Transcript No Slide Title

What is science?
An organized way of
using evidence to
learn about the
natural world.
Thinking Like a
Scientist
Scientific thinking
usually begins with
Observations
ObservationThe process of gathering
information about events or
processes in a careful, orderly
way.
DataThe information gathered
from observations.
After initial observations, the
researchers will propose one or
more hypotheses.
A hypothesis is a
proposed scientific
explanation for a set of
observations.
designing an
6 concepts of experimental design
independent variable
dependent variable
constants
control group
experimental group
repeated trials
A variable is something that
changes.
independent variable
the variable that is changed
on purpose by the experimenter
aka cause, stimulus, reason,
manipulated variable, etc.
This is the ‘’if” part of a hypothesis.
Independent variable
(manipulated variable)
with units is located on
the x axis when graphing
DRY MIX
M= independent
or Manipulated
variable is on
the X axis
dependent variable
the variable that responds
aka effect(s), result(s), responding
variable, etc.
This is the ‘’then” part of a
hypothesis.
Dependent variable with
units is located on the y
axis when graphing
DRY MIX
D= dependent
variable is on
the Y axis
constants
all factors which are NOT allowed
to change during the experiment
control group
the group (standard) to which
everything is compared
experimental group
the group(s) being tested with the
independent variable
Each test group has only one factor
different from the other test groups:
the independent variable.
repeated trials
the number of times the experiment
is repeated
The more times you repeat the
experiment, the more VALID your
results are.
The
IVCDV
chart
is used to design an experiment.
iv
constants
dv
fertilizer
The variable (factor) that you will
change is the independent
variable.
0 drops
These are the fertilizer amounts
varied by the experimenter.
2 drops
4 drops
6 drops
Plants with no fertilizer make up
the control or control group.
iv
fertilizer
constants
dv
plant growth
0 drops
2 drops
4 drops
6 drops
The variable (factor) resulting
from the independent variable is
the dependent variable.
iv
fertilizer
constants
amt. of water
dv
plant growth
type
of soilthat must NOT change
These
factors
0
dropsare the
during experimentation.
They must remain
amt.
of
soil
2 drops
constant.
type of plant
4 drops
6 drops
type of planter
size of planter
type of light
location
What is this called? What are these called?
What are these called?
What is this called?
The plant growth that you
observe here can be called . . .
 the results (of adding fertilizer)
 the response (to adding fertilizer)
 the effects (of adding fertilizer)
0
2
4
6
What do you do if you want to test the
type of soil instead of fertilizer?
iv
type
of soil
fertilizer
constants
amt. of water
dv
plant growth
fertilizer
type
of soil
amt. of soil
type of plant
Fertilizer
becomes
a constant.
Type of soil
becomes
the IV.
type of planter
size of planter
type of light
location
Design an experiment
to test the strengths
of various sunscreen on
aliens.
5 spf
10 spf
15 spf
20 spf
Evaluate the experimental
design in the next two
slides.
forming a
V Chart
iv
constants
fertilizer
amt. of water
dv
plant growth
type of soil
amt. of soil
type of plant
type of planter
size of planter
type of light
location
If fertilizer is added to plants,
then plant growth will improve.
V Chart
Independent Variable
If independent variable + verb,
Dependent Variable
then dependent variable + verb.
hypothesis
Hypothesis and Theory
So what’s the difference between
a hypothesis and theory?
Remember……..
Hypotheses are tentative and testable
statements.
For example: If a fish lives in water with
pH levels below six, it will not survive.
Theories are well established and
highly reliable explanations
Theories are not set in stone and are
subject to change as new discoveries
are made.
For example: All matter is made up of
Subunits called atoms