Explain the difference between an experiment and other types of scientific investigation.
Recognize and explain that authentic scientific investigation frequently does not parallel the steps of “the
scientific method”.
Students will:
explain that an authentic scientific investigation frequently does not parallel the steps of
“the scientific method”.
explain the difference between an experimental investigation and other types of scientific
investigation.
o experimental investigation – used when one variable is defined/known and a test is done
o descriptive investigation – used to observe, describe, or identify
o comparative investigation – used to compare, differentiate, or classify
Teacher Hints for “Introduction to Science Process”:
Digital textbook resources can be accessed at www.thinkcentral.com..
Students need to understand that scientists do not only learn from performing investigations but also from reading non-fiction references materials, such as journals,
newspapers, reference books, etc. This research is beneficial before writing a hypothesis or creating an investigation.
Investigations that follow the “scientific method” typically include a question/problem (or purpose), hypothesis, experiment (materials and procedures), results, conclusion
(analysis of results), and application. Other investigations may include creating and using models, repeated observations, research, inquiry, problem/solution, and the
engineering process.
Some of the experimental investigations performed in the classroom should model 10 repeated trials (expectation for the elementary science fair/expo process). It may be
more appropriate, at times, to use a large experimental group (10 or more in a group) instead of repeated trials.
When experimenting, students will need to understand the need to manipulate one variable, to control variables (keeping all other conditions constant) and to test a control
group (the normal condition within the context of the experiment). For example, when trying to determine which type of soil supports the growth of marigolds, the following
would need to be considered in the design of the experiment:
o The variable being manipulated would be different types of soil.
o The variables that need to be controlled would be soil amount, water amount, plant container, plant size, and sunlight exposure.
o The possible control group that would need to be tested is the soil that is most prevalent in the area where the marigolds will be planted.
Repetition (multiple trials yielding stable and consistent data; reliability) differs from replication (experiment done by others to measure accuracy of data).
As scientists, students will be making observations and inferences in all types of investigations. Data that is collected through the five senses (observable/qualitative) and
through the use of scientific and measurement tools (measurable/quantitative) become their observations. Students make inferences when they interpret or give their own
meaning to the data they have collected.
Students should work on common investigations so that they are able to compare their results across groups. When differences arise, have students compare the different
methods each group used to gather their data.
While conducting investigations, students will use scientific tools. Metric measurements should be used when measuring these physical properties of matter:
o mass/weight in grams, kilograms – balance scale/pan balance, spring scale
o volume in milliliters, liters – graduated cylinder (most accurate), beaker, flask, measuring cup
o linear in centimeters, meters, kilometers – ruler, meter stick, meter tape
o time in seconds – stop watch
o heat energy in Fahrenheit and Celsius – thermometer