Which type of observation yields numerical data?

• A. Quantitative observation
• B. Qualitative observation
• C. State
• D. Lustre

Answer: (A)

Observations that involve measurements or counting produce numerical data. This is the idea behind quantitative observations: they use numbers to describe what’s observed, like a length of 12 cm, a mass of 30 g, or a temperature of 22.5°C. Tools such as rulers, balances, thermometers, and timers are used to get those numbers, and the data can be compared or analyzed statistically.

In contrast, qualitative observations describe qualities without numbers—things like color, texture, smell, or state of matter. Describing a sample as blue and shiny gives descriptive information but not a number, so it’s qualitative data. States of matter and lustre are typical qualitative descriptors.