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Data Sampling: Representing Many by Sampling Some is an interactive tool designed to help students understand why it is important to select representative samples when attempting to draw conclusions about the population as a whole.
The tool contains four modules of the same skill level covering four “policy issues” in a small town: Skate Park, Pet Insurance, Summer Concert Series, and Public Computer Center. After choosing an issue, users select one of four related policy questions. They will then survey three different population samples, the parameters of which the user sets (sample size, population segment, and confidence level are adjustable*). Then, a statistically valid representative sample as well as the results of the entire population will appear for comparison. Questions are provided to aid students in thinking critically about the meaning of the results.
*More Information about Sampling Parameters in the Tool: Samples are based on a margin of error of ±5% throughout. The sample-size sliders are generally limited to a portion of the population (except in cases of population segments that are already quite small). In the context of the storyline (as the introduction on the homepage sets up), the Statsboro government has limited time and budget for surveying. Within these constraints, the sliders are designed to give the opportunity to select not only accurate representative samples but also flawed (too small) samples, so that students can have the learning experience of comparing the varied parameters and results.
Ideas for Classroom Use
- Accompanying Interactive Lesson:The tool is integrated into a flexible, multipurpose interactive lesson on representative samples. The lesson includes worksheets, additional connections to real-world sampling, sample discussion questions, pointers on developing exemplary math thinking, a standards chart, and more.
- Whole-Class Instruction: The tool can be used on a whiteboard as part of a whole-class lesson on selecting representative samples.
- In-Class Project or Homework:Individual students or small groups can be assigned a survey issue(s) to work on independently.
- Critical Thinking:Using the reflection questions that appear at the end of each survey, or assigning your own, will enable students to deepen their understanding of the applicable statistics concepts. The intent is to get students to go beyond thinking about what the results are and consider what the results mean. The questions can be used to prompt discussion or writing. Although responses to the questions will vary, some possible answers are included in the Answer Key.
Related Interactive Tools
- Data Displayer:Use this data-analysis classroom tool with your students to calculate and graph data. Functions include: mean, median, and mode; box-and-whisker plot; scatterplot; and standard deviation. Preset data is provided (in the themes of movies, sports, and agriculture), and custom data can be entered as well.
- Probabilities Tour and Probability Lab:In the Probability Lab, students explore the difference between theoretical probability and experimental probability by running their own probability experiments. In the Probabilities Tour, students will consider both theoretical probability and potential financial rewards to help plan a concert tour for a band.
Free Math Lessons, Worksheets, and Interactives
Explore the rest of the Expect the Unexpected With Math® series at
scholastic.com/unexpectedmath.