Experimental Designs
Speed Kills
The Ministry of Transportation is interested in whether highway fatalities have changed before and after increasing the speed limit. The total number of highway fatalities a year before the speed limit change were calculated and the total number of highway fatalities a year after the speed limit change were calculated. It was found that the number of fatalities was greater when the speed limit increased.
This is an example of...
The variables in this example were manipulated (speed limit), so it can't be non-experimental.
There was NO random assignment, The participants had already driven the roads.
Good. The participants already had completed the drive and could not be randomly assigned.