Random Samples
Date | February |
Class | Statistics |
Teacher | Janet Wineland |
Notes | We have been studying linear regression this semester. We did Double your pleasure and the Balloons. We also did Random Squares and Rolling Down the River to learn the importance of randomization. Next the students designed projects in groups of 2 or 3. When they collected their data they had to prove they did so in a true random way. Requirements for the project were a combination of things we used this summer. The following is the list of things they were to include and explain in their written and presented project:
I was impressed with the quality of their work. Their project data did not always give the best result but they still learned a lot about statistics. |
Date | November |
Class | 7th grade and 8th grade math students |
Teacher | Patti Bailey |
Notes | Random Rectangles |
Date | November |
Class | Probability and statistics class |
Teacher | Janet Wineland |
Notes | We had studied comparing 2 variables including correlation coefficient and linear regression lines. This month they were to come up with a project question, conduct a survey and report their results. Before we started the project I wanted them to realize the importance of random sampling. We first did the Random Rectangles activity. I really liked the lab worksheet with this activity. It made it clear about the difference between subjectively and randomly chosen rectangles. An added bonus was the part showing the importance of sample size. I liked the way it demonstrated the Stratum and Cluster methods. I think the students got a much clearer picture from this. We also did the Rolling Down the River exercise. This really made the differences between convenience, simple random and stratified clear for all of my students. Next time I would allow more time to “explore” the answers. Because of these activities, I was pleased with their linear projects. It was obvious they spent more time thinking about sampling techniques. |
Date | October |
Class | |
Teacher | Stephanie Reynolds |
Notes | Students were given the Random Rectangles Data Sheet. They were to subjectively select five rectangles and find the area. Then they were to find the mean area. As a class, we collected the means from each student. We found the class mean, median, and quartiles 1 & 3 so that we could then make a line plot & box & whisker plot. We then compared the subjectively found areas to a true random selection. The problem that I experienced was that my first class selected rectangles that gave almost the exact same values as a true random sample. The point was to show them that we don’t do a good job of selecting true random samples, but they actually did. In the future, I might combine data from more than one class so that the subjective random and the true random will not be so close. |