<span>Bear-proof trash cans have been shown to be effective in other towns in this state. This reasoning is VALID because it provides evidence that bear-proof trashcans are effective.
If we want to show that we keep up with the latest methods, we need to require bear-proof trash cans. This reasoning is INVALID because it does not prove these types of cans would do anything to prevent bears from getting in them. This argument has more to do with "showing" people the town can "keep up."
If we can spend money on schools and the fire department, we can also spend it on bear-proofing. This reasoning is INVALID because, in order to spend money on something, it must be proven effective. This argument does not prove that bear-proof cans are effective; it merely says money should be spent on them because money is also spent on other things.
Last year, a tourist in town was mauled by a bear on trash day. This reasoning is VALID because there appears to be a connection between the tourist's d</span>eath and the trashcans. In this case, the bear would have known that trash day = food day, and so the bear was invading human space that day and came into contact with a tourist. With bear-proof cans, bears would no longer associate trash with food, and so these types of incidents could be prevented.
