An experiment was performed to compare the reaction time to

An experiment was performed to compare the reaction time to two types of traffic signs. One sign type is Prohibitive (e.g., No Left Turn) and the other sign type is Permissive (e.g., Left Turn Only). Ten drivers were used in the study. Each driver was presented with 40 traffic signs, 20 of each type, in a random order. For all 40 signs, reaction time was recorded and the mean of each sign-type calculated.

Is this paired data or two independent samples?

Solution

This is an example of Paired Data, as the data for each type of sign can be linked by the driver.

There are 10 drivers, and for each driver we compare the reaction time for the 2 different signs.

So it is a Paired Data set.