5. Marking toolkit

Chemistry

Note

The assessment criteria were covered in section 2.

Recall that there are a total of four criteria, each worth six marks with a total of 24 marks.
Each criterion is composed of descriptors that correspond to different achievement levels and a range of marks.
Teachers must mark the scientific investigation against the criteria utilising the level descriptors.

Note

The assessment criteria are the same for SL and HL.

When marking the report, teachers should aim to find the level descriptor that corresponds to the level reached by the student, using what is known as the best-fit model.
This model means that marks should be awarded when the students work matches different aspects of a particular criterion at different levels.
Therefore, the mark given a particular criterion should reflect the balance of the achievement against that criterion.

Example

Take, for example, a piece of work that satisfies the following level descriptors.

For the first and third strands the teacher awards the highest level descriptors and for the second stand, the second highest descriptor.
Using the best-fit model, the teacher might decide to award the student 5 marks for this criterion.

Teachers should mark positively; this means awarding credit for what the student has done instead of penalizing for what they haven't done or should have done.
Only whole numbers should be used when awarding marks; decimals or fractions should not be used.
It is recommended that teachers read the completed report once to get a feel for the work before awarding any marks.
Teachers must utilise a best-fit approach when awarding marks for each criterion. Averages calculated from the different strands are not appropriate.
When marking the report, the level descriptors for each criterion should be read (starting with the lowest level) until the descriptor that matches the level of the work is reached.
If the work seems to be between two descriptors, both descriptors should be read once more and the descriptor that better matches the work should be chosen.
Where there are two marks with a level, teachers should decide if the work satisfies the descriptor to a greater extent or a lesser extent. If the former applies, the teacher should apply the higher mark, if the latter applies, the lower mark should be awarded.
Teachers should consider how the command terms have been addressed in the report when deciding on the level of the work.
Depending on the structure of the report, evidence for a single criterion may appear in more than one section.

Note

It is not a requirement that students address the criteria in a linear fashion.

The highest level descriptors do not imply that the work is perfect. It is not a requirement that the work must satisfy every single aspect of a level descriptor for that mark to be awarded.
It is possible for a student to be awarded high marks in one criterion and low marks in another. Teachers should not assume that a student's work must be awarded high marks in all criteria or low marks.
The assessment criteria should be made available to students throughout the process.
A mark of zero can be awarded if there is no evidence for the level descriptors in a criterion. If some evidence exists, a zero should be awarded only if the work is completely irrelevant to the descriptors.
If one strand is awarded a zero and the other strands within the criterion are not, the overall mark for the criterion should take into account the students achievement in the non-zero strands and not overly-penalize the zero strand.

Internal Standardization and External Moderation

Internal standardization involves the standardization of marks within the school.
This is usually done when there is more than one teacher responsible for the cohort.
This can result in more consistent marking when done correctly.
External moderation occurs after the marks have entered on IBIS.
A list of reports is automatically selected and teachers must upload the annotated student work.
The annotations and comments should justify the marks awarded for the report.

Note

Any work submitted to the IB must be authenticated before it is submitted.

Internal Assessment

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Chemistry

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