Lesson at a Glance | He Tirohanga Whakamua
Ngā Whāinga Ako | Learning Intentions
Students will know
- That Level 1 Science requires specifying an Independent Variable (IV) with a range of at least 5 values with appropriate units.
- How to define a Dependent Variable (DV) including the exact measurement technique and units (e.g., bubbles per 2 minutes, mm length change).
- How controlling at least 3 key controlled variables (CVs) establishes experimental validity.
Students will demonstrate
- By completing a detailed Variables Specification Table.
- By completing Section 3 of their Level 1 Science Biological Investigation Logbook.
Curriculum alignment
- NZC (2007) · Science · Level 6 · Nature of Science: “Show an increasing awareness of the complexity of working scientifically, including recognition of multiple variables.”
Do Now | Tīmatanga Whakaaro (10 min)
Common Assessor Error Prompt:
"A student writes: 'My IV is lamp distance. I controlled lamp distance at 10cm.' What is wrong with this statement?"
Unpack: The Independent Variable is what you deliberately change. It cannot be kept constant! If distance is your IV, your controlled variables must be OTHER factors that could affect photosynthesis, such as water temperature, sodium bicarbonate concentration, or plant sprig length.
The 3 Variable Categories for Level 1 Science (15 min)
1. Independent Variable (IV)
Must have at least 5 values across a logical range with units (e.g. Lamp Distance: 10cm, 20cm, 30cm, 40cm, 50cm; or Temperature: 10°C, 20°C, 30°C, 40°C, 50°C).
2. Dependent Variable (DV)
What you measure to gauge biological activity. Specify units and time period (e.g. number of O₂ bubbles released per 2 minutes, or mass change in grams).
3. Controlled Variables (CVs)
Identify at least 3 factors to keep constant, specify EXACTLY HOW you will keep them constant, and explain WHY failing to do so invalidates data.
📁 Biological Investigation Logbook — Section 3: Variables & Control Plan
Students open their Level 1 Science Logbook and complete Section 3:
Section 3 Requirements:
1. Independent Variable (IV): Name IV, units, and list 5 distinct levels (e.g. 5cm, 10cm, 15cm, 20cm, 25cm).
2. Dependent Variable (DV): Name DV, measurement tool, time interval, and units.
3. Controlled Variables Table: List 3 CVs, state the exact control method for each, and explain the biological consequence if left uncontrolled.
Exit Verification | Ka Mutu Hoki (5 min)
Exit Check:
"My Section 3 contains 5 explicit IV values and a 3-row controlled variables matrix with control methods."
Teacher Planning & NCEA Alignment
NCEA Level 1 Science Alignment (4 Credits):
- Variables: Specify the independent variable with a range of at least 5 values, a dependent variable with units, and key controlled variables.
- Validity: Demonstrate understanding of how controlling extraneous variables ensures valid results.
Vocabulary: Independent variable, dependent variable, controlled variable, experimental validity, IV range, measurement precision.
Other teaching approach: Guided Viewing & Practical Investigation →