Bradley’s dad walks by his son’s room, and the door is wide open. Suddenly, Mr. Landen stops and gives Bradley a stern look, “Your room is a total wreck, and you’re planning on having friends over this weekend?” Bradley thinks about what his dad has said. He remembers that he invited some new friends over—people who don’t know him very well yet. Bradley sighs and begins to clean his room.

What happened? Bradley made a decision—and a good one, too—that it would be embarrassing for his new friends to see his room looking like an ogre’s lair or a room that had just been raided by the FBI. But first he examined the facts—his wrecked room, his interest in impressing his new friends—and drew a conclusion about what undesirable thing might happen. A conclusion is a judgment, decision, or understanding of something that is based on facts. Drawing conclusions requires you to look at all the evidence and then make a decision based on what you know.

Here’s another example: Say you’re researching shark attacks, and you read that most attacks in the U.S. happen in Volusia County, Florida. You find out that the beaches there have more people in the water than any other beaches in Florida, and that these waters also have a thriving shark population. One victim reported that when he was bitten on the hand, he was paddling his surfboard in murky water with lots of smaller fish nearby—fish that are a food source for sharks.

In another study, however, you read that humans are not normally part of a shark’s diet. Based on the information in both of your sources, one conclusion you might draw is that sharks attack people because they mistake body parts, such as arms and legs, for the fish they normally eat.