Science

Part 1: The Scientific Method - A Way of Knowing

Here we are going to take a look at each of the steps of the scientific method.

Observation

One of the steps of the scientific method is observation. We observe objects and events in the world around us through our five senses: sight, smell, touch, taste, and hearing. We can also make observations by taking measurements with instruments. Observations can be qualitative or quantitative.

Observations that are qualitative (from the word quality) are not numerical and refer to what, what kind, or to a characteristic observed.

Examples of qualitative observation

• It is light green in color (the quality is green - a visual observation)
• It has a pungent odor (the quality is pungent - an observation from smell)
• It tastes sour (the quality is sour - a taste observation)
• Its leaves are waxy and smooth (the quality is waxy and smooth - a touch observation)
• It makes a rustling sound when lightly rubbed (the quality is rustling - a hearing observation)

Observations may also be quantitative (from the word quantity). These observations give information about the amount or quantity of what is being observed. Instruments can be used to aid our senses to make more precise and accurate quantitative observations.

Examples of quantitative observation

• It is 4 cm long and 2 cm wide (measured with, say a metric ruler)
• Its mass is 3 grams (measured with a balance)
• The temperature is 22 ^oC (measured using a thermometer)
• The leaves of the plant cluster in groups of five (a count)
• The bulb is rated at 60 watts (a measure of power)

Take a look at the picture below

What do you see? That is, what do you observe using your eyes?

Square? Triangle? Star? Octagon? Arrow?

These are qualitative observations....what you see

Small square, medium square, large square

Small triangle, medium triangle, large triangle

Although the comparison about size is being given we still don't know, unless we are looking at the picture, how small the small is or how large the large is...still qualitative

The square has four sides each of equal length.

The star has five points.

Here we are beginning to see quantitative observations.

An object having four sides of equal length and an angle of 90^o at each corner. More quantitative.

An object having four sides, each of length 1.55 cm, with angles of 90^o at each corner. Here we are pretty close to being all quantitative.

Take a look at the following items. What do you observe?

Would it help to put the items in the following order?

What are the qualitative and quantitative characteristics for the items?

holes? round head? flat head? slots? threads?

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Now would be a good time to do the assignment Scientific Method Observation.

This is found back on your WebCT pages under Assignments.

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