A guide to searching for alternatives to the use of laboratory animals

This resource is currently (August 2016) being updated. New links will appear here over the next few weeks.


The ability to access and implement information on the Three Rs (Replacement, Reduction and Refinement) is essential for ethical and scientific reasons, because it can lead to improvements in animal welfare and scientific outcomes, as well as to saving resources. It can prevent unnecessary duplication of studies, improve experimental design, and ensure that existing and new alternative methods are used as widely as possible.

In addition, the new EU Directive 2010/63/EU on the protection of animals used for scientific purposes, stipulates that the principles of the Three Rs should be implemented and that project evaluation should assess compliance with this requirement. It also includes the condition that EU Member States should contribute to development and evaluation of alternative approaches, including promotion of those approaches and dissemination of any related information. Therefore, it is important to consider whether Three Rs information is readily available and whether scientists are effectively accessing it.


To help scientists effectively to find and make use of all Three Rs information relevant to their proposed experimental study, this guide provides an introduction to the basic principles of searching for such information. It assumes no previous knowledge of search techniques or of the facilities available for obtaining information from the Internet. It acts as a starting point for scientists, giving advice on terminology, correct strategies and available resources for efficiently conducting internet-based searches. When further in-depth or specific guidance is available this is highlighted and links are provided.


The guide is presented as a series of pages, listed below under What information is offered here?, and accessible from links found there. Some of the links are internal, leading to other pages in the guide; others are links to external websites.

Although every effort is made to ensure all links are up-to-date we welcome any suggestions for new, relevant ones and feedback if any are found to be unreachable.

You may find it useful to add some of these links to your own bookmarks. That can be done by right-clicking on the link and selecting “add to favourites” or “add bookmarks”, depending on the browser used.

What information is offered here?

Search basics

Basic principles applying to the construction of search filters for use on Internet search engines or on any on-line database are described here. This includes general considerations relating to the choice of search terms and to the use of operators to define the links between the terms.
Link to Search basics page

Conducting a search

This section focuses on performing a literature search in bibliographical databases but much of the information will be applicable to search engines. It provides suggestions for how to approach and report a search on the Three Rs, including a list of terms relating to reduction, refinement and replacement and information on maximising the number of relevant papers you find.
Link to Conducting a search page

Mailing lists and discussion forums

A comparison of selected Internet search engines and meta-searchers, including what to consider when choosing which one. It can be difficult to retrieve Three Rs information from traditional bibliographic databases, because scientific publications generally do not include specific details about procedures, animals and husbandry in their titles or abstracts. Another way to find such information is by making less formal enquiries to other scientists and/or technicians, so this section gives a description of Internet resources for enabling such peer-peer communication. to use.

Free databases

A description of some of the databases which can be freely accessed from the Internet, together with brief guide notes on how to perform searches within some of these databases.

Accessing the invisible web

This section provides information regarding specialised resources that make it easier to access the ‘Invisible Web’ (also referred to as the ‘Deep Net’, ‘Deep Web’or ‘Hidden Web’), which is the part of the Internet that is not searched by standard search engines (e.g. subscription databases requiring registration and sources containing documents in formats that are not accessible to the common search engines).

External links

Useful links to external resources and literature of relevance to the Three Rs, searching, sharing information and to the use of the Internet.