Develop a Search Strategy

A well-structured search strategy is your roadmap for identifying relevant literature and ensuring reproducibility in your review. This section breaks down the key steps, from defining your concepts to using advanced search techniques and documenting each stage.

1. Why a Search Strategy Matters

Before you begin, recognize that developing a search strategy isn’t a one-time event. It’s an iterative process of refining keywords, exploring databases, and balancing precision (fewer but highly relevant results) with recall (collecting the broadest set of pertinent studies). Thorough documentation of each step is crucial for transparency and potential future updates.

2. Formulate Your Question Clearly

If you haven’t already, start by formulating a clear, focused research question. For example:

“How are neurotechnology and brain-computer interfaces redefining our understanding of human cognition?”


Below you can see how separating your question into distinct components, e.g., neurotechnology, brain-computer interfaces, and human cognition helps you identify appropriate keywords, synonyms, and subject headings.

3. Identify Key Concepts & Generate Synonyms

Break your research question into core ideas and list out synonyms for each concept. A simple table can keep you organized:

Concept

Synonyms / Related Terms

Neurotechnology

“neural engineering,” “neurotech,” “neuroprosthetics”

Brain-Computer Interfaces

“BCI,” “brain-machine interfaces,” “BMI”

Human Cognition

“cognitive processes,” “mental functions,” “mind,” “thinking”

Librarian Tips:

  • Use multiple synonyms for each concept to capture articles using varied language or spellings.
  • Check controlled vocabularies (e.g., MeSH, Thesaurus in PsycINFO) for official subject headings that might be different from your keywords.
  • Iterate: You may discover new synonyms while scanning article titles/abstracts.

4. Check for Existing or Ongoing Reviews

Visit registries like PROSPERO or OSF to see if anyone else has registered a protocol on a similar topic. You can learn from their search approach or spot new keywords you haven’t considered!

5. Combine Concepts with Boolean Operators

Boolean operators AND, OR, NOT help structure your search logic:

• OR expands your search by including synonyms or related terms.

• AND narrows results by requiring all linked concepts to appear.

• NOT excludes terms (use it sparingly to avoid discarding relevant articles).

Example Boolean String:

(Neurotechnology OR "Neural Engineering" OR "Neuroprosthetics")
AND
("Brain-Computer Interfaces" OR BCI OR "Brain-Machine Interfaces")
AND
("Human Cognition" OR "Cognitive Processes" OR "Mental Functions")


This ensures the results address all three main concepts. If your initial set is too large, consider adding more specificity. If it’s too small, broaden your synonyms or reduce the number of ANDed concepts.

6. Translate Your Search Across Databases

Different databases may use different syntax and subject headings:

• PubMed: MeSH (Medical Subject Headings)

("Neurotechnology"[tiab] OR "Neural engineering"[tiab] OR "Neuroengineering"[tiab] OR "Neuroprosthetic*"[tiab] OR "Neuroprostheses"[tiab] OR "Neurotech"[tiab] ) AND ( "Brain-Computer Interfaces"[MeSH] OR "Brain-Computer Interface*"[tiab] OR "BCI"[tiab] OR "Brain-Machine Interface*"[tiab] OR "Neuralink"[tiab] ) AND ( "Cognition"[MeSH] OR cogniti*[tiab] OR "cognitive function*"[tiab] OR "cognitive process*"[tiab] OR "mental function*"[tiab] OR "executive function*"[tiab] OR "mental process*"[tiab] OR "memory"[tiab])


• PsycINFO: APA Thesaurus

(TX("neurotechnology" OR "neural engineering" OR "neuroengineering" OR "neuroprosthetic*" OR "neural prosthetic*" OR "neurotech")) AND (DE "Brain Computer Interfaces" OR TX("brain-computer interface*" OR BCI OR "brain-machine interface*" OR "Neuralink")) AND (DE "Neurocognition" OR DE "Cognitive Processes" OR DE "Cognition" OR TX(cogniti* OR "cognitive function*" OR "cognitive process*" OR "mental function*" OR "executive function*" OR "mental process*" OR "memory"))


• DE = APA Thesaurus descriptor (controlled vocabulary).

• TX = free-text search across title, abstract, and author keywords.

Librarian Tips:

  • [Mesh] ensures you capture subject headings.
  • [tiab] searches titles and abstracts for your chosen keywords.
  • Wildcard (e.g., cogniti*) picks up variations like “cognition,” “cognitive,” "cognitively," "cognitions."
  • Subject headings should be verified manually. If your topic is interdisciplinary, consider additional platforms like Web of Science.

7. Incorporate Filters & Limits

• Date Limits: If your topic (e.g., advanced neurotechnology) evolves rapidly, you may focus on a specific time frame. Just note that older seminal works might provide valuable context.

• Language Filters: Use if you read only certain languages, but be aware of the potential for language bias.

• Study Design Filters: Some databases have built-in filters for systematic reviews, randomized controlled trials, etc.

A balance is crucial: applying too many filters can exclude pivotal research.

8. Document Everything

Maintain a detailed record of:

1. Databases Searched & Dates (e.g., “Searched PubMed on April 20, 2024”).

2. Full Search Strings: Write down the exact logic (Boolean operators, synonyms, truncation, etc.).

3. Filters & Limits: Date, language, publication type, etc.

Note: Many journals require a reproducible search strategy for systematic reviews!

Document the Search

Keep detailed records of search terms, databases used, and the number of results.

Example Search Query Log
Query Database  Results Date
("Neurotechnology"[tiab] OR "Neural engineering"[tiab] OR "Neuroengineering"[tiab] OR "Neuroprosthetic*"[tiab] OR "Neuroprostheses"[tiab] OR "Neurotech"[tiab] ) AND ( "Brain-Computer Interfaces"[MeSH] OR "Brain-Computer Interface*"[tiab] OR "BCI"[tiab] OR "Brain-Machine Interface*"[tiab] OR "Neuralink"[tiab] ) AND ( "Cognition"[MeSH] OR cogniti*[tiab] OR "cognitive function*"[tiab] OR "cognitive process*"[tiab] OR "mental function*"[tiab] OR "executive function*"[tiab] OR "mental process*"[tiab] OR "memory"[tiab]) PubMed 96 Mar. 19, 2025
(TX("neurotechnology" OR "neural engineering" OR "neuroengineering" OR "neuroprosthetic*" OR "neural prosthetic*" OR "neurotech")) AND (DE "Brain Computer Interfaces" OR TX("brain-computer interface*" OR BCI OR "brain-machine interface*" OR "Neuralink")) AND (DE "Neurocognition" OR DE "Cognitive Processes" OR DE "Cognition" OR TX(cogniti* OR "cognitive function*" OR "cognitive process*" OR "mental function*" OR "executive function*" OR "mental process*" OR "memory")) APA PsycINFO (Ebscohost) 101 Mar. 19, 2025
Continued ...      


Export Your Results to Citation Management Tools: 

Select Databases

Some Key Resources:

AI-assisted Literature Discovery

1. Open Knowledge Maps: A Harvard supported open-source tool that generates visual knowledge maps that cluster related research papers by topics, enabling intuitive exploration of scientific literature.

2. ElicitAI: Searches across 125 million publications from the Semantic Scholar corpus, based on natural language query.

3. Research Rabbit: Facilitates literature exploration and visualization of study connections and research clusters.

4. Connected Papers: Maps related studies in a visual graph to support discovery of influential works and trends.