Measuring reaction time with a ruler

• Cued by sight:

0. Create a spreadsheet to record the results of your experiment. Refer to Technical Hints to see how to create a spreadsheet.
   

1. Hold a metric ruler just above a partner's open thumb and index finger, with the lowest number on the ruler at the bottom. Provide a 2 cm separation between the thumb and the index finger. Drop the ruler without warning.

2. Record the number on the ruler where your partner catches the ruler. Take all measurements from above your partner's thumb. Refer to Technical Hints to see how to fill in a spreadsheet.

3. Use the chart below to determine your partner's reaction time. Record their reaction time on the spreadsheet.
   

4. Use the spreadsheet to calculate the mean reaction time for each type of drop. In the row next to "Mean", in each column, under sight, sound, and touch enter the formula to calculate the mean reaction time for all ten trails.Refer to Technical Hints to perform an average.

5. Create a new spreadsheet for yourself. Refer to Technical Hints to open a second spreadsheet. Record your drop distance and reaction time for ten trials.

• Cued by sound:

0. How does reaction time change when the cue is sound rather than sight? Have your partner close his or her eyes and wait for a sound you make (like a tongue click) just as you let the ruler drop?

1. Record your partner's drop time and reaction time for ten drops on separate spreadsheets. Calculate the mean reaction time for the ten trails.

2. Record your drop distance and reaction time for ten trials. Calculate the mean reaction time for the ten trails.

• Cued by touch:

0. Have your partner close his or her eyes again. This time, touch his or her arm lightly with your finger just as you let go of the ruler.

1. Record your partner's drop time and reaction time for ten drops on separate spreadsheet. Calculate the mean reaction time for the ten trails.

2. Record your drop distance and reaction time for ten trials. Calculate the mean reaction time for the ten trails.

Answer Question 1 and 2 in the "Analysis".

Using mean reaction times, create a bar chart to compare the data for sight, sound, and touch cues. Refer to Technical Hints to see how to create a bar chart.

Answer Question 3 and 4 in the "Analysis".