a collocation is a sequence or combination of words that occur together more often than would be expected by chance (from Wikipedia|Collocation) A collocation, e.g. fatal error, typically consists of a node (error) and a collocate (fatal). Collocations can have different strengths, e.g. nice house is a weak collocation because both nice and house can combine with lots of other words, on the other hand, the Opera House is a strong collocation because it is very typical for opera to occur next to house and, at the same time, opera does not combine with many other words. In Sketch Engine, the tool to use for collocations is the word sketch. The strength of collocation is expressed by the logDice score.