Define a Measure

How To... > Work with Collections > Define a Measure

When you’re looking at data, there are usually some numbers you would like to compute that apply to the collection as a whole -- the sum of the salaries, the median of the weights, the ratio of the second year’s yield to the first year’s, or the correlation coefficient. These numbers are all statistics, or measures. You define measures in the collection’s inspector by giving new measures a name and (usually) a formula. In formulas that apply to that collection, you can refer to measures by name.

The most common reason for defining measures is to collect measures from repeated sampling or rerandomization.

1.	Double-click the collection to show its inspector.

2.	Go to the Measures panel.

3.	Click <new> and type a name for the measure.

4.	Enter a value for the measure or double-click the measure’s Formula cell and enter a formula that defines how the measure is calculated.

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If you have defined a measure to build a sampling distribution, you can collect measures by dropping a measure’s name on an empty collection. Each measure becomes an attribute in the measures collection.