Designing Experiments

Lesson Overview

Unit: Exploring the Wonders of Science (20 lessons)
Lesson Number: 3 of 20
Duration: 60 minutes
Class Size: 1 student (1:1 setting)
Age Group: Year 11 (15-16 years old)
National Curriculum Reference:

• Scientific enquiry (Working scientifically)
• Programme of Study: Key Stage 4 Science
• National Curriculum 2014 for England

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Learning Objectives

By the end of this lesson, the student will be able to:

1. Formulate a clear scientific hypothesis based on a question of personal scientific interest.
2. Identify and categorise variables: independent, dependent, and control variables within an experimental design.
3. Develop a simple, feasible method for carrying out the experiment, ensuring it is safe, ethical, and controlled.
4. Understand the importance of controls and repetitions in scientific experiments to ensure valid and reliable results.

Aligned National Curriculum reference:

• Working scientifically: "Plan different types of scientific enquiries to answer questions, including recognising and controlling variables where necessary."
• Working scientifically: "Use appropriate techniques, apparatus, and materials during fieldwork and laboratory work, paying attention to health and safety."
• Working scientifically: "Recognise the importance of repetition and sometimes randomisation in investigations and explain how both help to improve the reliability of results."

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Success Criteria

By the end of this lesson, the student can demonstrate:

• A clearly written hypothesis directly related to their chosen scientific question.
• Accurate identification of at least one independent variable, one dependent variable, and control variables.
• A step-by-step experimental method that is logical, manageable within available resources, and includes safety considerations.
• An explanation of why variables need to be controlled and how repetition strengthens conclusions.
• Submission of their full experimental design that meets all above criteria.

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Resources Required

• Science notebook or worksheet for experimental design
• Pens/pencils
• Whiteboard and marker (if available, for discussion prompts)
• Reference materials on variable types (handouts or textbook excerpts)
• Example scenarios of basic experiments (e.g., effect of light on plant growth)
• Timer or stopwatch (if applicable for practical follow-up)

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Lesson Structure

1. Starter Activity (10 minutes)

Objective: Engage the student and activate prior knowledge about experiments and variables.

• Begin with a quick discussion: “Can you think of a question about the world around you that we could test scientifically?”
• Introduce or recap key terms: hypothesis, independent variable, dependent variable, control variables.
• Show 2-3 simple experiment examples (e.g., effect of temperature on yeast growth) and identify variables together.
• Success criteria reminder: student should feel confident to create a hypothesis and spot variables.

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2. Main Teaching & Modelling (15 minutes)

Objective: Teacher models how to design an experiment by choosing a sample question.

• Choose a relatable scientific question (e.g., "Does the amount of sunlight affect the temperature of a surface?").
• Write a hypothesis aloud, explaining the reasoning.
• List the variables: Independent (amount of sunlight), dependent (temperature), controls (type of surface, time of day).
• Draft a simple method step-by-step (including equipment, safety considerations).
• Emphasise controlling variables and why repetition is essential for reliable results.
• Use questioning strategies to engage the student (e.g., “Why do you think control variables matter here?”).

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3. Student Activity: Design an Experiment (25 minutes)

• Student selects their own question of interest to investigate (teacher to scaffold or suggest if required).
• Student writes their hypothesis clearly in their notebook or worksheet.
• Student identifies variables, labelling them as independent, dependent, or control.
• Student plans a step-by-step method including:
  • Materials needed
  • Procedure (clear enough to be followed by others)
  • Safety considerations
  • Number of repetitions or trials
• The teacher circulates, asking probing questions and offering support to deepen thinking and ensure alignment with the success criteria.

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4. Review and Reflect (10 minutes)

Objective: Assess understanding and consolidate learning.

• Student reads their experimental design aloud to teacher.
• Teacher uses success criteria checklist to provide feedback:
  • Is the hypothesis clear and testable?
  • Are variables correctly identified?
  • Is the method logical and controlled?
  • Has the student considered safety and repetition?
• Teacher encourages student to reflect on how controlling variables and repetition improve experimental reliability.
• Identify one thing the student feels confident about and one area to improve before the next lesson.

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Assessment

• Formative assessment through questioning during modelling and student activity.
• Summative assessment via submission of the experimental design document meeting all success criteria.
• Teacher feedback targets specific components: hypothesis clarity, variable identification, and method detail.

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Differentiation & Personalisation

• Since the class is 1:1, personalise the question choice and level of scaffolding based on the student's confidence and prior knowledge.
• Provide extra scaffolding prompts or visual organisers for variable categorisation if needed.
• Challenge more able students by encouraging them to include independent variables with multiple levels or suggest how to improve reliability through randomisation.

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Extension Ideas (linked to future lessons)

• Prepare to conduct the designed experiment in later lessons.
• Introduce data collection techniques and how to record results systematically.
• Explore how to analyse data statistically in subsequent lessons.

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Health & Safety Considerations

• Ensure the experiment design is safe (e.g., no hazardous chemicals unless supervised, no unsafe materials).
• Discuss safety with student prior to experimentation.
• All equipment and materials must be handled according to school guidelines.

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This lesson plan integrates National Curriculum requirements and actively develops the skill of planning scientific enquiries—a vital competence for GCSE and beyond.