Final answer:
The yard stick test is a direct method of measuring reaction time that depends on a person's ability to catch a falling ruler, using the measurable distance the ruler falls to calculate the reaction time.
Step-by-step explanation:
The yard stick test is considered a direct measurement of reaction time because it evaluates how quickly an individual can respond to a visual cue with a motor response, which in this case is catching a falling ruler. When the ruler is dropped, a person's reaction time is how long it takes them to respond to the visual signal of the moving ruler and to physically stop it with their fingers. The distance the ruler falls provides a measurable distance that, when combined with the known acceleration due to gravity, allows the calculation of reaction time without the need for electronic devices.
This direct measurement is useful because it removes many of the delays associated with more indirect methods of measuring reaction time, like the use of a stopwatch, which can be affected by one's personal anticipation or delay in pressing the button. The measurement taken from the point on the ruler where it is caught indicates how far the ruler traveled during the subject's reaction time, which can then be converted into time taken to react, providing an immediate and tangible measure of reaction time.