**The point is to learn how to "pile up" values that are close together to provide a two-dimensional picture of the data.** This is the key idea on which much of the whole discipline of statistics is based.

- Use an individual value plot to remind you of putting points on a number line (from your elementary math classes.)
- Use a dotplot to see how the values "pile up" to form a frequency graph
- Histograms are generalizations of dotplots, where you "pile up" nearby data values by taking intervals of values to make a bar.
- Stemplots are sometimes used as a quick way of organizing the numbers.

More sophisticated choices are available in additional applets. The first applet in each column is the applet described above.

## Number Line |
## Dotplot |
## Histogram |
## Stemplot |

Watch stemplot and set various options.. Create stemplot and change rounding and splitting stems.. |

Boxplots are not frequency graphs in the same sense, because they don't "pile up" the values. They are graphical displays of summary statistics. (For more choices, follow the Instructions / Discussion from the link at the bottom of the applet.)

Bar graphs

- Vertical axis can be either frequencies or percentages
- The order of the categories (along the horizontal axis) can be changed.
- These differ from histograms in that the vertical bars do not touch each other.

Pie charts (circle graphs)

- Must have ALL values of the categorical variable included so that the percentages sum to 100%.
- Can be labeled with both frequencies of each value and percentages of each value OR just percentages alone.
- The order of the categories can be changed.

Home.

Make comments or ask questions about the applets or the web pages. Copyright