This document shows how the summative task Balanced and Unbalanced Forces assesses the mandated WA Curriculum (SCSA) Year 4 Science content, and explains the design of the task and marking key. It is for teacher planning and moderation and is not given to students.
Curriculum content assessed
| Strand / sub-strand | Content description (SCSA Year 4) |
|---|---|
| Science understanding — Physical sciences | "Forces are exerted by one object on another through direct contact, such as friction, or from a distance, such as magnetism and gravity." |
| Science inquiry — Processing, modelling and analysing | "Organise and represent data using tables, column graphs and models to identify patterns" (here, representing forces with arrow models). |
| Science inquiry — Communicating | "Communicate ideas using scientific vocabulary." |
Alignment with the Year 4 achievement standard
The Year 4 achievement standard states that students "observe and investigate forces that operate from a distance, such as magnetism, and by direct contact, such as friction." This task assesses exactly that distinction, and adds the balanced/unbalanced idea used to explain movement.
| Situation | What it asks | Content / standard link |
|---|---|---|
| 1 — Book on a table | Draw the two arrows; decide balanced/unbalanced. | Representing forces; balanced forces (no motion). |
| 2 — Ball on grass | Name friction; classify it; explain it is unbalanced while slowing. | "Direct contact, such as friction." |
| 3 — Two magnets | Name magnetism; classify as a force at a distance. | "From a distance, such as magnetism." |
| 4 — Tug-of-war | Draw unbalanced arrows; explain the resulting motion. | Unbalanced forces change motion; representing forces. |
| 5 — Sorting task | Classify five forces as contact or at a distance. | The core Physical sciences content description. |
How the marking key reflects the standard
The two highest-weighted criteria — Representing forces with arrows (30) and Balanced and unbalanced forces (30) — target the modelling of forces and the balanced/unbalanced reasoning that runs through the task. Contact and non-contact forces (25) directly assesses the mandated contact-vs-at-a-distance distinction. Communication and scientific vocabulary (15) assesses the communicating content. The High / Sound / Limited descriptors mirror the SCSA judging-standard language.
Addressing a key misconception
Why this task is valid and fair
- It builds on the taught sequence. Students meet pushes/pulls, contact vs at-a-distance, and balanced/unbalanced with arrows (Lesson 13), investigate friction (Lesson 14) and explore magnetism and gravity (Lesson 15) before this task — so it assesses developed learning.
- It uses multiple, everyday situations. Analysing several familiar contexts (a book, a ball, magnets, a tug-of-war) gives a fuller, fairer picture of understanding than a single item, and the drawing component lets students show understanding visually.
- It is inclusive. Arrow diagrams reduce the writing load; sentence starters, a word wall and scribing can be offered as adjustments without changing the science being assessed.