Lecture Notes: Sampling and Populations

Overview

• Focus on sampling and populations this week.
• Complete Assignment 1: Download SPSS.
• Participate in discussion board, do readings, and watch videos.

Data Sets Used

General Social Survey (GSS)

• Samples U.S. population.
• Used for practicing methods from the textbook.

American Community Survey (ACS)

• Specific to California.
• Focus on the gender pay gap among those who work full-time year-round.
• Based on 2014-2018 data, updated periodically.
• Download from Course Materials for assignments.

Sampling Concepts

• Target Population: Entire group of interest.
• Samples: Subset of the population used for analysis.
• Random Sampling: Ensures equal chance of selection, reduces error.
• Sampling Error: Difference between sample mean and population mean.

Sampling Error Example

• Population Mean vs. Sample Mean: Example given with age differences.
• Larger sample size can reduce sampling error to an extent (Power Analysis).

Importance of Sampling Error

• Influences statistical concepts like Standard Error, Confidence Intervals, and Margins of Error.
• No need to understand math in-depth for this course.
• Resources for further learning: Statistics courses, Khan Academy.

Tools and Resources

• SPSS for calculating and interpreting statistics.
• Companion website for GSS files.
• Error reporting in surveys for understanding sampling error.

Instructions

• Download ACS and GSS files from designated platforms.
• Contact instructor via email, call, or text for help.

Additional Notes

• A focus on understanding statistical application rather than detailed calculations.
• Optional deeper exploration of statistical math for interested students.