Science in Punggol study guide · Article 0019 of 20

Compare solutions using a stated purpose and relevant evidence. A design that performs better in one test may still have limitations or be unsuitable for another job.

The question is what the solution needs to achieve and how the results support the choice.

On this page: Define the requirements · Compare under matching conditions · Consider resources and living things · Worked question: does insulation stop all heat loss?

Define the requirements

A cooking utensil’s handle should reduce heat transfer to the user’s hand. A poor conductor of heat may be suitable. For its cooking surface, good heat conduction may be useful instead.

The same property can help one part and hinder another. An answer about strength does not explain a heat-transfer requirement unless strength is also part of the stated task.

Several requirements may compete. A carrying container might need low mass, durability and resistance to water. Evidence about one property does not settle the whole choice.

State the most important requirement before deciding which result matters. This makes the recommendation understandable and allows someone else to check it.

Compare under matching conditions

Consider a hypothetical test of two insulating covers. Identical containers hold equal volumes of water at 45°C. Both use matching lids and covers of equal thickness. They stand in the same room for ten minutes.

Water in A reaches 39°C, a decrease of 6°C. Water in B reaches 35°C, a decrease of 10°C. A results in the smaller temperature decrease under these conditions.

This supports choosing A when reducing cooling is the goal. It does not show that A is best at every thickness, in wet conditions or for every product. Those comparisons would need further evidence.

Use the actual values rather than only saying “A did better.” The values show how the options differed in the measured test.

Consider resources and living things

Some choices affect an environment. Removing plants can change available food, shelter or shade, depending on the organisms present. Explain a stated relationship rather than writing only “it harms nature.”

If an insect feeds on a particular plant, fewer of those plants can mean less food for that insect. Further effects depend on the other relationships described. Do not assume that every animal uses the same plant.

Enrichment: resource comparisons can also consider an object’s lifespan, materials and number of reuses. “Reusable is always greener” does not settle every comparison; the process and amount of use can matter.

These wider questions require more evidence than a single material test. Name the tradeoff, such as lower mass versus greater durability, instead of pretending that every requirement improves together.