A shared concept is an idea that appears in more than one science, such as particles moving from high to low concentration. To reuse it, write one master note for the idea and a short hook for each science. This skill saves time in 0653 revision and route planning because Combined Science asks you to cover biology, chemistry and physics in one course.
How do you build a master note?
Follow these steps.
- Name the idea in one plain sentence, with no science label.
- Write the core explanation once, with a labelled sketch or short table.
- Add one hook per science: a line for where it appears, a line for the key words, and a line for a likely question style.
- Link the hooks back to the master note by title, instead of copying text.
Hooks stay short. If a hook grows past three lines, you are probably duplicating the master note again.
Worked example
Idea: particles spread out from high concentration to low concentration (diffusion).
Master note (8 lines): particles move randomly, more leave a crowded region than arrive, so there is a net movement down the concentration difference, which continues until the particles are evenly spread. A warmer sample moves faster.
Biology hook (2 lines): gas exchange across thin surfaces, with a short diffusion distance and a steep gradient. Chemistry hook (2 lines): a coloured crystal dissolving, with the colour spreading through the water. Physics hook (2 lines): a smell crossing a room, linked to the particle model and temperature.
Count the saving. Three separate notes of 8 lines each: 3 × 8 = 24 lines. One master note and three 2-line hooks: 8 + 3 × 2 = 14 lines. You save 24 − 14 = 10 lines, and when you correct the idea you correct it once.
All the examples are invented, so check wording against your own syllabus.
What is the mistake to watch for?
Copying the master note into each science “to be safe”.
Mistaken approach: three full notes. Next month you improve one of them, and the other two now disagree.
Duplicated notes drift apart, and then you revise a wrong version without noticing.
The correction is a single source of truth. Fix the master note, and every hook is automatically right because it points to it.
Check yourself
1. A master note has 10 lines and you add four 2-line hooks. How many lines do you write, versus four full copies?
Show answer
Master plus hooks: 10 + 4 × 2 = 18 lines. Four copies: 4 × 10 = 40 lines. You save 22 lines.
2. Name two ideas you would store as a master note, and say why.
Show answer
For example, energy transfer and reading a gradient from a graph. Both are used in at least two sciences, so one core explanation serves them all and only the context differs.
3. A hook is now six lines long. What should you check?
Show answer
Check whether it repeats the master note. Move repeated parts back into the master note and keep only what is specific to that science.
Where this leads next
Next, locate a reliable current specimen so your notes match the right route. Practise with the mixed practice set.
Our teachers can help you decide how deep each hook should go in online one-to-one Combined Science tuition.