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independent variable
Colour is deliberately changed.
Class 8 · English Medium · Pearson Edexcel · General science
Pearson Lower Secondary Science qualification specification, Issue 2 November 2024 · Chapter companion part
Year 8 · Planning fair tests and recognising risks
Build Year 8 enquiry skills: planning fair tests and recognising risks, using supplied data and your own reasoning.
Original Year 8 practice for shared Pearson Year 7–9 scientific enquiry objectives. The Class 8 Edexcel course slot provides access; confirm programme-year placement with a teacher. This is selected companion practice, not full national, Cambridge or Pearson programme coverage.
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Learn the idea
A method explains how evidence will be obtained: what changes, what is measured, what stays alike and how observations are recorded. Select equipment for the quantity and useful measurement range, rather than because it looks scientific. Online practice can use the supplied simulation data without handling equipment.
Name the variables
The independent variable is the factor deliberately changed in this simple test. The dependent variable is the measured outcome. Controlled variables are other relevant conditions kept alike. Changing one factor at a time helps this comparison, but not every kind of scientific investigation is a one-factor experiment.
Repeats and unusual results
Repeated measurements help reveal how much results vary. An anomalous result is one that stands apart from the other results or pattern; it is a reason to inspect the method and consider more evidence. Keep it in the original record. Do not erase it just to make a prediction or graph look better.
Hazard and risk are different
A hazard is something with the potential to cause harm. Risk concerns how likely harm is and how serious it could be in the actual situation. Acute toxicity means harm from short exposure; irritant materials can irritate skin, eyes or airways as described by their labels. Recognise the five study pictograms, read the full label and follow teacher instructions; a missing icon does not prove a material safe.
Plan a matched virtual comparison
For a surface-colour investigation, use virtual surfaces with the same material, area, thickness, starting temperature, exposure and duration. Colour is the input; temperature rise is the response. Measure rise as final minus initial temperature. If both colour and material differ, the simple comparison cannot isolate colour.
Inspect variation before deciding
Supplied rises for one setting are 5, 6 and 5 °C; another set contains 5, 6 and 15 °C. The 15 °C result needs checking but must remain in the original record. Inspect exposure, timing, sensor placement and transcription, then consider further supplied repeats. Similar repeated readings can still share a method problem.
Evaluate controls against actual hazards
A corrosive symbol may indicate severe skin/eye damage or metal attack; a flame indicates flammability; skull/crossbones indicates serious acute toxicity. Exclamation and tree/fish symbols have different meanings. A teacher chooses controls from the actual material and activity. Eye protection, ventilation and distance each address particular exposure routes; none is a blanket guarantee.
Use safe alternatives and suitable tools
Here all temperature and hazard information is supplied. No flame, chemical or hot-surface trial is needed. In a real teacher-led lab, instrument range, suitable supports, eye protection and appropriate fume control are selected for the actual task; do not improvise a burner procedure from a web lesson. A simulation can preserve the enquiry question while removing exposure.
Worked example
The virtual surfaces start at 20 °C and finish at 25 °C and 28 °C after equal exposure. Their rises are 5 and 8 °C, a 3 °C difference in rise. To investigate colour, relevant material and exposure conditions must be comparable.
- Identify the question, variables and supplied evidence.
- Show calculations with units and distinguish readings from estimates.
- Explain the conclusion, then name a limitation and a useful next step.
Common mistake
A dependent variable is the response being measured; a control condition is held comparable.
A tool limitation
Automatic timing can improve consistency, but it does not prove a sensor is correctly placed or checked.
A risk comparison
Removing heating from an online task addresses burn/fire exposure more directly than claiming one item of protective equipment makes all setups safe.
Your written practice
Show your working on paper and enter your answer here. If it does not match, compare the model and try again.
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dependent variable
Temperature rise is the measured response.
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controlled variables
They are relevant conditions held comparable.
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thermometer
The instrument and its range must suit the temperature task.
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anomalous result
It is a result to inspect and retain in the original record.
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corrosive
The corrosion warning concerns severe burns or metal attack.
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environmental harm
It especially alerts learners to aquatic-environment hazards.
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8
28 − 20 = 8 °C rise in the supplied model.
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3
8 − 5 = 3 °C; the comparison still depends on matched conditions.
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Change colour while holding material, dimensions, exposure, duration and starting temperature comparable; record initial/final values and repeat the setting.
State input, response, controls, calculation and recording plan.
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Both colour and material differ, so a temperature-rise difference cannot be assigned to colour alone.
Name the confounded factors and a matched comparison.
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Inspect timing, exposure, sensor placement, the original record and any recorded incident; gather further supplied repeats where useful.
Keep the value visible and explain any later decision about its use.
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All repeats may share the same mismatch or instrument problem; closeness alone does not inspect the comparison design.
Separate repeat variation from control of other influences.
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The skull/crossbones indicates serious acute toxicity; the exclamation mark can indicate irritant/harmful effects. The complete label is needed for the actual material.
Explain the distinction and the limits of icon-only decisions.
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Goggles address particular eye risks but do not control every burn, fire or inhalation risk; a teacher-approved assessment and method are still needed.
Link controls to actual exposure routes; use supplied data here.
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Use the supplied temperature series, a virtual comparison and a written risk assessment of a pictured school setup.
Keep the scientific question and remove real heat or chemical handling.
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Rise is final minus initial; different starting values can produce different rises even with the same final value.
Identify the needed starting measurement and comparable conditions.
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It can record at consistent time intervals, but a badly placed or offset sensor can still give misleading values.
Technology should address a named problem, not replace method checks.
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Equal exposure is a condition controlled for comparison; removing real heating is a safety control that removes exposure to harm.
Keep fair-comparison conditions and risk measures distinct.
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Retain each supplied reading, inspect unusual values and compare further supplied repeats; use diagrams rather than actual hazardous equipment.
Obtain useful evidence without creating exposure or hiding disagreement.
Enquiry notebook challenge
Design a matched virtual surface test, critique a mismatched comparison and annotate a pictured risk assessment using the five study icons.
Review with a guardian or teacher
- Calculate and compare temperature rises rather than unrelated final readings.
- Inspect controls, repeats and instrument suitability.
- Link each hazard/exposure to a teacher-approved control or supplied-data alternative.
Keep your work on paper or in a local file. This page does not upload it or automatically grade the project.
Curriculum companion and further study
This original Kidemy practice is mapped to selected Year 8 objectives in the Pearson Lower Secondary Science qualification specification, Issue 2 November 2024, PDF page 44. This public source does not establish the full programme or a complete textbook chapter list.
Pearson qualification specification and source →
Continue with your teacher and programme materials
- Apply the enquiry skills to further biology, chemistry and physics contexts with a teacher.
- Independent practical assessment and the wider programme objectives remain; supplied model data do not establish hands-on competence.
Teacher-led lessons, schedules and prices for this outline are upcoming. You can use any starter practice above now without booking.
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