• ### Survey Design

This site takes the user through the steps and decisions necessary when designing a survey. Pros and cons for each method are outlined and other issues in survey design are presented.
• ### Design of Experiments & ANOVA

This site lists definitions of key terms related to experimental design and ANOVA, including factorial, blocking, interaction, and others. This site is part of the "Statistics Glossary" for the STEPS project (STatistical Education through Problem Solving).
• ### Factorial Design

This site explains the 2x2 factorial experimental design, it's components, and it's effects. Graphs illustrate the concepts discussed.
• ### Confidence Intervals for Means Applet

This applet simulates finding confidence intervals for the mean of a normal random variable. A sample of size 20 is generated from a standard normal random variable. The blue marks represent the sample data. The sample mean X and sample standard deviation s are found and used to calculate the confidence interval. The black intervals are the confidence intervals which include the true mean 0, and the red intervals are those which exclude 0. This applet needs to be resized for optimal viewing.
• ### Easy Charts: Java Chart Components

EasyCharts is a complete library of java chart components, chart applets, and chart servlets that enable programmers to add charts and graphs in java applications, web applications, and web pages with just a few lines of code. The java chart library includes bar charts, line charts, and pie charts and is highly configurable. The java chart library supports charts with multiple data series, overlay charts, drilldown charts, and interactive features such as zooming and scrolling of chart data.

• ### Analysis Tool(s): StatCrunch

This web-based package does a very complete range of statistical calculations designed to be user friendly. Formerly known as WebStat, it provides statistical calculation functions that would be done in most introductory statistics courses. Notable examples include being able to create histograms, pie charts and boxplots, calculation of summary statistics and confidence intervals, and performing hypothesis tests. It allows data to be entered in a spreadsheet style data window or opened from a file. Cost for students and professionals is \$13 for 6 months and \$23 for 12 months (instructors have complimentary access), and it does require a login. Key Word: Calculator.

Stat Crunch's Available Features:  https://www.statcrunch.com/assets/documents/StatCrunch%20Statistical%20Procedures.pdf

• ### HyperStat Online: Ch. 4 Introduction to Probability

This chapter of the HyperStat Online Textbook presents six sections on probability including conditional probability, unions, intersections, and the Binomial distribution. A link to exercises for the chapter is available, as well as a link to an applet that demonstrates the approximation of the binomial with a normal distribution (in section 5).
• ### Z-test for difference between means

A slideshow presentation with two good examples on using the Z-test for the difference between two means. Gives some good "plain language" interepretations of what "statistically significant difference" means.
• ### Research Methods Knowledge Base : The t-Test

This particular textbook lesson addresses the independent t-test. It presents to the user how to compute the t statistic and then how to interpret the results.
• ### Student's t-test Applet

This page gives a short background on Student's t-test and provides three t-test calculators. Two perform t-tests for independent groups and one performs t-tests for matched pairs. Users type in individual data points or copy and paste the entire data set. Some examples are given for demonstration.