Internal assessment is an integral part of the course and is compulsory for both standard level (SL) and higher level (HL) students.
It enables students to demonstrate the application of their skills and knowledge and to pursue their personal interests, without the time limitations and other constraints associated with written examinations.
The internal assessment should, as far as possible, be woven into normal classroom teaching and not be a separate activity conducted after a course has been taught.
Note
The internal assessment requirements at SL and at HL are the same.
The internal assessment (IA), worth 20% for HL and 25% for SL, involves a written report investigating a specific ESS issue and applying the results to a broader context.
Note
The IA report should be between 1500 and 3000 words, excluding bibliography and data.
Criterion
Number of available marks
A: Research question and inquiry
4 marks
B: Strategy
4 marks
C: Method
4 marks
D: Treatment of data
6 marks
E: Analysis and conclusion
6 marks
F: Evaluation
6 marks
Total
30 marks
A total of 10 hours is allocated for the scientific investigation.
This time encompasses an explanation of the task requirements
Time for students to collect data (either through laboratory work or by gathering appropriate secondary data)
Time for teachers to provide feedback and verify the authenticity of students' work.
Hint
In most cases, the bulk of this time is typically dedicated to data collection in the laboratory or to sourcing high-quality databases that provide reliable statistics to support the investigation's hypothesis.
Types of Investigation
The different types of data collection and/or analysis suitable for use in the scientific investigation are:
Hands-on data collection in the laboratory
The use of simulation(s)
The use of database(s)
Fieldwork
Hands-on Data Collection in the Laboratory
This method involves students designing and conducting experiments to gather primary data through direct manipulation of variables and observation of outcomes.
While more commonly used in subjects like chemistry or biology, it can still be applied in ESS when the investigation relates to environmental systems (such as analyzing soil pH, testing water quality, or measuring the rate of decomposition under different conditions).
Laboratory investigations allow for strong control over variables and typically produce reliable data, making them a solid option when feasible.
However, in ESS, this method is less frequently used than in other sciences, due to the often broader, systems-based nature of the subject.
Fieldwork
Field-based investigations allow students to collect primary data directly from the environment, such as:
Conducting biodiversity surveys,
Measuring water turbidity in local streams, or
Comparing soil compaction in different land-use areas.
This method helps students connect theory to real-world systems and observe environmental interactions firsthand.
Fieldwork is a valuable approach in ESS and is moderately common, especially when local ecosystems or environmental issues are being studied.
However, the practicality of fieldwork depends on accessibility, school resources, and safety considerations.
Tip
Students should discuss their plans with their teacher to ensure the investigation is feasible and meaningful.
Use of Simulations
Simulations are computer-based tools that model environmental systems or processes, such as:
Climate change projections
Population dynamics
Ecological succession
This method is particularly useful when studying large-scale or long-term systems that cannot be physically observed or experimented on.
Simulations produce primary data if they allow the student to manipulate variables and gather varying results.
However, they must show variability (simulations that return the same outcome each time or restrict variable control are not suitable).
Simulations are moderately common in ESS and can be very effective if chosen carefully.
Tip
Students must explain why the simulation was selected and include screenshots and clear descriptions of the data collection process.
Use of Databases
Databases provide access to a vast range of secondary data collected by reputable organizations, such as:
The World Bank,
NASA,
UNEP, or
Local government agencies.
This method is ideal for investigating large-scale environmental trends, such as:
Air pollution levels across cities,
Changes in forest cover, or
CO₂ emissions over time.
Database investigations are common in ESS because they enable exploration of real-world data at local, regional, or global scales.
Students must:
Clearly cite their sources,
Explain how the data was filtered or selected, and
Demonstrate critical analysis of the data’s reliability and relevance.
Tip
Using more than one database is recommended to ensure depth and validity.
Use of Spreadsheets for Data Analysis
Regardless of how data is collected, all students are expected to use spreadsheets (e.g., Excel or Google Sheets) to organize, process, and analyze their data.
This includes creating tables, graphs, trendlines, and performing statistical analysis such as calculating means, standard deviations, or correlations.
Spreadsheets are essential for turning raw data into meaningful conclusions and help students demonstrate a thorough understanding of data interpretation.
Their use is universal across all investigation types and is a requirement for demonstrating competence in processing and presenting scientific data in ESS.
Surveys and Questionnaires
Surveys and questionnaires allow students to collect primary data on human behaviors, perceptions, or environmental attitudes.
This method is useful when the research question focuses on social or behavioral aspects of environmental issues, such as:
Community awareness of recycling practices, or
Attitudes toward conservation.
For surveys to be effective, they must be carefully designed to:
Ensure clarity
Avoid bias
Gather statistically valid results.
Sample size, question types, and analysis methods should be considered early in the planning stage.
Hint
Though less commonly used in ESS, surveys can be powerful when combined with other methods or when the research question centers on the human-environment relationship.
Integration of Methods
Students are encouraged to combine different methods in their ESS Internal Assessment to enhance the depth and validity of their investigation.
Example
For instance, a student might collect data through fieldwork and analyze it using spreadsheets, or use simulations alongside databases to support broader environmental insights.
Regardless of the chosen approach, it is essential that students provide a clear justification for their methodology, explaining why it is appropriate for answering their research question.
They must also ensure transparency in how data is sourced, selected, and processed, including proper citation and documentation (e.g., screenshots, web addresses, or filtering methods).
Note
Most importantly, students should apply critical thinking throughout such as:
Evaluating the reliability of their sources
The variability of their data
Acknowledging any limitations that could impact the interpretation of their findings
Group Work
Depending on the resources available, it may be possible for students to work in groups during the data collection part of the investigation. The rules for group work are rather complex, but can be summarised as follows:
The maximum number of students in a group is three.
Each student must formulate their own research question.
A student can choose a different independent variable from the other members of the group, or the same independent variable, but a different dependent variable from the other members.
A student cannot use the same raw data as another member of the group, however, they may use different data from that used by other group members from a larger set of data that was collected together.
Each student must submit their own individual report, clearly indicating that they worked as part of a group.
All submitted work must be the work of the individual student; a group report is not permitted.
Hint
It is also possible to do a class collaboration where data is collected in a large-scale activity.
In this case, the data is treated as if it came from a database.
Note
Because of the complexity of the rules, it is strongly recommended that any students considering group workdiscuss the rules and requirements with their teacher beforehand to avoid any issues related to academic honesty.
Class collaboration to set up a database:
A school may take part in a large-scale activity collecting data to generate a database using standardized protocols.
If a student decides to utilize this database to answer their research question, then the investigation must be treated as a database investigation.
In such a case, the methodology should focus on how the data is filtered and sampled from the whole database, in the same way as if the data were wholly acquired from an external source.
Required Sections
The internal assessment task involves the design, implementation, and completion of an individual investigation of an environmental systems and societies (ESS) research question.
The investigation is submitted as a written report.
Any investigation used for internal assessment should be specifically designed by the student to address the assessment criteria.
Students must be provided with a copy of the assessment criteria when the requirements of the investigation are explained to them.
The scientific investigation is assessed through a written report.
Although the IB offers no specific guidance as to the structure of the report, it is recommended that it be written in the form of a laboratory report (lab report) or scientific paper.
Tip
The following is a recommended structure, however, it is by no means mandatory that students follow this structure.
Sections marked with a * are required by the IB.
This component is internally assessed by the teacher and externally moderated by the IB at the end of the course.
The internal assessment consists of one task: the individual investigation (30 marks).
The individual investigation is an open-ended task in which the student gathersandanalyses data in order to answer their own formulated research question.
Note
The requirements are the same for both SL and HL.
A title that reflects the aims or purpose of the investigation*
Candidate’s personal code (and all group members’ personal codes, if applicable)*
Word count*
A brief introductory paragraph that introduces the reader to the investigation
The Research question: The research question needs to be unique to the student
Background context or research
Hypothesis (Students are permitted to formulate a hypothesis for the outcome of the investigation, though this is not required nor will it be assessed. It may, however, help frame the investigation and therefore be of value to the success of the student)
Experimental variables (independent, dependent and control)
Procedure or method (including a list of apparatus and chemicals in case of fieldwork and lab reports; if not, a link and screenshot of the used database)
Risk assessment
Raw data
Processed data
Graph(s)
Conclusion (solution to the problem)
Evaluation
Works cited
Word Count
The maximum overall word count for the report is 3,000 words. The following are not included in the word count:
Charts and diagrams
Data tables
Equations, formulae and calculations
Citations/references (whether parenthetical, numbered, footnotes or endnotes)
Bibliography
Headers
Note
If a report exceeds 3,000 words, the examiners are not required to read the entire report.
Tip
The IB recommends that if large amounts of data have been collected, students should include only a sample of the data.
Note
A cover page and table of contents are not required in the IA.
Appendices are recommended as they will not be read by the examiner.
Any relevant information must be included within the main body of the report.
If the report contains excess raw data, a sample of data at relevant intervals should be included.
Academic Honesty
The IB takes academic honesty very seriously.
Any work or ideas that are not the work of the student must be clearly referenced.
This also includes any images or figures that are used in the report. The report should also include a works cited list.
Note
The style of referencing used can be determined by the student (or the school) and must be consistent throughout the report.
To maintain academic integrity, the authenticity of a student’s Internal Assessment (IA) must be verified. Teachers may assess authenticity through direct discussion with the student about the content and development of their work, as well as by reviewing one or more of the following:
The student’s initial proposal or planning documents
The first draft of the investigation
The sources and references cited in the final version
The writing style, compared with work previously known to be the student’s
The results of analysis by a plagiarism detection tool, such as Turnitin
View Environmental systems and societies (ESS) IA Exemplars
And thousands of other examples from high-scoring students.