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Experimental Design Notes 3

Science world of biology

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28 views

Experimental Design Notes 3

Science world of biology

Uploaded by

dandona112011
Copyright
© © All Rights Reserved
Available Formats
Download as KEY, PDF, TXT or read online on Scribd
You are on page 1/ 14

Bell Ringer

List three procedures discussed the first day


of school.
Experimental Design

ESSENTIAL QUESTION: HOW DO SCIENTISTS


PROPERLY DESIGN AND CARRY OUT AN EXPERIMENT?
Scientific Method

Scientific experimentation is carried out with the


scientific method in order to able to confidently
draw conclusions.
Steps of the Scientific Method
1. Make an observation and pose a question
2. Form a hypothesis-easily written as an if-then
statement.
3. Make a prediction (can be included in hypothesis)
4. Design an experiment
5. Analyze Data/ Draw a conclusion
Observation-the act of perceiving using the senses

Let’s see how observant you are.


The next slide will be shown to you for 30
seconds. Record as many observations as you
can about the slide.

Ready?
Observation
Observation Questions

What color is the car that is off the carrousel?


red
How many portable toilets are there in the
picture?
3
What appears on each door of the portable
toilet?
Crescent moon
What animal escaped the zoo?
lion
What are the seals eating?
fish
How many bowling pins are knocked down?
2
Hypothesis- a proposed explanation for the way a
particular aspect of the natural world functions.

The hypothesis can easily be written as an if-


then statement, though it is not the only way
to write one.

For example: If I increase my time studying


then I will get better grades.
Hypothesis Practice

While holding a flashlight you noticed the


size of the illuminated (lighted) area was
changing as you were walk.

Write a hypothesis using an if-then statement


proposing what factor is causing the size of
the illuminated area to change.
Prediction- a statement that forecasts what would
happen if the hypothesis were true.

A prediction is record for each hypothesis.


Can be embedded in the hypothesis

Experiment- Used to test the hypothesis by


gathering reliable data.
Many experiments are called controlled
experiments. They have
Control Group- the normal group or a group that
provides a standard for comparison.
Experimental Group-same as the control group
except one factor is changed (Independent
variable)
Variables

Independent Variable-The manipulated


variable.
It is the variable that the experimenter is adding to
the experimental group to see how it compares to the
control group.
An easy way to remember it is that the independent
variable Changed!
Dependent Variable- the responding variable
or what is being measured or counted
Type of Data to Collect

Quantitative Data- measurable using


instruments.
Example: The illuminated area is 10cm when the
flashlight is 8cm away from the chalk board.
Qualitative Data-gathered through your
senses (sight, smell, hear, touch, taste)
When the illuminated area got big students notice it
was more dim.
Cautions in Science

Inferences- make a conclusion on the basis


of facts and previous knowledge rather than
direct observation.
Waldo Picture- Some of you may have made
inferences about what animal escaped the zoo.
Bias-making a judgment based on prior
knowledge.
Theory

After a lot of experimentation…..

A scientific theory is a well-substantiated


explanation of some aspect of the natural
world that is acquired through
the scientific method and repeatedly tested
and confirmed, preferably using a written,
pre-defined, protocol of observations and
experiments.
Closing

Tell me one or more things you learned from


this presentation.

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