Measuring accurately and judging reliability
Numbers only mean something if you trust how they were collected. Reliability is about whether you'd get the same answer again.
Part of your national curriculum
- Working scientifically: Make and record observations and measurements using a range of methods, and evaluate the reliability of methods
Lesson overview
What you'll learn in this lesson
Make and record observations and measurements using a range of methods, and evaluate the reliability of methods
Key learning points
- • Choosing the right instrument
- • Repeating readings
- • Judging reliability
This lesson at a glance
- 25 minutes
- 17 parts to scroll through
- 3 quick checks
- Marked quiz at the end
- Gentle pace: short sittings with pauses
Words to know
Scroll down — the lesson carries on below
Watch & discover
Part 1 of 17
Visual introductionPicture this
Measuring accurately and judging reliability
Numbers only mean something if you trust how they were collected. Reliability is about whether you'd get the same answer again.
In a nutshell
Make and record observations and measurements using a range of methods, and evaluate the reliability of methods
Learning cycle
Part 2 of 17
Learning cycle 1 of 2
Part 1 · Choosing the right instrument
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 3 of 17
Learn
Choosing the right instrument
A measuring cylinder gives finer volume readings than a beaker; a data logger with a thermometer probe can record temperature every second, more precisely than a person reading a thermometer by eye. Choosing sensitive, appropriate equipment reduces error.
Reset break
Part 4 of 17
Pause
That's sitting 1 of 4 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Explore the idea
Part 5 of 17
Learn
Repeating readings
Taking repeat measurements and calculating a mean reduces the effect of random errors — small, unpredictable variations. If one reading is very different from the others (an anomaly), it can be identified and excluded before averaging.
Quick check
Part 6 of 17
Quick check
Part 7 of 17
Reset break
Part 8 of 17
Pause
That's sitting 2 of 4 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Learning cycle
Part 9 of 17
Learning cycle 2 of 2
Part 2 · Judging reliability
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 10 of 17
Learn
Judging reliability
A method is reliable if repeating it gives similar results each time. Close, consistent repeat readings suggest high reliability; widely scattered readings suggest the method needs improving, perhaps with better control of variables or more precise equipment.
Quick check
Part 11 of 17
Reset break
Part 12 of 17
Pause
That's sitting 3 of 4 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Challenge round
Part 13 of 17
Game · Sort it
Which of these are true?
Drag each card into the right column. Tap a card first if dragging is fiddly.
True
Not true
Challenge round
Part 14 of 17
Game · Fill the gaps
Finish the sentences
Choose the word that belongs in each gap.
A measuring cylinder gives finer volume readings than a beaker; a data logger with a thermometer probe can ____ temperature every second, more precisely than a person reading a thermometer by eye.
Taking repeat ____ and calculating a mean reduces the effect of random errors — small, unpredictable variations.
Close, consistent repeat readings suggest high ____; widely scattered readings suggest the method needs improving, perhaps with better control of variables or more precise equipment.
Challenge round
Part 15 of 17
Game · Recall cards
What does repeating an experiment and averaging help reduce?
Card 1 of 4
Mastery quiz
Part 16 of 17
Marked quiz
End of lesson quiz: Measuring accurately and judging reliability
4 questions, marked with the reasoning shown. No timer.
1. What does repeating an experiment and averaging help reduce?
2. An anomalous result is one that is:
3. A method is reliable if:
4. Random error is reduced by
Lesson round-up
Part 17 of 17
Lesson round-up
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Ask LunaPart 1 of 17 · Watch & discover
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Make and record observations and measurements using a range of methods, and evaluate the reliability of methods