1. Tell the students that the CyberSquad is trying to locate Hacker's castle, where Dr. Marbles is hidden. In Castleblanca, there are too many castles to check, so the CyberSquad conducts a survey asking people to put a mark on a map where they have seen a tall man with a pointy chin and cape. Based on the data, they find Dracula not Hacker.

2. Tell the students that they will see a video segment in which the CyberSquad tries to figure out how to find Hacker instead of Dracula.

3. Show the Using Data Clusters to Find Hacker QuickTime Video, and ask students to keep track of as many things as they can, which can make one's data set lead to the wrong predictions or conclusions.

4. Discuss the students' ideas.

5. Distribute the Handout: "What's Typical, Based on the Shape of Data Charts?".

6. Ask students to examine the data collected by Inez and Matt and to answer the questions.

7. Discuss their answers, noting that the two data sets differ only by one inch, suggesting perhaps that one kid measured the band members with their shoes on and one kid measured them with their shoes off. This is a systematic error in data collection.

Assessment: Level A (proficiency): Students are asked to examine a table of data showing the average number of hours of sleep for males and females in different age groups, and to identify the range, mode, and some other characteristics of the data set.

Assessment: Level B (above proficiency): Students are asked to examine a scatter plot of data showing records of the speed of cars and the time of day they were recorded along a certain stretch of road, to identify clusters of data, and to decide when it would be best to set up a speed trap.