There used to be a really good site called Boolify several years ago, which had a drag and drop approach to building searches. You simply clicked on a building block such as 'word' or 'not' and dropped it into the work area, adding in your terms as you went. The search was then mirrored for you in a search box, and was then executed. Boolify died but has been taken over and resurrected by Kidzsearch and you can find it on their website here: https://www.kidzsearch.com/boolify/ It's still very simple to use, though it can be a little bit fiddly to get the blocks in the right order, and it does add in unnecessary double quotes, but it's a good approach to getting children (and maybe novice adult searchers) to think about search construction. The limitation as far as adults are concerned is that it does only search the children's search engine, which isn't a criticism, just an observation. I've attached a screenshot, so you can see exactly what I mean.