Measuring well and showing your results
How reliable is the ruler-drop test?
Can you trust reaction-time measurements made with a dropped ruler?
Watch first
An English teaching video on this topic from Miacademy & MiaPrep Learning Channel. Watch it, then scroll down for the lesson.
What you need
Tick each one as you find it — 0 of 4 ready.
Plan the fair test
- Change: Which catch number this is (1 to 10)
- Measure: Catch distance in cm
- Keep the same: Same ruler, same partner, same starting position, no countdown before the drop
Objectives this evidences
- Make and record observations and measurements using a range of methods, and evaluate the reliability of methods
- Present observations using appropriate methods, including tables and graphs, and communicate ideas using scientific terminology
Do it, one step at a time
Step 1 of 4
- Step 1. Your partner holds the ruler at the 30 cm mark so it hangs between your open finger and thumb at zero. Without warning, they drop it, and you catch it.
- Step 2. Record the catch point in centimetres. Repeat ten times, swapping the hand you catch with after five.
- Step 3. Calculate the mean and the range for all ten catches, and mark any result that looks like an anomaly.
- Step 4. Write one sentence judging the method: how precise is a ruler marked in millimetres for measuring something this fast, and how could you improve reliability?
What should happen
Readings scatter widely because the method depends on human timing. Repeats tighten the mean but cannot fix the method itself.
Think about: Your data is honest but imprecise. What instrument would measure reaction time to a hundredth of a second instead?
Write up your result
A sentence or two is enough to save it.
The lessons behind this practical
Each one opens with the same short film, and the film has a written transcript underneath if reading is easier than watching.
Now the quiz for this topic
Questions come from the lessons behind this practical, so nothing is asked that has not been taught.
Quiz
Measuring well and showing your results quiz
4 questions from the lessons in this stage. No timer, and you can try again as many times as you like.