Page 31 - Science Course 1 (Book 1)

Mo. 1 - L3b What are Qualitative and Quantitative Data?

Quantitative data use numbers to describe what is This type of bridge is supported only at its two ends,
observed. but an assembly of interconnected triangles, or
trusses, strengthens it.

The I-35W bridge was a truss bridge designed in the
early 1960s.

Qualitative data Quantitative data
• Deals with descriptions. • Deals with numbers.
• Data can be observed • Data which can be
On August 1, 2007, the center section of the
Interstate-35W bridge in Minneapolis, Minnesota, but not measured. measured.
suddenly collapsed. The design and engineering • Colors, textures, smells, • Length, height, area,
processes that bridges undergo are supposed to taste, appearance, volume, weight,
ensure that bridge failures do not happen. beauty, etc. speed, time, tempera-
• Qualitative --> Quality ture, humidity, sound,
level, cost, members,
ages, etc.
• Qualitative --> Quantity

Qualitative data: Quantitative data:
After the 2007 bridge collapse, investigators needed Aroma (Smell) Cost
to use scientific inquiry to determine why the bridge Foam Size of Cup
failed. The investigators designed controlled experi-
ments to help them answer questions and test their Taste (12 ounces)
hypotheses Color of Cup Temperature
(1500 F)

The simplest type of bridge is a beam bridge, which
has one horizontal beam across two supports.

A disadvantage of beam bridges is that they tend to
sag in the middle if they are too long.
Load Compression Qualitative data: Quantitative data:
Color of Paint Cost
Texture of Brush Paint Size
Tension Strokes (20” x 20”)

Smell of the Pain Weight (3.65 kg)
Compression
Reaction Force Reaction Force

A truss bridge often spans long distances.

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