Chief Examiner's report

Background and availability

After they have finished their marking all examiners write a report on the scripts they have seen. Once the Grade Award Meeting is over the Principal Examiner for each component writes a report based on their own and their assistant examiners’ observations. The Chief Examiner then compiles the overall subject report and this is published in October following the May examination session (or April following the November examination session). If you are a new teacher or if your students performed less well than you expected it is well worth you reading this report carefully. Even experienced teachers can still learn a lot, particularly every time there is a change in the programme (as there were for the examinations taken in May 2009 and in May 2016). Following the May session there are actually two reports, one for Time Zone 1 (TZ1) and one for Time Zone 2 (TZ2). The IA component is the same in both reports but everything else is different. There is a completely separate report that covers Extended Essays in Chemistry.

The reports are available in the programme resources section of My IB and can be read online or can be downloaded from there as a pdf file.

Basic information

Outline

The report follows a fairly fixed outline each year. It starts by giving the overall grade boundaries. That is the overall percentage mark a student must achieve to gain a particular grade. (The boundaries for May 2017 TZ2 and TZ1 are given at the foot of the page on grade boundaries). The report then looks in detail at Internal Assessment and follows this by looking in detail at the three examination papers at both HL and SL.

Internal Assessment

This is the same for both SL and HL. It gives the component grade boundaries and then looks first at the range and suitability of the work submitted and then the candidates’ performance against each criterion. The next two sections on Internal Assessment are both particularly helpful to teachers. First comes the recommendations for teaching future candidates and then the instructions that were issued to moderators. Recommendations for teaching future candidates tend to include many obvious statements such as candidates should be made aware of the criteria by which they are being assessed. It also contains some recommendations that are perhaps not quite so obvious such as candidates need to consider repeat trials, calibration or generation of sufficient data to undertake graphical analysis where possible.

These points and of course many more are given in this website on the section on Internal Assessment. By reading through all these recommendations and by reading the instructions to moderators you should be able to ensure that your students gain a high mark for IA and that the marks you award are not heavily moderated down.

After covering the Internal Assessment the report then looks first at the three Higher Level Papers and then the three Standard Level Papers.

Paper 1

For HL and SL Paper 1 the report first lists the component grade boundaries then gives general comments followed by the strengths and weaknesses of candidates in their treatment of individual questions. In the general comments it gives information from the G2s such as 98% thought that the level of difficulty was appropriate and 2% considered the paper too difficult. Syllabus coverage was considered satisfactory by 36% and good by 64% etc.

Perhaps the most useful information is given under the next heading when comments are given against many of the individual questions. For example, one year in the HL May TZ1 Exam Question 20 was eliminated. The reason given was “The question contained the phrase ‘according to the collision theory’ which resulted in possible ambiguous answers. The question in fact had a negative discrimination index of -0.02 indicating that the question confused even the more able candidates.” It is also useful to see the response to teachers’ comments on the Teacher Feedback forms. For example from the same examination paper:

 “Question 10. Two respondents stated that lattice descriptions such as cubic, face-centred cubic or body-centred cubic are not required. According to AS 4.1.8 (this was from the old syllabus), it is stated that candidates should be able to describe the lattice structure of ionic compounds and in the corresponding teachers note the example of sodium chloride is cited. Therefore candidates should know that sodium chloride has a cubic type lattice. More complicated lattices such as face-centred cubic etc. are not required and are not mentioned in this question and hence the question as written is perfectly valid.”

 This sort of information can clearly help you when you teach students in the future.

Papers 2 and 3

These follow a similar format both for HL and for SL. After giving the component grade boundaries and general comments the report details those areas of the programme and examination that appeared difficult to the candidates and follows this by a list of those areas where candidates appeared well-prepared.

For example, the areas of difficulty listed for the TZ2 SL May 2017 Paper 2 listed the following twelve points:

  • Identifying problems in a practical procedure and suggesting solutions
  • Relating chemical models to the critical observations underpinning them
  • Combining redox half-equations
  • Handling uncertainties
  • Inferring chemical equations and deducing factors disturbing an equilibrium
  • Clearly differentiating between intermolecular and intramolecular interactions
  • Resonance structures
  • Applying generalized concepts to particular situations.
  • Equations for acid deposition from nitrogen oxides
  • Deducing the monomer from the structure of an addition polymer
  • Carrying out titration calculations
  • Recognizing that fragments in a mass spectrometer have a positive charge

The report then goes on to detail any specific problems that were identified in each of the questions on the paper. 

By looking at the list of areas of difficulty and the problems students experienced with individual questions and by using the information given on this site under Areas of difficulty you should be able to help students avoid some of the obvious pitfalls and thus increase their chances of performing well.

The report ends for each Paper by giving recommendations and guidance for the teaching of future candidates.

For example, the following recommendations were given for SL Paper 2 in the TZ2 May 2017 examination:

  1. Training candidates to read the question carefully with regard to what exactly it is asking, the command term used (and the implications of this, taking into account the number of marks available) as well as any specification of the units or precision of the answer. When comparing things, reference should be made to both. If a question is about to a particular substance or reaction, then the answer should specifically refer to it.
  2. Practicing writing answers to questions frequently asked so as to avoid makingmistakes, particularly with regard to the precise use of language, that have previously been problems.
  3. Note that the Nature of Science sections of the syllabus are examinable.
  4. Encourage students to write out the method of their calculation as this may enable the examiner to award partial credit for incorrect answers. Rounding should only be carried out at the end otherwise it can lead to significant errors.
  5. Carry out more exercises in which candidates are required to deal with experimental uncertainties or reflect on weaknesses in practical techniques.
  6. Ensure candidates know what kind of bonding is likely to be present in a givencompound and, for molecular substances, that they clearly discriminate betweenintramolecular and intermolecular interactions, and when these are broken.

All these points and more have already been emphasised on previous pages in this section on examinations e.g. Advice to students.

Summary

These reports appear after every examination session and by reading them carefully you can get a good picture of what students find difficult and it can help you very much as you prepare students in future years.

All materials on this website are for the exclusive use of teachers and students at subscribing schools for the period of their subscription. Any unauthorised copying or posting of materials on other websites is an infringement of our copyright and could result in your account being blocked and legal action being taken against you.