Lesson 4: 4.4 Inference for Sampling
Duration of Days: 3
Lesson Objective
Students will be able to explain the concept of sampling variability and the role of sample size in reducing the margin of error, and identify types of non-sampling bias (nonresponse, wording).
1. Why will two different random samples from the same school give different results?
2. How can the way a question is "worded" trick people into lying?
Sampling Variability
Margin of Error
Undercoverage
Nonresponse
Response Bias (Wording of Questions)
HSS-IC.B.4: Use data from a sample survey to estimate a population mean or proportion; develop a margin of error through the use of simulation models for random sampling.
SAT questions often include a "Margin of Error" in a footnote. Students must understand that the "true" value is likely within that range.
Even with "good" sampling, there is natural error. This section distinguishes between "unavoidable variability" and "avoidable mistakes" (like bad question wording).
The Problem: A poll asks: "Do you support killing innocent trees to build a new parking lot?"
Task: Identify the bias and explain how it will likely affect the results.
Selecting random samples does not guarantee all bias will be avoided.
Show students how a larger sample size "narrows" the sampling distribution using a digital applet.
Teacher assigns examples from the textbook and other resources.
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