October 2010

Assessment criteria for IGCSE practical assessments
The skills assessed are C1 to C4.
C1: Using and organising techniques, apparatus and materials
C2: Observing, measuring and recording
C3: Handling experimental observations and data.
C4: Planning, carrying out and evaluating investigations

Each skill is assessed on a six point scale. Level six is the highest level of achievement.
Notice that although the scale has six points descriptions are only given for 2, 4 and 6. A grade in between may be given if the work falls between two levels.

2- Simple one stage instructions for an experiment can be followed. If many instructions for an experiment are given some of it can be followed but help may be given to complete the task. The instructions may be written, oral or from a diagram. The apparatus and materials are used properly however some reminders may be given on safety.
4- Can follow the instructions for an experiment with many stages without help. The apparatus is used properly with no reminders on safety.
6- Can follow the instructions for an experiment with many stages without help and can modify or adjust one step in order to complete the task. The adjustment must be taken as a result of the previous instructions. The apparatus is used properly with no reminders on safety.

2- Can make observations or take readings in an experiment when help is given. The data obtained can be recorded in a table when the table is provided in a full form including headings and units.
4-Can make observations and readings in an experiment with only a brief outline of what is expected. The observations can be made without help but accuracy may be lacking. The results can be recorded in a table when the headings only are given.
6- Makes good observations and measurements that are accurate. For example readings repeated, good detail included etc. The results are recorded accurately in a table and no help is given in the set up of the table.

2- The results in an experiment are processed e.g. calculations carried out, graphs plotted but detailed help is needed or if no help is given the results are incompletely processed. A simple conclusion is drawn from the experiment.
4- The results in an experiment are processed and only very brief and partial help is given. e.g. the student is told the axis to use in the graph.
The graph may be plotted without help but there are some inaccuracies.
A conclusion is drawn from the experiment which is consistent with the results. The patterns in the results are noted.
6- The results are processed correctly without any assistance.
Anomalous results are noticed and commented upon. The sources of experimental error are noted and commented upon. The conclusions are written in a way that recognises trends and relationships.

2 – An experiment is planned and carried out but the variables may not be fully controlled or measured. The method is adjusted but with no real direction.
4-An experiment with more than one stage is planned and carried out.
Most of the variables will be controlled or measured. The original plan is commented upon critically and changes may be carried out in the method that is relevant and positive.
6- A logical experimental plan is produced and carried out. In the experiment there will be more than one variable to be controlled or measured. The procedure is fully evaluated and improvements are suggested. The method may be modified during the experimental work and this is fully justified. Unexpected results are dealt with e.g. left out of a line of best fit etc.

Skills assessed
C1: Using & organizing techniques, apparatus and materials
C2: Observing, measuring & recording
C3: Interpreting & evaluating experimental observations and data

Aftershave lotions are used to cool the skin after shaving. You are going to make your own aftershave and compare it with some commercial aftershaves. In the experiment you are going to investigate which aftershave produces the greatest cooling effect.

1. Make your own aftershave lotion to test. You need to mix together 8cm 3 of alcohol, 1cm 3 of glycerol and 4cm 3 of water in a boiling tube. Stopper the tube and shake to mix the ingredients properly.
2. Attach a small amount of cotton wool to a thermometer bulb using a rubber band.
3. Record the temperature reading on the thermometer
4. Now dip the cotton wool covered end of the thermometer into one of the lotions.
5. Remove the thermometer and place the wet end on a white tile.
6. Record the temperature at regular intervals for a suitable time period. You will need enough results to plot a graph for each lotion investigated.
7. Repeat with each of the lotions provided you can also try water as a comparison. Try to make your tests as fair as possible.