Scientific MethodScientific Method

Mr. HunterMr. Hunter

What does a scientist look like?What does a scientist look like?

Draw a picture of what Draw a picture of what you think a scientist you think a scientist

looks like.looks like.

www.eepybird.comwww.eepybird.comDo you think this Do you think this represents a true represents a true

scientific experiment? scientific experiment? Why or why not?Why or why not?

Where do I begin?Where do I begin?

The first step is to decide on a topic The first step is to decide on a topic that interests you.that interests you.

QuestionQuestion

Develop an investigative question.Develop an investigative question.

You decide… Which of these are You decide… Which of these are suitable questions for a science fair suitable questions for a science fair

project?project? 1. What does a human heart look like?1. What does a human heart look like? 2. Does the life of a light bulb depend on its wattage?2. Does the life of a light bulb depend on its wattage? 3. What are the three types of volcanoes? Where are 3. What are the three types of volcanoes? Where are

they found?they found? 4. What are the effects of caffeine on the respiratory 4. What are the effects of caffeine on the respiratory

rate of cockroaches?rate of cockroaches? 5. How does wing shape affect the lift of planes?5. How does wing shape affect the lift of planes? 6. What kinds of clouds appear in the sky every day?6. What kinds of clouds appear in the sky every day?

Decide whether or not each question Decide whether or not each question is good for experimentation. Copy is good for experimentation. Copy

only the questions that make a good only the questions that make a good experiment.experiment.

1. What does a cell look like?1. What does a cell look like? 2. Which type of battery lasts the longest?2. Which type of battery lasts the longest? 3. Will mentos or sweet tarts cause diet coke to 3. Will mentos or sweet tarts cause diet coke to

shoot higher?shoot higher? 4. What is the function of the liver?4. What is the function of the liver? 5. Which has more sugar- Eclipse or Trident gum?5. Which has more sugar- Eclipse or Trident gum?

HypothesisHypothesis

An hypothesis is written in the form An hypothesis is written in the form of an if-then sentence. of an if-then sentence.

Example:Example:If amaryllis plants are given more sunlight, If amaryllis plants are given more sunlight,

then they will grow more.then they will grow more.

Write an hypothesis for each of the Write an hypothesis for each of the following questions.following questions.

1. Will eating sugar before a test improve 1. Will eating sugar before a test improve performance?performance?

2. How does acid rain affect plant growth?2. How does acid rain affect plant growth? 3. Does playing music help plants to grow?3. Does playing music help plants to grow? 4. Does soil particle size affect plant growth?4. Does soil particle size affect plant growth? 5. Which type of soap works more effectively 5. Which type of soap works more effectively

to kill bacteria?to kill bacteria?

Decide on VariablesDecide on Variables

Independent Variable:Independent Variable: the variable that the the variable that the scientist changes in the experimentscientist changes in the experiment

Dependent Variable:Dependent Variable: the variable that the variable that changes in response to the independent changes in response to the independent variablevariable

ControlControl: the part of the experiment that does : the part of the experiment that does not changenot change

Decide on the variables/controls.Decide on the variables/controls.

1. Will different colors of light affect a gerbil’s 1. Will different colors of light affect a gerbil’s ability to go through a maze?ability to go through a maze?

2. What is the optimum temperature for yeast 2. What is the optimum temperature for yeast to ferment?to ferment?

3. Will different temperatures affect golf ball 3. Will different temperatures affect golf ball performance?performance?

4. At what age do fruitflies best mate?4. At what age do fruitflies best mate?

Choose the topics appropriate for scientific study Choose the topics appropriate for scientific study and write a hypothesis, variables, and control for and write a hypothesis, variables, and control for

each.each. 1. What are the effects of different voltages of electric 1. What are the effects of different voltages of electric

currents on germinating seeds?currents on germinating seeds? 2. What are the functions of the Environmental 2. What are the functions of the Environmental

Protection Agency?Protection Agency? 3. What is the relationship between test performance 3. What is the relationship between test performance

and being left-handed or right-handed?and being left-handed or right-handed? 4. Why can you see the moon during the day?4. Why can you see the moon during the day? 5. What happens during solar and lunar eclipses?5. What happens during solar and lunar eclipses?

Writing a ProcedureWriting a Procedure

1. The procedure 1. The procedure should be _______ should be _______ and written well and written well enough so that enough so that someone else someone else could perform the could perform the experiment.experiment.

ProcedureProcedure

2. Include units of amounts. 2. Include units of amounts.

3. The first word of 3. The first word of almost almost every every step should be a verb. step should be a verb.

1. Pour one packet of activated dry yeast into each Ziploc 1. Pour one packet of activated dry yeast into each Ziploc bag. bag.

2. Add 1 teaspoon of sugar to one of the bags and label the 2. Add 1 teaspoon of sugar to one of the bags and label the bag 1 tsp.bag 1 tsp.

3. Add ½ teaspoon of sugar to another bag and label it as ½ 3. Add ½ teaspoon of sugar to another bag and label it as ½ tsp.tsp.

4. Add ¼ teaspoon of sugar to the fourth bag and label it as 4. Add ¼ teaspoon of sugar to the fourth bag and label it as ¼ tsp.¼ tsp.

5. Mark 0 on the outside of the last bag and do not add any 5. Mark 0 on the outside of the last bag and do not add any sugar to itsugar to it

6. Pour warm water into the large bowl so it is about 2/3 6. Pour warm water into the large bowl so it is about 2/3 full. Check the temperature of the water with the full. Check the temperature of the water with the thermometer. The water should be about 46oC (115oF). thermometer. The water should be about 46oC (115oF). Add hot or cold water to bring the water to this temperature.Add hot or cold water to bring the water to this temperature.

7. Use the measuring cup to dip ¼ cup of warm water from the bowl 7. Use the measuring cup to dip ¼ cup of warm water from the bowl into each of the bags. Gently squeeze each bag between your fingers into each of the bags. Gently squeeze each bag between your fingers to mix the contents thoroughly. Make sure that there are no dry to mix the contents thoroughly. Make sure that there are no dry pockets of yeast or sugar in the bags.pockets of yeast or sugar in the bags.

8. Squeeze most of the air out of the bags and seal them. Set the bags 8. Squeeze most of the air out of the bags and seal them. Set the bags in the bowl of warm water in a warm place so it will not cool down in the bowl of warm water in a warm place so it will not cool down rapidly.rapidly.

9. Wait 30 - 40 minutes.9. Wait 30 - 40 minutes.

10. Take the bag marked 0 out of the water, dry it, and place it on a 10. Take the bag marked 0 out of the water, dry it, and place it on a flat table. Put the cardboard or notebook on top of the bag, holding the flat table. Put the cardboard or notebook on top of the bag, holding the tablet level. Use the ruler to measure the distance from the table to the tablet level. Use the ruler to measure the distance from the table to the bottom of the cardboard.bottom of the cardboard.

11. Record your measurements.11. Record your measurements.

12. Repeat #10 with the remaining bags.12. Repeat #10 with the remaining bags.

13. Calculate the approximate volume of carbon dioxide in each bag: 13. Calculate the approximate volume of carbon dioxide in each bag: measure the length of the bag (a); measure the width of the bag (b); measure the length of the bag (a); measure the width of the bag (b); distance from table to cardboard (c). a x b x c will give you the distance from table to cardboard (c). a x b x c will give you the volume in each bag.volume in each bag.

Write these directions like they should be Write these directions like they should be written for a scientific procedure.written for a scientific procedure.

1. Add peanut butter to bread. 1. Add peanut butter to bread. 2. Add jelly to bread.2. Add jelly to bread. 3. The breads should then go together.3. The breads should then go together. 4. You have a sandwich4. You have a sandwich

Clothespin ExperimentClothespin Experiment

Which thumb muscle is the Which thumb muscle is the strongest?strongest?

HypothesisHypothesis : : If If we open/close a clothespin in we open/close a clothespin in both hands, both hands, thenthen the _____ will be able to the _____ will be able to

open/close it more times since it is the open/close it more times since it is the strongest muscle.strongest muscle.

Independent Variable:Independent Variable: the hand the hand

Dependent Variable:Dependent Variable: the strength of the muscle the strength of the muscle

ControlControl

A A control control is something that stays the _____ is something that stays the _____ throughoutthroughout the experiment. the experiment.

ProcedureProcedure

1. 1. Open and closeOpen and close clothespin in clothespin in rightright hand for hand for one minuteone minute. Count . Count and the number of times you open and the number of times you open and close it. Record data and close it. Record data Complete two additional trials. Complete two additional trials.

2. Repeat step 1 for left hand. 2. Repeat step 1 for left hand.

DataData

Data is information in numerical Data is information in numerical form usually displayed as a _____, form usually displayed as a _____, table, or _____ .table, or _____ .

DataData

TrialTrial Right Hand (# of Right Hand (# of times)times)

Left Hand (# of Left Hand (# of times)times)

11

22

33

Drawing ConclusionsDrawing Conclusions

You must _____ data to determine if You must _____ data to determine if your results supported your your results supported your

hypothesis. hypothesis.

If your results do not If your results do not support your support your

hypothesis, then you hypothesis, then you must make a new one must make a new one or carry out further or carry out further

observations or observations or experiments.experiments.

How can we represent this How can we represent this information in a graph?information in a graph?

0

20

40

60

80

100

Number of Times

Opened/Closed

R T1 L T1 R T2 L T2 R T3 L T3

Right-Handed/Left-Handed Trials

Clothespin Lab Data

right

left

YearYear Atmospheric Carbon Atmospheric Carbon Dioxide (Dioxide (ppmppm))

18801880 260260

19001900 290290

19201920 300300

19401940 318318

19601960 340340

19801980 360360

200200 700700

Create a line graph using the data on Create a line graph using the data on atmospheric carbon dioxide.atmospheric carbon dioxide.

1. Has the amount of carbon dioxide in the 1. Has the amount of carbon dioxide in the atmosphere increased or decreased since 1880?atmosphere increased or decreased since 1880?

2. The line on the graph is curved. What does this 2. The line on the graph is curved. What does this curve indicate?curve indicate?

3. Was the rate of change in the level of carbon 3. Was the rate of change in the level of carbon dioxide between 1940 and 1960 higher or lower dioxide between 1940 and 1960 higher or lower than it was between 1860 and 1900? How can than it was between 1860 and 1900? How can you tell?you tell?

4. What conclusions can you draw from this data?4. What conclusions can you draw from this data?

Atmospheric Carbon Dioxide Data

0100200300400500600700800

1 2 3 4 5 6 7 8

Year

Atm

osp

her

ic C

arb

on

D

ioxi

de

Series1

Weight Weight Held (lbs.) Held (lbs.)

Trial 1Trial 1

Weight Weight Held (lbs.) Held (lbs.)

Trial 2Trial 2

Weight Weight Held (lbs.) Held (lbs.)

Trial 3Trial 3

GladGlad 2020 3030 2828

Great ValueGreat Value 7070 8989 9696

HeftyHefty 3030 5050 4040