The attribute of interest is the average speed of light across all units in the target population. This example is unusual in that it was believed that the speed of white light is constant in a vacuum and so there is no variation in the value of the response variate from unit to unit in this target population.
Attributes can be numerical or graphical. For example, a scatterplot constructed using all units in the target population is an attribute. The coefficients of the least squares line fitted to this scatterplot and the residual variation around the line are numerical attributes.
A clear specification of the attributes of interest can resolve many issues.
Lord's paradox, as presented by
[29], is easily resolved by noting that it involves two different attributes. See our discussion to
Hand.