How is ESS Assessed?
On this page we provide an overview of assessment from May 2026 for ESS. There are many similarities with previous forms of assessment but also some significant changes, especially for HL.This information is based on an analysis of the specimen exams and published assessment overviews by the IB.
In both SL and HL there are three assessed components.
Internal Assessment is an independent investigation of a student developed research question. You can read more about the IA in this section: Independent Investigation from 2024. At SL it contributes 25% to the final grade and at HL 20% to the final grade.
Paper 1 consists of a Resource Booklet which is a previously unseen case study focused on one location, for example in November 2017 the location was Iceland and the main themes were Energy and Fisheries. There is almost always a strong emphasis on the ecological interactions in that system. This is accompanied by a Question Booklet that has questions based on the Resource Booklet but requires students to apply their learning, both of practical and knowledge to the case study. Students must answer all questions.
Paper 2 consists of two sections, A and B.
Section A consists of short-answer and data-based questions following prompts that may be graphics or data tables. Students must answer all questions.
Section B contains structured essay questions. Each question is worth 20 marks and consists of part a worth 4 marks, part b worth 7 marks and part c worth 9 marks. Parts a and b are marked against marking points, like paper 1 and section A, part c is marked against markbands.
Both papers 1 and 2 require the use of calculators.
Both papers will receive 5 minutes of reading time where students can look through the papers but not write anything.
Students need to know formulae from the course. They are not provided.
| SL | HL | |
|---|---|---|
| Duration | 1 hour | 2 hours |
| Marks | 35 | 70 |
| Weighting | 25% | 30% |
SL
The SL Resource Booklet (RB) and Question Booklet (QB) are very similar to the previous versions of this assessment. Students are asked to decribe and outline data. There is a mixture of 1, 2, 3 and 4 mark questions with one final 6 mark question which asks students to apply all or most of the information in the RB to a holistic question assessing the sustainability or conservation or a particular aspect of the location in question.
Practice will previous Paper 1s will replicate the experience of this examination to a large extent.
HL
The HL RB contains about four sides more information than the SL booklet (15 pages vs 11 pages in the specimen papers). The QB contains twice the number of marks as the SL paper. There is a mixture of 1, 2, 3 and 4 mark questions with three 6 mark question which ask students to apply their knowledge to 3 sections of the RB. These questions are less holistic than the SL question as they focus on one aspect of the case study and are intersperced in the QB.
There is more demand to apply knowledge to data, there is greater coverage of the topics than at SL and HL content is included.
Teacher only boxPractice with previous Paper 1s will allow a shorter experience of the final examination and they will need adapting to provide an authentic replication of the final exam before more exam papers are available.
| SL | HL | |
|---|---|---|
| Duration | 2 hours | 2.5 hours |
| Total Marks | 60 | 80 |
| Weighting | 50% | 50% |
| Section A | 40 | 40 |
| Section B | 20 One structured essay from a choice of two. | 40 Two structured essays from a choice of three |
SL and HL
Section A has increased from 25 marks in the previous assessment model to 40 marks.
There are questions worth, 1, 2, 3, 4 and 5 marks. In the specimen papers there are two five mark questions with command terms, "explain" "to what extent" and "discuss". These are still marked against marking points and students should focus on offering pros/cons, positive/negative, strengths/weaknesses and a conclusion for the command terms which require this, e.g. "discuss".
In both papers, graphs and tables may provide descriptive statistical data such as means and standard errors. Students need to be able to interpret this information.
SL
Section B has decreased from two structured essays from a choice of four in the previous assessment model to one structured essay from a choice of two.
HL
Some of the questions are the same as the SL paper but HL content is included as well.
Section B requires two structured essays and these are likely to include content from the HL lenses and their application to the part of the course.
Teacher only boxPrevious section A questions will be useful as practice and will allow a shorter practice for the final examination but they will need adapting to add in 5 mark questions and analysis of graphs with statistics for a more complete experience.
The Section B questions at HL will need to include the HL lenses and HL content for a more authentic practice until there more final exam papers are available.