‘I want to find out about the environment or environmental – impact, effect or consequence of – GM or genetically modified crop or crops.’

• First of all we would take out the ‘I want to find’ – we wouldn't type that into a database.
• We might try ‘crop/crops’ and ‘environment/environmental’ with truncation. We might get words like environmentalists too that we hadn't thought of previously.
• We would probably try ‘genetically modified’ as a phrase because it is quite specific and will help to narrow our search down.
• Because we've used alternative terms – ‘impact’, ‘effect’, ‘consequence’ – we will need to use OR to broaden our search.
• Finally we will need to use AND to bring the search together – we are looking for records which are about the environment as well as about the impact, and as well as about GM crops.

If we were to write this search out in full using the language of databases, specifically as required by ROUTES, it might look something like:

environment* AND impact OR effect OR consequence AND GM OR "genetically modified" AND crop*

In order for the search to work properly in some databases you would need to separate each set of search terms with brackets, to make sure that the database processed the right search terms together, and in the right order. For example:

(environment*) AND (impact OR effect OR consequence) AND (GM OR "genetically modified") AND crop*

In most databases these days, however, you will be able to enter the groups of search terms in separate boxes, which do the same job as brackets.

You would only need to carry out a search as thorough as this if you were doing an extensive piece of research. This is quite a complicated search and some smaller databases, such as ROUTES, might not be able to process it. You would probably only need to combine a couple of the search terms to get some relevant results, e.g. environment AND effect AND "genetically modified". It is perfectly acceptable to alter the search, adding words in or taking words away: you can keep testing it until you find the results you are looking for.