'Scaffolding' the investigation

'Scaffolding' the Individual Scientific Investigation

Some schools may find the time to do two investigations and then choose the best one. However the programme only really allows for one ten-hour slot so the majority of students will only do their Individual Scientific Investigation once and therefore it is crucial to prepare them thoroughly beforehand. This can be done by scaffolding, i.e. introducing and familiarising them in the skills needed during their first year so that when they start the actual investigation they are already fully prepared.

One of the best ways to do this is through the experiments that cover the mandatory areas and also through other practicals that provide training or exposure to those skills not covered elsewhere. I have provided questions at the end of each practical to test the students understanding. Remember that apart from the Individual Scientific Investigation, the IB does not require you to mark any of the experiments carried out in the practical scheme of work including the ones covering the mandatory areas. However, in certain experiments it may well be worth you marking specific parts to check that they are acquiring and applying the skills learned correctly. For example, in the experiments to determine Enthalpy changes and Determining Ea for a reaction, can students construct the appropriate graphs? In the enthalpy experiment are they then able to extrapolate correctly to compensate for heat loss and in the Ea experiment are they able to measure and use the gradient?

Skills required

So what skills are required? A good way to approach this is to look at the five different assessment criteria and extract what students need to achieve to attain high marks. Remember too that many of these skills will also be required for their Extended Essay (even if it is not in Chemistry) and later when they continue their studies at university or other forms of higher education. The IB is about life-long learning!

General skills including communication

  • Accurate and careful note taking
  • Essay or extended laboratory report writing
  • Consistent use of accurate and scientific terminology (i.e. IUPAC and SI units)
  • Academic honesty, use of citations and referencing sources

Personal engagement and exploration

  • Research skills (library, Internet, journals etc.)
  • Awareness and adherence to Health and Safety considerations (risk assessment)
  • IB ethical experimentation policy
  • Stating a sharply focused research question
  • Choice of appropriate apparatus/secondary sources together with associated uncertainties
  • Identification and use of independent, dependent and controlled variables
  • The collection of relevant, reliable and sufficient data

Analysis and interpretation

  • Correct use of labels, units and decimal points applied to tables of data
  • Estimation of total uncertainties in measurements
  • Setting out the data processing in a logical coherent way
  • Use of conventions in graph plotting
  • Accurate and appropriate analysis
  • Justifying a trend or hypothesis from analysed data

Conclusion and evaluation

  • Explaining a trend using underlying scientific concepts
  • Considering the impact of total uncertainty in measurements
  • Relating a trend or experimental result to the research question
  • Identifying limitations in recorded data
  • Identifying limitations of the method and apparatus
  • Suggesting realistic improvements

What is worth noting is that virtually all these skills apply irrespective of whether the student designs and carries out their own practical work or relies on secondary data obtained from elsewhere. The only two exceptions are the choice of suitable apparatus and awareness of Health and Safety considerations.

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