Types of Observations
Quantitative Observation:
 A quantitative observation is a measured value (i.e. a measured quantity).
This means that the observation will have a number associated with it.
 In science class, almost every number you write must have UNITS!
Examples:
 John has a mass of 70 kg
 The volume of juice in my lunch is 250 mL
Qualitative Observation:
 A qualitative observation describes a property (i.e. a quality) of an object.
This means that the observations will have words instead of a number.
Examples:
 Sanjay has black hair
 Fatima takes the bus to and from school
 Terrell is the tallest in the class
Practice:
 Indicate whether each observation is quantitative (QT) or qualitative (QL).
a) The concert was very loud. Qualitative.
b) The reaction lasted for 48 seconds. Quantitative.
c) The grass was green. Qualitative.
d) The object had a volume of 4.9 litres. Quantitative.
e) The man was six feet tall. Quantitative.
f) The length of the trip was 675 km. Quantitative.
g) The sandpaper was rough. Qualitative.
h) When we added sugar to sulfuric acid it turned black and then it rose to a
height of 20 cm. Quantitative.
i) The blue object had the smallest mass. Qualitative.
j) The object exploded into four pieces. Qualitative.
Activity:
 Use the table below to make as many observations as you can for a burning candle under
a water-filled test tube. For qualitative observations detailed point form is sufficient.
Quantitative Observations
Before
Burning
The
Candle
While
The
Candle
Is
Burning
After
Burning
The
Candle
Qualitative Observations
Qualitative Observation or Quantitative Observation?
Circle QL if the statement represents a QUALITATIVE observation or circle QT if the statement
represents a QUANTITATIVE observation. Some observations have both qualities and quantities.
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL
1. The candle is cylindrical in shape.
2. It is about _____ centimeters in diameter.
3. The length is about _____ centimeters.
4. The length decreased during the observation period.
5. The amount of decrease was about _____ centimeters per half hour.
6. The candle is translucent.
7. It is white (or yellow, etc.).
8. It has a slight odor.
9. It has no distinct taste.
10. It is solid.
11. It is soft enough to be scratched with a fingernail.
12. A relatively thick string extends about 1-cm from the upper end of the candle.
13. It is made of _____ (#) strands of string braided/twisted together.
14. The string or wick ignites when a lighted match is held close for a few seconds.
15. The wick then burns continuously.
16. The burning candle makes no sound.
17. The burning candle remains cool while the wick burns.
18. It is warm near the top.
19. The candle material is softer around the top as it burns.
20. The flame flickers in response to air currents.
21. When the flame flickers, smoke comes from it occasionally.
QT or QL
QT or QL
QT or QL
QT or QL
22. When no currents disturb it, the flame is shaped like an elongated teardrop.
23. The flame begins about 1-cm above the top of the candle.
24. The flame is a shade of blue at its base.
25. Immediately around the wick in a region about 1-cm wide and extending about 1cm above the top of the wick, the flame is dark.
26. This dark region is roughly conical in shape.
27. Around this zone and extending about 1-cm above the dark zone is a region,
which emits yellow light that is bright, but not blinding.
28. The flame has sharply defined sides but a ragged top.
29. The wick is white where it emerges from the candle but is dark as if burnt from
the base of the flame to within 2-mm of the top.
30. The last 2-mm of the wick glows red.
QT or QL
QT or QL
QT or QL
QT or QL
QT or QL