• Quick retrieval from earlier learning (Evaluating experiments (research summaries)). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

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? (the floor surface / the drop height / the mass of the ball / the bounce height) → the floor surfacePrompt: Look only at the description of Experiment 2.
2. 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? (the string length / the temperature of the room / the mass of the bob / the time for 10 swings) → the string lengthPrompt: What was tested in Experiment 1?
3. In a drug trial, neither the patients nor the doctors know who gets the real drug. Why? (To save money / Because the drug is secret / To stop expectations from biasing the results / To make the trial shorter) → To stop expectations from biasing the resultsPrompt: People's beliefs can change what they report.

• Show a simple experiment with one thing changed and ask what makes it a fair test.
• Share the objective: Comparing scientific explanations (conflicting viewpoints). Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: Two students explain why a ball rolling on a flat floor eventually stops. Student 1: Objects naturally slow down and stop when nothing keeps pushing them. Student 2: Friction and air resistance act against the motion; with no resistive forces, the ball would keep moving at a steady speed. Which student's view agrees with Newton's first law?
• Step 1: Newton's first law: an object keeps moving at constant velocity unless a resultant force acts.
• Step 2: So the answer is: Student 2
• Answer: Student 2
• Pause after each step and ask a student to say what comes next.

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

1. Peer review means… (the result can never be questioned / the scientist checks their own work only / other scientists check work before it is published / friends vote on the result) → other scientists check work before it is publishedPrompt: "Peers" are other experts in the same field.
2. Two scientists explain why some lakes have fewer fish than ten years ago. Scientist 1: Farm fertiliser washed into the lakes caused algae to grow; when the algae died, bacteria used up the oxygen in the water. Scientist 2: Warmer water from climate change holds less dissolved oxygen, so fewer fish survive. What do both scientists agree on? (Low oxygen in the water harms the fish. / Fish numbers have increased. / Fertiliser is the only cause. / The water is getting colder.) → Low oxygen in the water harms the fish.Prompt: Read each viewpoint and underline its key claim.

• 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.

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

1. Two students explain why a metal spoon in hot soup feels hotter than a wooden spoon in the same soup. Student 1: The metal spoon is at a higher temperature than the wooden spoon. Student 2: Both spoons reach a similar temperature at the end in the soup, but metal conducts thermal energy into your hand much faster, so it feels hotter. Which student's explanation depends on how fast energy is transferred? (Neither student / Student 1 / Student 2 / Both students) → Student 2Prompt: Read each viewpoint and underline its key claim.
2. Peer review means… (friends vote on the result / other scientists check work before it is published / the scientist checks their own work only / the result can never be questioned) → other scientists check work before it is publishedPrompt: "Peers" are other experts in the same field.

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-11.