Title: The Scientific Method Movie
1The Scientific MethodMovie
- An experiment tests an idea in a careful orderly
manner. The orderly steps used are called The
Scientific Method.
2Stating the Problem
- Example
- Which freezes faster, fresh water of salt water?
- A scientific question that can be answered by
gathering evidence.
3ResearchGathering information on the problem.
4Develop a Hypothesis
- A hypothesis is a prediction about the outcome of
the experiment. A properly worded hypothesis
should take the form of an If then statement.
Example If I add salt to fresh water, then the
water will take longer to freeze.
5Designing an Experiment
- A variable is any factor that can change in an
experiment. - The factor that you change is called the
manipulated variable or independent variable. - The responding variable or dependent variable is
what you measure or observe to obtain your
results. - A controlled variable is a factor that is kept
constant. You use the control to make a
comparison.
- Next, you need to develop a plan to test your
hypothesis. Your plan should describe the
observations or measurements you will make. - In a well designed experiment, you need to keep
all variables the same except for one.
6Example of an Experimental Procedure
- Fill 3 containers with 300 milliliters of cold
tap water. - 2. Add 10 grams of salt to container 1 and stir.
Add 20 grams of salt to container 2 and stir.
Add no salt to container 3. - 3. Place the 3 containers in a freezer.
- 4. Check the containers every 15 minutes. Record
your observations.
- The manipulated/independent variable is the
amount of salt added to the water. - The responding/dependent variable is how long it
takes the water to freeze. - The control is container 3, which has no salt
added. This allows you to compare how long it
takes regular water and salt water to freeze. - Notice that the other factors, such as the amount
of water or starting temperature are kept
constant. This ensures valid results and that
only one variable is tested.
7- Hypothesis an educated guess or prediction an
if, then statement - If ..independent variable,
- then..dependent variable.
8Example
- Independent Variable
- I feed my cat a lot of food
- Dependent Variable
- she will get fat
- If ___________________________
- then _________________________
9Remember
Try to use INCREASE and DECREASE in your
hypothesis! Ex. IF I increase the amount of food
I give my cat, THEN she will increase her weight
10Now Try it on Your Own!
- Writing a Good Hypothesis
- Just plug and chug in your variables!
11Types of Variables
- There are 2 main types of variables
- Independent Variable The variable that is
changed by the scientist the I control
variable - Dependent Variable The variable that might
change because of what the scientist changes
what is being measured
12Remember!
- Your hypothesis can TELL you what your variables
are! - Ex. If I drink Mountain Dew before bed, then I
will not sleep very much. - IV Drinking Mountain Dew
- DV the amount of sleep
13Practice
- Use this hypothesis to identify the variables
- If I leave all the lights on all day,
- then my electric bill will be
- Expensive.
- IV ______________________
-
- DV ______________________
14- If I brush my cat more, then there will be less
fur on my furniture - IV ______________________
- DV ______________________
15Now read the following experiment and identify
the independent and dependent variables
- Elizabeth wanted to test if temperature affected
how fast milk goes bad and curdles. She left milk
in a room temperature closet, a fridge, and a
oven that was turned on low heat. She then
measured how rotten the milk was after 10 days. - IV ____________________________________
- DV ____________________________________
16Operational Definition
- Before beginning the experiment, you must have a
clear operational definition. An operational
definition is a statement that describes how a
particular variable is to be measured or how a
term is to be defined. - For example, how will you determine if the water
is frozen? You might decide to insert a stick in
each container in the beginning of the experiment
. Your operational definition of frozen could be
the time at which the stick can no longer move.
17Review
- In an experiment, there is something that a
scientist is testing they control this -
18Review
- In an experiment, because the scientist is
changing this independent variable, this is going
to change and the scientist will measure that
change -
19Review
- This is an educated guess of what is going to
happen during an experiment the scientist forms
this at the beginning of the experiment.
20Did You Get Them Right?
- Independent Variable
- Dependent Variable
- Hypothesis
21Constant
- Constant something that scientist makes sure is
the same throughout the experiment. - Ex. Watering the plants the same amount of water
or making sure you are testing the same person
every time.
22Control
- Control The part of the experiment that the
scientist doesnt change or add the variable to. - Ex. The plant with the white light.
23Materials
- Before beginning the experiment, make a list of
all the materials you will need to complete it.
24Observations
- You perform the experiment see what happens.
You may need to take measurements, pictures etc.
depending on the nature of the experiment.
25Observation
- What is an observation?
- Using your five senses to take note of and
observe your surroundings - Lets go over examples!
26Inference
- An inference is when you make an assumption or
prediction about something that you observe - After you make an observation, you usually make
an inference about what is going on
27Lets practice making inferences!
- The next three slides show some fossil imprints
that were found during a archeological dig. Were
going to record some observations and then make
some inferences about what may have happened
millions of years ago.
28(No Transcript)
29(No Transcript)
30(No Transcript)
31What do you think happened?
32Data
- The observations measurements you make in an
experiment are called data. You gather that data
and organize it into tables, charts or graphs.
Then think through what the data reveals. Does
it support your hypothesis?
33Types of Data
- Quantitative Data Involves measurements or
numbers. This data is organized into graphs
(bar, line, etc.)
- Qualitative Data Involves descriptions or words.
This data is organized into tables or pictures.
34Axes of a Graph
- X-axis (horizontal axis)
- Horizontal means
- Y-axis (vertical axis)
- Vertical means
35Label the x and y axes
36Label the x and y axes
Y-Axis Dependent Variable
X-Axis (Independent Variable)
37Scale
- Now you need to select evenly spaced intervals
that include all your data (a scale). - Data set 1 15, 30, 45, 7, 64. 96
- Minimum value for scale____
- Maximum Value for scale____
38Intervals
- Now you need to select evenly spaced intervals
that include all your data (a scale). - Data set 1 15, 30, 45, 7, 64. 96
- Minimum value for scale__7_
- Maximum Value for scale_96_
39Title_____________________
Money
Student Number
40Title_____________________
Money
Student Number
41Remember TAILS
- T Title
- A Axis (Draw the X Y Axis)
- I Intervals (Pick an interval for your data
numbers) - L Label each axis
- S Scale should take up a page or half a page
(never tiny).
42Drawing a Conclusion
- A conclusion is a statement that sums up what you
have learned from an experiment. You need to
decide whether the data you collected supports
your hypothesis or not. You should repeat an
experiment several times before you can draw any
conclusions from it.
43Repeating the Work
- Before the conclusion of can be accepted by the
scientific community, other scientists must
repeat the experiment check the results. - So when a scientist writes a report, it must be
detailed enough so that scientists around the
world can repeat the experiment for themselves.
44Find Flaws in this Experiment.
- Gerard wants to find out if egg yolk causes
silver to tarnish. He labels 2 silver spoons A
B. He puts egg yolk on both spoons. Then he
places spoon A in a closed container and leaves
spoon B out in the open air. He checks the
spoons over the next few days. - Flaws Egg yolk, which is suppose to be the
variable, should not be put on both spoons.
Other factors, such as the exposure to air,
should be kept the same for both spoons.
45Find Flaws in this Experiment.
- Daria wants to find out if fertilizer causes
plants to grow taller. She takes 2 plant shoots
of the same size type and labels them A B.
She adds fertilizer to plant A but not to plant
B. Then she places plant A in a sunny window and
waters it everyday. She places plant B on a
bookshelf away from the sun and waters it every
other day. - Flaws The experiment has too many variables.
Daria has varied the amount of light and water
each plant receives. Except for fertilizer, all
other conditions should be kept the same.
46Problem Solving
- Hypothesis Turtle eggs develop into male turtles
in cold temperatures and into female turtles in
warm temperatures. - Predict whether this hypothesis is fact or
fiction. Design a simple experiment to show if
the hypothesis is or is not correct. Make sure
your experiment has an experimental setup and a
control setup.
47Practice Drawing a Conclusion
- Here is one way a biologist might design the
experiment. A great quantity of the same type of
turtle eggs are collected. Batches of 25 eggs
are out in containers at different temperatures.
After 60 days, the following data is recorded
Temp. Male Female
26C 21 2
28C 13 11
30C 1 19
32C 1 20