Bar+Graphs+with+Numeric+Data

Bar graphs are used to organize data into rectangles. There are a few different types of bar graphs that can be made in TinkerPlots.

**Case-Value Plot of heart rate for 12 people**
This plot can be confusing for students because the vertical axis is not a frequency/count. The length of the bar drawn for each data value represents the actual data value. For example, the first person has a heart rate of approximately 72 beats per minute. The data for 12 people is shown in no particular order. I discourage the use of the case-value plot.

**Dot Plot / Fused Dot Plot**
The same data is show below in a dot plot and a bar graph (I call this a fused dot plot). The bar graph was created by fusing the dots together. While the second plot is a bar graph, I do not use fused dot plots because it is difficult to see the count. **The dot plot allows us to see each individual case.**

**Histogram**
A histogram is used for numeric data that can assume any value in a range. The data for this set of 12 people is shown below. There are six bins ranging from 68 to 86 with a width of 3 beats per minute. The count is marked on the vertical axis. The data from the dot plot is first clustered in bins, then the dots are fused. The plot below has dots divided into six bins (the icons not fused). Note that this is **not a dot plot** because there are intervals instead of a number line along the horizontal axis. Note: The lower value was changed from the default setting of 69 to 68 beats per minute.


 * All but 12 cases were deleted.**
 * Attribute Description**

Gender: Gender of person Temperature: Body temperature (degrees Fahrenheit) HeartRate: Number of heart beats (per minute)

These data are based on a data set presented in Mackowiak, P. A., Wasserman, S. S., & Levine, M. M. (1992), "A Critical Appraisal of 98.6 Degrees F, the Upper Limit of the Normal Body Temperature, and Other Legacies of Carl Reinhold August Wunderlich," Journal of the American Medical Association, 268, 1578-1580.