KEY INFO

• Accuracy

  Accuracy is how close a measured value is to its true value
• Reliability

  Reliability refers to the ability of an experiment to produce consistent results
• Validity

  Validity is how appropriate an experimental method is at achieving the aim of an experiment
• Increasing the reliability of an experiment can virtually always be done by repeating an experiment, collecting values, and calculating the average of the values.
• Tips for answering practical questions

  • Identify the independent variable (the thing you change)
  • Identify the dependent variable (the thing that changes as a result)
  • Identify the control variables (things you keep the same)
  • State the equipment used for each measurement
  • Discuss safety precautions like using goggles, gloves, etc.
  • Discuss the accuracy of measurements and how to reduce errors/uncertainties
  • Discuss taking multiple/repeat measurements to calculate a mean