Science in Punggol study guide · Article 0002 of 20
An observation records what you notice or measure. An inference uses that evidence to suggest an explanation. A strong science answer makes the difference clear, then connects the evidence to the relevant concept.
For example, droplets on a cold bottle are an observation. Saying that the bottle is leaking is an inference. The droplets alone do not tell us how the water reached the outside.
On this page: Describe what you observed · Consider more than one explanation · Connect the evidence to a concept · Worked question
Describe what you observed
Observations can come from looking, listening, touching where safe, or using an instrument. “There are droplets on the bottle” and “The thermometer reads 15 degrees Celsius” describe evidence. “The bottle must have a hole” adds an interpretation.
Include details that matter. Instead of saying “The plant looks different”, describe which leaves changed colour or record its height. Words such as “better” and “stronger” need a clear meaning before they can help an answer.
A measured number is still only as useful as the method used to collect it. A thermometer placed incorrectly can give a misleading reading. Recording a number does not remove the need to check how it was measured.
Consider more than one explanation
An inference is a reasoned interpretation. It may be sensible without being certain. Holes in a leaf may suggest that an animal fed on it, but the holes do not identify which animal or when it happened.
A wet pavement could result from rain, cleaning or spilled water. Ask what extra evidence would help: were nearby surfaces wet too, was rain observed, or was someone cleaning the area? Each answer can help distinguish the explanations.
During a home science discussion, separate “What did we observe?” from “What might explain it?” This keeps a plausible idea open to checking.
Connect the evidence to a concept
Water vapour in the air can lose heat and condense into liquid water on a cold bottle. The droplets need not have passed through the bottle wall. The water came from water vapour in the surrounding air.
To examine this explanation, begin with a dry bottle exterior and a secure lid. Observe where droplets form. A similar bottle at room temperature can provide a comparison, provided other relevant conditions are kept the same.
Naming “condensation” is only part of the explanation. State what changed, where it came from and why the change occurred. In this case, water vapour lost heat at the cold surface and became liquid water.
An explanation should also fit the question’s evidence. Do not add a damaged lid or hole unless the question or observations support that idea.
Worked question
Question: In this hypothetical situation, a closed bottle was dry outside before it was cooled. Later, droplets appeared on its outside surface. A pupil says, “Water vapour in the air condensed on the cold surface.” Which statement is the observation, and which is the inference?
Worked explanation: The appearance of droplets is the observation. The statement about condensation is an inference that uses a science concept to explain the change. A fuller explanation says that water vapour in the surrounding air lost heat at the cold surface and became liquid water.
Common mistake: Do not write that “air turned into water”. Water vapour is the part that condensed. When checking an explanation, look for three parts: the evidence, the relevant concept, and the link showing how the concept accounts for the result.
