Required Practical Skills

• What is the definition of accuracy in measurements?

  A measured result that is close to the true value.
• What does calibration refer to in measurement?

  Marking a scale on a measuring instrument.
• What is data?

  Qualitative or quantitative information that has been collected.
• How is evidence defined in scientific terms?

  Data which can be used to support a hypothesis.
• What constitutes a fair test in an experiment?

  A test in which the only independent variable has been allowed to affect the dependent variable.
• What is a hypothesis?

  A proposal intended to explain certain facts or observations.
• What does the term interval refer to in measurements?

  The quantity between readings, e.g., a set of 5 readings equally spaced over a distance.
• What is a prediction in scientific terms?

  An intelligent guess based on some knowledge.
• What is measurement error?

  The difference between a measured value and the true value.
• What are anomalies in a set of results?

  Values that differ from the expected and variation caused by random uncertainty.
• What is random error in measurements?

  Causes a reading to be spread about the true value due to unpredictable variations.
• How can the effect of random error be reduced?

  By making more measurements and calculating a new mean.
• What is systematic error?

  Readings that differ from the true value by a consistent amount each time a measurement is made.
• What should be done if a systematic error is suspected?

  The data collection should be repeated using a different technique or equipment.
• What is zero error?

  When a measuring system gives a false reading when the measured quantity is zero.
• What often serves as the starting point of an investigation?

  Observations.
• What is an independent variable in an investigation?

  The variable that is actively changed.
• What is a dependent variable?

  The variable that depends on the independent variable.
• What is a control variable?

  The variable that is kept the same during the investigation.
• What is a categoric variable?

  A variable described by a label (qualitative data).
• What is a continuous variable?

  A measured variable with a numerical value (quantitative data).
• What are the key steps to ensure a fair test in an investigation?

  • Keep control variables the same.
  • Set up control groups for comparisons.
  • Ensure only the independent variable is tested.
• What should be included in a risk assessment for an investigation?

  • Identify potential hazards.
  • Determine necessary safety precautions.
  • Ensure the investigation is safe to carry out.
• What are the important considerations when designing an investigation?

  • Choose the best values for variables.
  • Select a suitable range for the independent variable.
  • Obtain accurate and precise data.
• What is the purpose of tables in presenting data?

  To record results from experiments with titles and headings.
• When should bar charts be used in data presentation?

  When you have categoric variables.
• When should line graphs be used in data presentation?

  When the data is continuous.
• What should be done when drawing graphs?

  Use a sensible scale and label both axes.
• What is the purpose of a line of best fit in a line graph?

  To represent the trend of the data accurately.
• What should be done when creating a bar chart?

  Label each bar.