Evaluating experiments (research summaries)

Working scientifically

CCSS NGSS.SEP 3CCSS NGSS.SEP 6England: KS4 Working scientifically

Objective and success criteria

Students will: Evaluating experiments (research summaries).

I can answer questions on today's skill on my own, without help.
I can explain each step and say why it works.
I can check my answer and spot a mistake.

Before and after

Needs first: Independent, dependent and control variables; Drawing conclusions from evidence

Leads to: Comparing scientific explanations (conflicting viewpoints)

Materials: Simple equipment for a fair test, Results table template, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).

Warm-up · 6 min

Quick retrieval from earlier learning (Independent, dependent and control variables; Drawing conclusions from evidence). Students answer on mini whiteboards.
Show answers together and note who needs support in the main task.

Investigation: How does the height of a ramp affect how far a toy car travels? Which is the independent variable (the one you change)? (the same floor surface / mass of the bob / distance the car travels / height of the ramp) → height of the rampPrompt: Independent variable: the one you change. Dependent variable: the one you measure.
Results: the higher the ramp, the further the car rolled. Which conclusion fits? (Heavier cars always go further. / Increasing the ramp height increases the distance travelled. / The ramp height has no effect. / Lower ramps make cars go further.) → Increasing the ramp height increases the distance travelled.Prompt: A conclusion describes the pattern in the results.
Investigation: Does the temperature of water affect how quickly sugar dissolves? Which is the dependent variable (the one you measure)? (water temperature / time for the water to evaporate / mass of sugar / time for the sugar to dissolve) → time for the sugar to dissolvePrompt: Independent variable: the one you change. Dependent variable: the one you measure.

Hook · 6 min

Show a simple experiment with one thing changed and ask what makes it a fair test.
Share the objective: Evaluating experiments (research summaries). Read the success criteria together.

I do: model it · 12 min

Work through the example out loud, saying why you do each step, not just what you do.
Example: Experiment 1: A pendulum with a 0.5 kg bob was timed for 10 swings with string lengths of 0.25 m, 0.50 m and 1.00 m. Experiment 2: A 1.00 m pendulum was timed with bobs of 0.1 kg, 0.5 kg and 1.0 kg. In Experiment 2, which variable was changed on purpose?
Step 1: In Experiment 2 the different values are given for the mass of the bob.
Step 2: So the answer is: the mass of the bob
Answer: the mass of the bob
Pause after each step and ask a student to say what comes next.

We do: guided practice · 12 min

Do these together. Students try each step on whiteboards before you reveal it.
Use the hints as prompts rather than giving the answer.

Experiment 1: A pendulum with a 0.5 kg bob was timed for 10 swings with string lengths of 0.25 m, 0.50 m and 1.00 m. Experiment 2: A 1.00 m pendulum was timed with bobs of 0.1 kg, 0.5 kg and 1.0 kg. In Experiment 2, which variable was changed on purpose? (the mass of the bob / the temperature of the room / the string length / the time for 10 swings) → the mass of the bobPrompt: Look only at the description of Experiment 2.
Experiment 1: A student dropped the same ball from heights of 0.5 m, 1.0 m and 1.5 m onto a wooden floor and measured the bounce height. Experiment 2: The student dropped the same ball from 1.0 m onto wood, carpet and concrete. Which variable was kept constant in Experiment 2 but changed in Experiment 1? (the bounce height / the drop height / the mass of the ball / the floor surface) → the drop heightPrompt: What was tested in Experiment 1?

You do: independent practice · 17 min

Students work on the student sheet. Circulate and check the first two answers of every student early.
Students who finish: write a question of their own for a partner, with the answer.

The 8 questions are on the student sheet below, with answers in the key.

Exit ticket · 7 min

Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.

Experiment 1: A student dropped the same ball from heights of 0.5 m, 1.0 m and 1.5 m onto a wooden floor and measured the bounce height. Experiment 2: The student dropped the same ball from 1.0 m onto wood, carpet and concrete. In Experiment 2, which variable was changed on purpose? (the floor surface / the bounce height / the drop height / the mass of the ball) → the floor surfacePrompt: Look only at the description of Experiment 2.
Experiment 1: Magnesium ribbon was added to hydrochloric acid at concentrations of 0.5, 1.0 and 2.0 mol/dm³ at 25 °C, and the gas volume after 1 minute was measured. Experiment 2: The 1.0 mol/dm³ acid was used at 15 °C, 25 °C and 35 °C. Which variable was kept constant in Experiment 2 but changed in Experiment 1? (the colour of the magnesium / the temperature / the acid concentration / the volume of gas after 1 minute) → the acid concentrationPrompt: What was tested in Experiment 1?

Watch out for

Everyday meanings of words getting in the way of the science meaning: define key words explicitly.
Remembering facts without the reason: ask "why?" and "what is the evidence?"

Support and stretch

Support

Review first: Independent, dependent and control variables.
Use concrete materials: simple equipment for a fair test.
Give the first step of each question, or a partly worked example to finish.
Pair with a confident partner for the guided practice.

Stretch

Move on to: Comparing scientific explanations (conflicting viewpoints).
Explain a common mistake in writing and how to fix it.
Write a word problem that uses today's skill, then solve a partner's.

Homework and more practice

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-10.

Free lesson plan from eurekami.com/lesson-plan-builder

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Evaluating experiments (research summaries)

Name

Date

Score/ 8

1
Question 1
Experiment 1: A student dropped the same ball from heights of 0.5 m, 1.0 m and 1.5 m onto a wooden floor and measured the bounce height. Experiment 2: The student dropped the same ball from 1.0 m onto wood, carpet and concrete. In Experiment 2, which variable was changed on purpose?
- A. the floor surface
- B. the drop height
- C. the mass of the ball
- D. the bounce height
2
Question 2
A scientist tests a new fertiliser on 20 tomato plants. Another 20 plants get no fertiliser. What is the purpose of the second group?
- A. It is not needed.
- B. It is a control group to compare against.
- C. It increases the dependent variable.
- D. It makes the experiment faster.
3
Question 3
Experiment 1: Magnesium ribbon was added to hydrochloric acid at concentrations of 0.5, 1.0 and 2.0 mol/dm³ at 25 °C, and the gas volume after 1 minute was measured. Experiment 2: The 1.0 mol/dm³ acid was used at 15 °C, 25 °C and 35 °C. Which variable was kept constant in Experiment 2 but changed in Experiment 1?
- A. the colour of the magnesium
- B. the temperature
- C. the volume of gas after 1 minute
- D. the acid concentration
4
Question 4
Experiment 1: A pendulum with a 0.5 kg bob was timed for 10 swings with string lengths of 0.25 m, 0.50 m and 1.00 m. Experiment 2: A 1.00 m pendulum was timed with bobs of 0.1 kg, 0.5 kg and 1.0 kg. In Experiment 2, which variable was changed on purpose?
- A. the temperature of the room
- B. the time for 10 swings
- C. the mass of the bob
- D. the string length
5
Question 5
Hypothesis: "Plants grow faster in blue light than in red light." Which experiment tests it best?
- A. Identical plants under blue or red lamps of equal brightness, same water and temperature
- B. One plant in blue light outdoors and one in red light indoors
- C. Plants in blue light only
- D. Different species under the same lamp
6
Question 6
Experiment 1: A pendulum with a 0.5 kg bob was timed for 10 swings with string lengths of 0.25 m, 0.50 m and 1.00 m. Experiment 2: A 1.00 m pendulum was timed with bobs of 0.1 kg, 0.5 kg and 1.0 kg. Which variable was kept constant in Experiment 2 but changed in Experiment 1?
- A. the mass of the bob
- B. the temperature of the room
- C. the time for 10 swings
- D. the string length
7
Question 7
A study finds a result with only 3 samples. What is the best next step?
- A. Repeat with a larger sample
- B. Publish it as proof
- C. Change the data
- D. Use fewer samples
8
Question 8
Experiment 1: A student dropped the same ball from heights of 0.5 m, 1.0 m and 1.5 m onto a wooden floor and measured the bounce height. Experiment 2: The student dropped the same ball from 1.0 m onto wood, carpet and concrete. Which variable was kept constant in Experiment 2 but changed in Experiment 1?
- A. the mass of the ball
- B. the floor surface
- C. the bounce height
- D. the drop height

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Answer key: Evaluating experiments (research summaries)

1. A. the floor surface
2. B. It is a control group to compare against.
3. D. the acid concentration
4. C. the mass of the bob
5. A. Identical plants under blue or red lamps of equal brightness, same water and temperature
6. D. the string length
7. A. Repeat with a larger sample
8. D. the drop height