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Today (3/31/10) we continued our lesson from last time (Going the Distance, see the curriculum provided online for details). We had noticed that some of the students had trouble graphing their time versus distance measurements so we decided to do a quick review on scatter plots. We projected graph paper on the board and discussed elements necessary for complete graphs (scale, labels, title, etc.). We graphed several sample points and explained how they would measure the mystery distance and use their graphs to find the amount of time they should program their cars to go. Each group decided on a time to program their cars and created the simple program they had used last time.

Everyone then lined up to complete the final test! Only one group was successful on the first try. Many of the students had not measured the distance consistently, or plotted their graph correctly. Each group was allowed to redesign their programming and re-test their cars. Even so, only a few of the cars made it the mystery distance.

We then concluded the activity with a discussion of what problems they had run into and what observations they made. We decided that unless your graph and measuring is completely accurate it is better to run your car at a lower speed to ensure less over or undershoot.

We had a few minutes left and decided to jump right into the next activity--Harry Potter's Platform 9 and 3/4. We explained that humans use their senses to determine where they are going, but NXTs use touch and light sensors. We explained the challenge and then discussed ambient versus reflected light measurements. The students changed their partners and modified the cars to include the light sensors. They then used the "view" technique to measure reflected light. Next week we will wrap up the Platform 9 and 3/4 activity. Overall, "Going the Distance" was very successful, the students are becoming very proficient at programming!