boxplots NLVM

the 'Old Faithful' geyser in Yellowstone Park has data for the intervals between eruptions that are sort of bi-modal















boxplots NLVM

enables a comparison to be made between a boxplot and the shape of a bar chart (of grouped data)

several data sets are provided - the 'Old Faithful' data set having 112 points

the group sizes can be changed with a slider

students can decide how many groups to have - to provide an overview of the data shape













students can enter their own data and compare a boxplot with a bar chart
they can also see how their data looks with easily changed class intervals (by means of a slider)

histogram (bar chart) tool - Illuminations (NCTM)

Illuminations histogram tool

6 data sets given, or you can enter your own data

it is very helpful to be able to explore the shape of the distribution for various groups sizes (using a lovely slider)

students can consider the number of bars necessary to provide a view of the overall data shape

for example, in the 'horsepower' example above, a distribution with a further peak (as well as the modal class) gets smoothed out for fewer 'bins'