MAKING QUALITATIVE AND QUANTITATIVE OBSERVATIONS

Most of the observations that you make are QUALITATIVE OBSERVATIONS; that is, you use only your senses to obtain the information.  Sometimes we want more information than our senses alone can give us and we include a reference to some standard unit of measure.  Observations that involve number or quantity are QUANTITATIVE OBSERVATIONS.  Quantitative observations help us communicate specifics to others and provide a basis for comparisons.  The following statements are examples of quantitative observations that could be made about a plant.

1.)	One leaf is 10 cm long and 6 cm wide.  (metric ruler)
2.)	The mass of one leaf is 5 g.  (balance)
3.)	The temperature of the room in which it grows is 22 C.  (thermometer)
4.)	This plant’s leaves are clustered in groups of five.
5.)	Each flower is as wide as 3 paperclips placed end to end.

Quantitative observations made with instruments such as rulers, meter sticks, balances, and graduated cylinders or beakers, give us specific and precise information.   Although approximations and comparisons are not as precise, they are also quantitative observations.