IOE 433 Occupational

T. Armstrong
U of Michigan

Reaction Time Exercise - How Fast Are You?


  1. measurement of reaction time
  2. effect of body part on reaction time
  3. effect of distance on reaction time
  4. effect of weight on reaction time
  5. effect of gender on reaction time


Measure reaction time as the distance that a ruler drops before a subject can grasp it
  1. Position the subject with the elbow at the side of their body, their forearm horizontal and semipronated
  2. Hold a ruler even with (long axis up/down) even with the top of the subjects thumb and forefinger
  3. Instruct the subject to catch the ruler when you release it
  4. Calculate the reaction time from the distance that the ruler drops (t=(2d/g)0.5)

Reaction Time Caluclator:

distance, time

  1. distance between fingers)
  2. weight
  3. counting down
  4. gender
  5. age


  1. Compare the reaction times across conditions. Explain the difference between each condition.
  2. List the physiolgical events that occur as when subjects try to catch the dropping weight?
  3. Can you redesign this task to improve a workers performance?
  4. How much time would ou need to reach and grasp a hand hold if you slip?

Reference: Woodworth, George G. Biostatistics: a Bayesian introduction. Vol. 499. Wiley-Interscience, pp. 47-61, 2004.


Van Cott, Harold P., and Robert G. Kinkade. "Human engineering guide to equipment design." (1972).

Lee, John D., Christopher D. Wickens, Yili Liu, and Linda Ng Boyle. Designing for people: An introduction to human factors engineering. CreateSpace, 2017.