Observation

Malay: Pemerhatian · Chinese: 观察

An observation is information gathered directly using the senses, sight, hearing, smell, touch, or using an instrument such as a thermometer or balance. The key point is that it states only what is detected, with no explanation attached. “A colourless gas is produced”, “the solution turns blue”, “the temperature rises to 45 °C” and “a white precipitate forms” are all observations. Because the SPM Chemistry papers (4541) reward precise recording, an observation should describe colour, gas, precipitate, heat or sound exactly as it appears.

For example, when zinc is added to blue copper(II) sulfate solution, valid observations are that the blue colour fades and a brown solid forms on the zinc. Notice these statements say what happens, not why. Naming the brown solid as copper, or saying that a displacement reaction has occurred, goes beyond observation, that is interpretation, which belongs to the next step. A well-written observation can often be checked by anyone repeating the experiment, because it reports only what is there to be seen, heard, smelled, felt or measured on the instrument.

The confusion to avoid, and the single most examined distinction in this chapter, is between an observation and an inference. An observation is what you actually detect; an inference is the conclusion you draw from it. “Bubbles of gas are seen” is an observation; “the gas is hydrogen” is an inference. In answers, keep them in separate sentences so the examiner can award each mark cleanly, and never write an inference where an observation is asked for.

Observation is the opening step of the scientific method and the raw material from which inferences, hypotheses and conclusions are built. Our teachers train you to record observations in exact, neutral language so you never lose these description marks.