Explore ToolsStatLens

Interactive tools for exploring and summarizing data.

• One Quantitative Variable

  Summary statistics, histograms, dotplots, and boxplots for a single numeric variable.

• One Categorical Variable

  Bar chart and frequency table for a single categorical variable.

• Two Quantitative Variables

  Scatterplot with regression line, correlation, R-squared, and residual plot.

• Two Categorical Variables

  Contingency table with proportion toggles and grouped bar charts.

• Compare Groups

  Side-by-side boxplots, dotplots, or histograms comparing a quantitative variable across groups.

• Dotplot Editor

  Click to add and remove points on a number line. Mean, median, SD, and IQR update live.

• Regression by Eye

  Drag a line to fit a scatterplot, see the residual squares, then compare your fit to the least-squares line.

• Scatterplot Editor

  Drag, add, and remove data points and watch the least-squares line, r, and R² respond — feel leverage vs. influence.

• Data Explorer

  Load a dataset, select variables, and choose your own visualization. Practice the EDA workflow.

• Are You Psychic?

  Predict coin flips to test your "psychic" powers, then use simulation to see if your result could be due to chance.

• Stump the Chump

  Try to fake a random coin-flip sequence, then compare it to a real one. Can you fool the computer?