The "behavior centered" approach starts by comparing behavior across linguistic groups and then searches for causes for that behavior in the linguistic system. Whorf attributed the occurrence of fires at a chemical plant to the workers' use of the word 'empty' to describe the barrels containing only explosive vapors. Bloom noticed that speakers of Chinese had unexpected difficulties answering counter-factual questions posed to them in a questionnaire. He concluded that this was related to the way in which counter-factuality is marked grammatically in Chinese. Other researchers attributed this result to Bloom's flawed translations. Strømnes examined why Finnish factories had a higher occurrence of work related accidents than similar Swedish ones. He concluded that cognitive differences between the grammatical usage of Swedish prepositions and Finnish cases could have caused Swedish factories to pay more attention to the work process while Finnish factory organizers paid more attention to the individual worker.