Observations

1
Observations Inferences do
n't decide too soon
2
Observations Inferences Observations
statements of things detected using our senses
3
Observations Inferences Observations
statements of things detected using our
senses e.g. colour of a rock
4
Observations Inferences Observations
statements of things detected using our
senses e.g. colour of a rock Indirect
Observations not able to be directly detected.
Specialized instruments must be used.
5
Observations Inferences Observations
statements of things detected using our
senses e.g. colour of a rock Indirect
Observations not able to be directly detected.
Specialized instruments must be used. e.g.
radiation use a Geiger counter
6
Qualitative Observations made without
measurement.
7
Qualitative Observations made without
measurement. e.g. colour
8
Qualitative Observations made without
measurement. e.g. colour Quantitative
Observations measured values
9
Qualitative Observations made without
measurement. e.g. colour Quantitative
Observations measured values e.g. mass
10
Inference (conclusion) a judgment based on
observations. These are not directly observed.
They require making decisions.
11
e.g. Iodine can be used to test for starch.
Iodine solution is yellow but in the presence
of starch turns bluish black
12
e.g. Iodine can be used to test for starch.
Iodine solution is yellow but in the presence
of starch turns bluish black test tube
1 test tube 2
Observations Inferences (conclusions)
Test tube 1
Test tube 2
13
e.g. Iodine can be used to test for starch.
Iodine solution is yellow but in the presence
of starch turns bluish black test tube
1 test tube 2
Observations Inferences (conclusions)
Test tube 1 yellow
Test tube 2
14
e.g. Iodine can be used to test for starch.
Iodine solution is yellow but in the presence
of starch turns bluish black test tube
1 test tube 2
Observations Inferences (conclusions)
Test tube 1 yellow
Test tube 2 bluish-black
15
e.g. Iodine can be used to test for starch.
Iodine solution is yellow but in the presence
of starch turns bluish black test tube
1 test tube 2
Observations Inferences (conclusions)
Test tube 1 yellow no starch present
Test tube 2 bluish-black
16
e.g. Iodine can be used to test for starch.
Iodine solution is yellow but in the presence
of starch turns bluish black test tube
1 test tube 2
Observations Inferences (conclusions)
Test tube 1 yellow no starch present
Test tube 2 bluish-black starch present
17
Variables Constants Variable anything that
can change during an experiment
18
Variables Constants Variable anything that
can change during an experiment Most
experiments all variables except two are kept
constant. The two that are allowed to change
are called the independent and the dependent
variables.
19
Independent Variable the scientist chooses how
this variable changes. You can usually pick out
the independent variable because its values are
regular (e.g. time 30s, 60s, 90s, 120s, etc)
20
Independent Variable the scientist chooses how
this variable changes. You can usually pick out
the independent variable because its values are
regular (e.g. time 30s, 60s, 90s, 120s,
etc) Dependent Variable is allowed to change
freely. The values the scientist gets depend on
the independent variable
21
(No Transcript)
22
Controlled Variables otherwise known as
constants
23
Controlled Variables otherwise known as
constants e.g. A speedboat acceleration test is
done to test the engine's output. Speed
measurements are taken at 10s, 20s, 30s, 40s,
50s, and 60s.
24
Controlled Variables otherwise known as
constants e.g. A speedboat acceleration test is
done to test the engine's output. Speed
measurements are taken at 10s, 20s, 30s, 40s,
50s, and 60s. Independent variable
25
Controlled Variables otherwise known as
constants e.g. A speedboat acceleration test is
done to test the engine's output. Speed
measurements are taken at 10s, 20s, 30s, 40s,
50s, and 60s. Independent variable time
26
Controlled Variables otherwise known as
constants e.g. A speedboat acceleration test is
done to test the engine's output. Speed
measurements are taken at 10s, 20s, 30s, 40s,
50s, and 60s. Independent variable
time Dependent variable
27
Controlled Variables otherwise known as
constants e.g. A speedboat acceleration test is
done to test the engine's output. Speed
measurements are taken at 10s, 20s, 30s, 40s,
50s, and 60s. Independent variable
time Dependent variable speed
28
Controlled Variables otherwise known as
constants e.g. A speedboat acceleration test is
done to test the engine's output. Speed
measurements are taken at 10s, 20s, 30s, 40s,
50s, and 60s. Independent variable
time Dependent variable speed Controlled
variables
29
Controlled Variables otherwise known as
constants e.g. A speedboat acceleration test is
done to test the engine's output. Speed
measurements are taken at 10s, 20s, 30s, 40s,
50s, and 60s. Independent variable
time Dependent variable speed Controlled
variables wind speed throttle
position boat weight
30
Alternative experiments two groups are set up
with the independent variable different between
them.
31
Alternative experiments two groups are set up
with the independent variable different between
them. Control Group everything is left alone
32
Alternative experiments two groups are set up
with the independent variable different between
them. Control Group everything is left
alone Test Group some change is made to the
independent variable
33
Alternative experiments two groups are set up
with the independent variable different between
them. Control Group everything is left
alone Test Group some change is made to the
independent variable -the two groups are
compared to see the difference in the
dependent variable
34
e.g. Testing a new drug to cure the common
cold Test group
35
e.g. Testing a new drug to cure the common
cold Test group is given the new drug
36
e.g. Testing a new drug to cure the common
cold Test group is given the new
drug Control group
37
e.g. Testing a new drug to cure the common
cold Test group is given the new
drug Control group doesn't receive the new
drug
38
e.g. Testing a new drug to cure the common
cold Test group is given the new
drug Control group doesn't receive the new
drug Dependent variable
39
e.g. Testing a new drug to cure the common
cold Test group is given the new
drug Control group doesn't receive the new
drug Dependent variable length of time the
illness lasts