms, you increase your chances of finding relevant results.

Scholarly texts are often written in English. You therefore need to translate your search terms and use the English terms in your search.

To find good search terms, you need to learn more about your topic. Use course literature, lectures, websites and encyclopedias to understand which concepts are central. You can also use AI search tools such as Microsoft Copilot or ChatGPT to get suggestions for search terms and synonyms. Use them as support, but always check that the suggestions fit your research question.

• Dictionaries
  Use dictionaries to identify terms that you can apply in your database searches.
  
• Keywords for experiences, emotions, interactions and attitudes
  On the Karolinska Institutet University Library website, you can find a compilation of useful terms related to experiences and treatment. Available in Swedish.
• Examples of AI tools that serve different purposes
  Tips on AI search tools that can help you find keywords and synonyms. From the Karolinska Institutet University Library.

Key articles

If you have found a scholarly article that is relevant to your work, you can use it to find more articles on the same topic. This is called using a key article or a gold standard article.

You can find new search terms in the article’s title, abstract and in the author’s keywords. In some databases, controlled subject terms are also linked to the article. Use these terms in your continued search to find similar material.

Controlled subject headings

Some databases include subject heading lists with controlled vocabulary. This means the database has defined which term should be used for a specific concept. These terms describe what an article is mainly about.

The subject headings are organised in a hierarchy. Broader terms are placed higher up and narrower terms further down. They are used to describe and structure scholarly articles and other materials. The headings may be added manually or automatically. When you search using controlled subject headings, you find material that has been indexed with those terms.

Subject heading lists may have different names and contain different terms depending on the database. They may be called MeSH, thesaurus, subject headings, or index.

MeSH

MeSH stands for Medical Subject Headings. It is a subject heading list developed by the National Library of Medicine in the United States. It is mainly used in PubMed and the Cochrane Library.

What is Swedish MeSH?

Swedish MeSH is a translation of MeSH developed by the Karolinska Institutet University Library. Not all Swedish terms have a corresponding term in the American version, which means some translations may be missing. Swedish MeSH is not a regular dictionary. It shows which terms to use when searching in different databases.

• Swedish MeSH
  In Swedish MeSH, you can find controlled subject headings in both Swedish and English.
  

Example from Swedish MeSH:

If you want to find a subject heading that describes critical life events that change a person’s life, you can use one of these terms:

• Livskriser
• Livserfarenhet
• Life experiences
• Life experience
• Event, life change
• Events, life change

In Swedish MeSH, the subject heading Life Change Events is identified as the term to use. Under synonyms, you can find that this term brings together all the concepts listed above.

MeSH in other databases

MeSH is mainly used in PubMed. You can also use MeSH terms as a starting point when searching in other databases. The same or similar subject headings are often used, even if databases have different subject heading lists.

Keep in mind that search results may be affected if the terms do not correspond to the database’s own subject headings. In other databases, the subject heading list is included in the database itself, but without a Swedish translation.

Search example:

If you search using the combination child AND parents AND disabilities, you will get results, but it is unclear whether the children or the parents have disabilities.

If you instead search in Swedish MeSH for the concept disabled parents, you will find the term Child of impaired parents.

In the CINAHL subject heading list, the term Children of impaired parents is used to describe the same concept.

Where to search

Where you search depends on the type of material you need and the purpose of your search. For example, you can use the Library Search Tool or subject-specific databases.

Start by defining what type of material you need. Do you need printed books, e-books or scholarly articles? Should your search be systematic or exploratory?

Search systems differ in content, subject coverage and transparency. Transparency refers to how clearly it is explained how the search works, which sources are included and how the results are selected.

The Library Search Tool

The Library Search Tool is a good starting point. It allows you to find books, e-books and articles in one place. When you use the search tool, you search multiple databases and indexes at the same time. This often results in many hits. To get more relevant results, you need to refine your search using filters.

Printed books and e-books

Use the Library Search Tool to find books. Start by searching and then limit your results by selecting the source type (books or e-books). If you want to borrow a book from another library, you can request it through interlibrary loan. Please note that e-books cannot be borrowed via interlibrary loan.

• The Library Search Tool
  Search for books, e-books and articles using the Medical E-Library's Search Tool.
• Borrow books and e-books
  Information on how to search for and borrow books and e-books, as well as access, interlibrary loans, and loan conditions.
  

Articles

You can search for articles in the Library Search Tool by entering keywords, a title, an author or an ISSN. When you use the search tool, you search multiple databases and indexes at the same time. This often results in many hits.

To reduce the number of results, use filters such as Peer reviewed, language or the source type Academic journals. If you still get too many results, it may be better to search in a subject-specific database.

• The Library Search Tool
  Search for books, e-books and articles.

Subject-specific databases

The Medical e-Library provides access to many different databases. Some databases contain full-text material. Others include only references to sources. They may also contain information such as statistics, standards, and patents.

The database list includes both openly available databases and subscription databases. Databases that require a subscription are marked with (RN). To use them, you need to sign in with your regional user account.

The advantage of searching in a subject-specific database instead of the Library Search Tool is that you can make more and more specific refinements. For example, you can refine by age group, geographical area, or evidence-based material. In many cases, you can also use controlled subject headings in your search.

Keep in mind that databases work in different ways. For this reason, review the database help section for more information about how to search in that database.

• Databases
  The Medical e-Library’s selection of databases.
  

Libris

You can search for printed books, e-books and other materials in Libris, Sweden’s national library system. Libris includes materials from Swedish university and research libraries, as well as many public libraries.

Search by title, author, ISBN, or keywords. When you receive your results, you can refine them using filters. Select Book to display both printed books and e-books. Select Electronic resource to display only e-books.

• Libris
  Search Sweden’s national library system.

Google

If you search using Google, you may miss a large amount of scholarly material. For this reason, it is often better to use the university library’s search systems and databases.

You can also use Google Scholar to find scholarly material. However, not all material there is scholarly, and it is unclear how the selection is made. It is therefore important to evaluate sources critically. The content in Google Scholar is not stable. This means that articles you have found previously may be removed the next time you search.

• Google Scholar
  Google’s search service for scholarly publications.

AI search tools

There are several types of AI tools that can be used for information searching. They work in different ways and are not suitable in all situations. When using these tools, it is important to understand how they work so that you can use them safely and responsibly.

• Searching for information with AI
  Information about generative AI and different AI search tools.

How to search

Once you have identified the purpose of your search and where to search, the next step is to consider how to search. Scholarly databases, for example, do not work in the same way as generative AI tools. It is therefore important to understand how the systems are structured so that you can decide which system best suits your purpose.

You can search in different ways depending on what you are looking for. If the search needs to be systematic, you must follow a defined method that is planned and documented. This allows others to repeat the search and obtain the same results.

If the search is not systematic, you can use a more exploratory approach to find information quickly. This type of search is flexible and does not follow a clear plan, which means others cannot repeat it.

When you search in a database or in the Library Search Tool, you can choose between a systematic search and a more exploratory search. You can also refine your search using different search techniques and filters.

• Library databases or AI search tools?
  The difference between lexical and semantic search.
• AI functions in databases
  Using AI functions such as natural language in databases.

Common search techniques in databases

When you use a traditional database, without using the database’s AI functions, you need to apply search techniques. These determine how the database interprets your search query. Not all search techniques work in every database. For this reason, review the help section in the database you are using to check what applies.

Phrase searching

If the words in your search need to appear in a specific order, you can place them within quotation marks, for example “Second World War”. The database will then search for the words as a single phrase in the exact order you entered. If you do not use quotation marks, the database searches for each word separately. This usually gives more results, but many of them may be less relevant.

Truncation

A word can have different endings. To include all variations in your search, you can add an asterisk after the word stem. This is called truncation.

Example: school* retrieves words that begin with school, such as school, schools and schooling.

If you do not use truncation, you will only retrieve results with the exact word form. For example, searching for school will not retrieve results containing schools or schooling.

Boolean searching

To combine multiple search terms, you can use the Boolean operators AND, OR and NOT.

• AND is used when all search terms must appear in the same article. It reduces the number of results. For example, television AND movies retrieves documents where both words appear.
• OR is used when at least one of the search terms must appear. It increases the number of results. OR is useful when searching for synonyms or spelling variants. A search for television OR movies retrieves documents containing television, movies or both.
• NOT is used to exclude a term. It reduces the number of results. A search for television NOT movies retrieves documents that contain television but not movies. Use NOT carefully, as you may exclude relevant results where both terms appear.

When combining synonyms with OR, use parentheses to show how the search should be interpreted.

Example: (children OR kids) AND television. The results will contain children or kids, together with television.

Controlled subject headings

Some databases provide subject heading lists with controlled vocabulary that you can use in your search. A controlled vocabulary consists of standardised terms used to describe specific concepts. This means that the same term is used consistently for the same content.

To search using controlled subject headings, you first need to find the correct term in the database’s subject heading list and then select it. If you do not, your search will be based on free text instead.

Use the database’s help section for more information on how subject headings work. Also note that terms may differ between databases.

Field searching

Field searching is an advanced search method used to narrow down results. In a database, each publication contains specific fields such as author, title, publication year and keywords. You can use these fields to control where the search is performed, for example in the author, title or abstract field.

Citation chaining

By reviewing reference lists in publications, you can identify new sources for your work. This is called manual searching or citation chaining. In citation databases such as Scopus and Web of Science, you can also see which publications have cited a particular source.

Refine your search with filters

In most traditional databases, you can refine your search by applying filters to the results list, for example by publication date, language, or source type. This helps reduce the number of results and makes it easier to identify the most relevant material. You can also apply the filter Peer reviewed or Peer reviewed journals to limit results to peer-reviewed material. Always verify that the material has actually been peer reviewed.

Many databases also provide filters for specific study designs, such as RCT studies. You can also create your own search block or use predefined search strings.

• Search filter: RCT
  Search filters from SBU, the Swedish Agency for Health Technology Assessment and Assessment of Social Services. Available in Swedish.
  
• The ISSG Search Filter Resource
  A resource that provides a range of search filters.
  
• McMaster HKR
  Search filters developed by McMaster University.

Choosing sources

A source is the material from which you obtain information. Which sources are appropriate depends on the purpose of your work and how you intend to use them.

Sources vary in their level of scientific basis and how they are used. At the beginning of a project, it is common to use several types of sources, such as books, review articles, dissertations, brochures and popular science articles. These can provide an introduction to the topic.

Sources are often divided into three categories:

• Primary
  A primary source is the original source in which information or research findings are published for the first time. It contains original data.
• Secondary
  A secondary source presents or interprets the content of a primary source. If you use a secondary source, it is important to locate and review the primary source as well.
• Tertiary
  A tertiary source summarises or compiles information from secondary sources. It is useful for gaining an overview of a subject.

Scholarly publishing and peer review

Researchers usually publish their results as articles in scholarly journals. These articles present primary research, meaning new research findings. They are therefore considered primary sources.

Research can be conducted in different ways and vary in scope. Common types of studies include systematic reviews, randomized controlled trials, non-randomized studies, cohort studies, and case studies. The reliability of a study depends on how it is designed, conducted, and analysed.

To ensure quality, articles are evaluated through a process called peer review. This means that other researchers review the article before it is published. An article that has undergone peer review has been scientifically reviewed. In some databases, you can limit your results to peer-reviewed material. In other databases, all content has already been quality reviewed. In those cases, refine the results to scholarly articles if you want to identify primary sources. You should always assess the relevance and credibility of a source yourself.

• Systematic reviews
  Here you can find more information about systematic reviews and how to evaluate the reliability of articles.
  

Different types of publications

Research can be published in formats other than scholarly journal articles. Some publication types undergo peer review, while others do not. Here are a few examples:

• Conference proceedings
  When researchers participate in conferences to share ideas and results, their contributions are often published in scholarly journals or in conference proceedings. In some cases, these are peer reviewed.
• Research reports
  Researchers may publish their findings in reports issued by departments, research institutes, organisations or government agencies. The purpose is to present ongoing or completed research. These reports are usually not peer reviewed and are often published freely online.
• Licentiate and doctoral theses
  After completing doctoral studies, researchers present their work in a thesis. A thesis is a scholarly publication in which the research is presented for the first time. It is academically reviewed and usually published openly online.
• Books and book chapters
  In many disciplines, research is published in book form. Books may be peer reviewed in the same way as scholarly articles. In other cases, they are reviewed by editors.

Grey literature

Grey literature refers to material that is not published through traditional publishers or scholarly journals. It is often produced by universities, government agencies, organisations, or companies. Examples of grey literature include dissertations, conference papers, research reports, government reports, policies, clinical guidelines, working papers, and information about ongoing research.

Grey literature is usually not reviewed through the traditional peer review process. This means that the quality can vary and that the material may sometimes contain weaknesses or incorrect conclusions. At the same time, some reports may have been reviewed internally or by experts, even if they have not undergone traditional peer review.

Why search for grey literature?

One reason to search for grey literature is to identify ongoing or unpublished studies. This can be important when assessing the risk of publication bias.

Studies that show statistically significant results are more likely to be published than studies that show no effect or negative results. By searching for grey literature, you may find material that has not been published in scholarly journals. This can help reduce bias in the overall evidence base.

Another reason is that you may need to complement published research with other types of material. This can help place the research question in a broader context.

Some topics are underrepresented in academic research. This also applies to emerging research areas where only a few studies have been published. In such cases, grey literature can be an important complement.

Searching for grey literature

Grey literature may be available in subscription databases. For example, some conference papers are indexed in Web of Science, and dissertations are often published in university repositories. You can also find grey literature through search engines or on the websites of organisations. In addition, there are specific databases that collect this type of material.

When searching for grey literature, search blocks used in database searches often do not work well. Instead, you usually need a simpler search strategy with one or a few search terms.

Searching for grey literature can take time and requires good subject knowledge. It is also more difficult to work systematically compared with database searching. Try to maintain a structured approach.

For example, you can:

• Have a clear purpose for the search.
• Define clear inclusion and exclusion criteria.
• Follow a planned search process.
• Define quality criteria for the material that may be included.
• Search similar sources in the same way.
• Create a document for documentation before you start and document the process as you go.

• Where to search for grey literature
  The Karolinska Institutet University Library provides recommendations for search services that can help you find grey literature.

Source criticism

Source criticism means examining and evaluating the sources you use to assess their reliability. A critical approach is an essential part of scholarly work. Always review and assess the sources you plan to use, since their reliability may vary. How you evaluate a source depends on the type of source and how you intend to use it.

Start by identifying the type of source. Is it a review article, a dissertation, or a scholarly article? Is the source primary, secondary, or tertiary?

When assessing a source, consider the following:

• Author
  Who is the author or publisher? What expertise and authority does the author or organisation have?
• Purpose
  What is the purpose of the material? Is it intended to inform, persuade, encourage debate, or something else?
• Audience
  Who is the material intended for?
• Currency
  When was the material published? Has it been updated?
• Credibility
  Is the content objective or biased? Does it cover the topic adequately? Is important information missing? Are facts supported by references? Who cites the material? Is the structure clear and the language appropriate for its purpose?
• Authenticity
  Is the author the person stated? Is the material genuine and unchanged?

Assess whether the material is scholarly

Although subscription databases often contain quality-reviewed articles, no source is completely reliable. Be especially careful when using material from open sources such as Google Scholar, open access journals, or AI search tools for scholarly material.

It can sometimes be difficult to determine whether an article is scholarly, but several characteristics can help you make this assessment.

Predatory journals

Predatory journals are a growing problem. As open access publishing has increased, so has the number of these journals. A predatory journal publishes articles without following accepted scholarly standards. Some articles may contain unreliable or poorly reviewed research. The main aim is often to earn money from publication fees, known as article processing charges.

These journals may use misleading practices to attract authors. For example, they may promise very fast review, provide little or no peer review, or present incorrect information about editors and publishers. The journal title and design may resemble well-established journals, which makes them difficult to recognise.

There is no clear definition of a predatory journal. You therefore need to assess journals and articles carefully. Use general criteria to decide whether a source is scholarly.

If you are a researcher and need to choose a journal for publication, there are additional guidelines to consider.

• Choose journal
  Information about ranking and open access agreements.
• Predatory publishers
  What to consider when choosing an open access publisher.
  

Assess the reliability of sources

Material used in scholarly work needs to be evaluated. The aim is to determine how reliable the studies are and whether the results may be incorrect or biased. Bias can arise from how a study is designed and conducted, how participants are selected, or how data is collected. A common way to assess reliability is to use a checklist.

SBU, the Swedish Agency for Health Technology Assessment and Assessment of Social Services, provides checklists for both quantitative and qualitative studies. Many are designed for systematic reviews.

Reviewing articles helps you understand the content and develop critical thinking skills.

• Critical appraisal tools and checklists
  Use SBU checklists to support your assessment of article reliability.

Assess grey literature

Grey literature is often more difficult to evaluate than material published in scholarly journals. It usually has not undergone traditional peer review and often lacks clear information about methods.

It is therefore important to apply source criticism. Use multiple sources to gain a more complete understanding of the topic.

• Assessment tools
  There are checklists that can help you evaluate grey literature. One example is the AACODS checklist, developed by the University of British Columbia.