IB MYP Sciences: The Four Assessment Criteria in Practice -- Revision Notes

The assessment revision notes list the four criteria and their scoring structure. These notes go further, working through what genuinely top-band evidence looks like for each criterion with a worked example, since knowing a criterion’s name is a different skill from producing investigative work that satisfies its top achievement-level descriptors.

Criterion A: Knowing and understanding

Top-band evidence develops and applies scientific knowledge (facts, ideas, concepts, processes, laws, principles, models and theories) to solve problems and express scientifically supported judgments – not simply recalling a definition, but using that knowledge to reach and justify a conclusion in an unfamiliar context.

Worked example: Asked to explain why a metal spoon feels colder to the touch than a wooden spoon at the same room temperature, top-band evidence does not stop at naming “thermal conductivity” – it applies the concept of conduction rate to explain why heat transfers away from the hand faster through the metal, and uses this reasoning to make a scientifically supported judgment about the actual temperature (identical) versus the perceived temperature (different).

Criterion B: Inquiring and designing

Top-band evidence designs, analyses and performs a genuine scientific investigation – meaning the student formulates their own testable research question and hypothesis, identifies variables to control, and justifies their chosen method, rather than simply following a prescribed worksheet procedure.

Worked example: A lower-band task might follow fixed instructions to measure how temperature affects reaction rate. Top-band Criterion B evidence instead involves the student proposing their own specific, testable research question (e.g. how does the concentration of a particular reactant affect reaction rate under otherwise controlled conditions), justifying why the chosen variables should be controlled, and explaining the reasoning behind the chosen method before carrying it out.

Criterion C: Processing and evaluating

Top-band evidence collects, processes and interprets qualitative and/or quantitative data accurately, and explains conclusions properly reached from that data – including identifying limitations in the data or method and suggesting genuine, specific improvements, not generic ones like “use more trials.”

Worked example: After collecting reaction-rate data across several concentrations, top-band evidence presents the data in an appropriately labelled graph, correctly identifies the trend, explains that trend using the relevant scientific concept (e.g. collision theory), and then evaluates a specific limitation of the actual method used (e.g. that reaction start-time was judged by eye, introducing timing error) with a specific, targeted improvement (e.g. using a colorimeter to detect the reaction’s endpoint automatically) rather than a vague suggestion.

Criterion D: Reflecting on the impacts of science

Top-band evidence evaluates the implications of scientific developments and their applications to a specific problem or issue, using varied scientific language and properly documenting the work of others – meaning genuine evaluation of real-world impact, not a one-sided description of only benefits or only risks.

Worked example: Asked to discuss the impact of a specific agricultural technology (e.g. genetically modified crops), top-band evidence presents both a genuine benefit (e.g. increased crop yield in specific conditions) and a genuine limitation or risk (e.g. ecological or economic concerns raised in published sources, properly cited), reaching a reasoned evaluative judgment rather than presenting only one side or a purely descriptive account of the technology.

Applying this across discrete, modular and integrated course models

Because the full syllabus guide confirms schools can deliver MYP Sciences as discrete subjects (separate biology, chemistry, physics), a modular course, or a fully integrated science course, the four criteria’s descriptors stay identical regardless of which model your school uses – what changes is only the specific scientific content an investigation draws on. A student in a discrete-biology class and a student in an integrated-science class are held to the exact same Criterion B (inquiring and designing) or Criterion C (processing and evaluating) standard; revision of the criteria themselves therefore transfers directly across course models even where the underlying content differs.

Why the four criteria are usually assessed through one connected investigation

A single well-designed practical investigation typically generates evidence for all four criteria at once: the scientific concept underpinning the investigation (Criterion A), the design of the investigation itself (Criterion B), the processing and evaluation of the resulting data (Criterion C), and, where relevant, a reflection on the investigation’s broader scientific or real-world significance (Criterion D). Revising each criterion as a fully separate skill, rather than practising a complete investigation that touches all four, risks preparing for an assessment structure that does not match how MYP Sciences coursework is actually usually set.

Self-test

1. What distinguishes top-band Criterion A evidence from simply recalling a scientific fact?
2. What must a top-band Criterion B investigation include beyond following a prescribed procedure?
3. Why does a vague suggestion like “use more trials” fail to demonstrate top-band Criterion C evidence?
4. What must top-band Criterion D evidence include beyond a one-sided description?
5. Why can a single practical investigation generate evidence for all four criteria at once?

Answers: 1. It applies that knowledge to reach and justify a scientifically supported judgment in context, rather than simply stating the fact or concept. 2. The student’s own testable research question and hypothesis, justified variable choices, and a justified method, rather than simply following fixed instructions. 3. Because top-band evaluation requires identifying a specific limitation of the actual method used and proposing a specific, targeted improvement, not a generic statement that could apply to any investigation. 4. A genuine evaluation presenting both a benefit and a risk or limitation, reaching a reasoned judgment, rather than describing only one side. 5. Because a well-designed investigation naturally requires scientific knowledge to underpin it (A), a designed method (B), data processing and evaluation (C), and often a reflection on its broader significance (D) all within one connected piece of work.

Official syllabus

International Baccalaureate Organization, Middle Years Programme Subject Brief – Sciences, from 2014, (c) 2015 – the same source already cited by the full syllabus guide, which first reproduced the four criteria’s names and focus areas from it.