Skip to content

References for Confidence Intervals

Curated resources to deepen your understanding of confidence intervals, margin of error, confidence levels, and interval estimation for proportions.

Wikipedia Articles

  1. Confidence Interval - Wikipedia - Thorough explanation of confidence intervals including correct interpretation, construction methods, and the relationship between confidence level and interval width.

  2. Margin of Error - Wikipedia - Covers the margin of error concept used in polling and surveys, explaining how sample size, confidence level, and variability affect the plus-or-minus range reported in studies.

  3. Standard Error - Wikipedia - Explains how standard error measures the precision of sample statistics, with formulas for proportions and means and the connection to confidence interval width.

Textbooks

  1. The Practice of Statistics by Daren S. Starnes and Josh Tabor - W.H. Freeman (2018) - Clear presentation of confidence interval construction and interpretation with AP-aligned examples, condition checking, and sample size determination formulas.

  2. Statistics in Action: Understanding a World of Data by Ann Watkins, Richard Scheaffer, and George Cobb - Key Curriculum Press (2008) - Activity-based approach to understanding confidence intervals through simulation and data exploration, helping students develop intuition before formulas.

Online Resources

  1. Understanding Confidence Intervals - Seeing Theory, Brown University - Interactive visualization showing how confidence intervals capture (or miss) true parameters across repeated sampling, demonstrating the correct interpretation of confidence level.

  2. Khan Academy: Confidence Intervals - Khan Academy - Video tutorials walking through confidence interval construction for proportions, with practice problems on interpreting intervals and determining sample size.

  3. AP Statistics Course Framework: Unit 6 - College Board - Official learning objectives and essential knowledge statements for confidence intervals, including the skills tested on the AP exam and common student misconceptions.

  4. Stat Trek: Confidence Interval Calculator - Stat Trek - Online tool for calculating confidence intervals for proportions with explanations of each step, useful for checking hand calculations and understanding the formula components.

  5. The Statistical Sleuth - American Statistical Association - Real-world case studies demonstrating how confidence intervals are used in scientific research, helping students see the practical applications beyond textbook problems.