Nature of Science

Nature of ScienceNature of Science

Science Science

Facts and ideas developed by scientists and the methods used by scientists to gain information.

A process of making observations and asking questions about those observations.

Scientists gain knowledge through study and investigation.

Facts and ideas developed by scientists and the methods used by scientists to gain information.

A process of making observations and asking questions about those observations.

Scientists gain knowledge through study and investigation.

ObservationsObservationsData

recorded observations or any information acquired through experimentation

Types of Observations Qualitative

involves a description of the quality by using your senses

Quantitative involves the use of instruments; results are

measureable; must include a number

Data recorded observations or any information acquired through experimentation

Types of Observations Qualitative

involves a description of the quality by using your senses

Quantitative involves the use of instruments; results are

measureable; must include a number

Quantitative or Qualitative ?

Quantitative or Qualitative ?

1. It is about _____ centimeters in diameter.

2. The flame begins about 1-cm above the top of the candle.

3. The flame is a shade of blue at its base.

4. The length decreased during the observation period.

5. Immediately around the wick in a region about 1-cm wide andextending about 1-cm above the top of the wick, the flame is dark.

6. The amount of decrease was about _____ centimeters per half hour.

7. This dark region is roughly conical in shape.

8. The candle is translucent.

9. It is white (or yellow, etc.).

10. The flame has sharply defined sides but a ragged top.

1. It is about _____ centimeters in diameter.

2. The flame begins about 1-cm above the top of the candle.

3. The flame is a shade of blue at its base.

4. The length decreased during the observation period.

5. Immediately around the wick in a region about 1-cm wide andextending about 1-cm above the top of the wick, the flame is dark.

6. The amount of decrease was about _____ centimeters per half hour.

7. This dark region is roughly conical in shape.

8. The candle is translucent.

9. It is white (or yellow, etc.).

10. The flame has sharply defined sides but a ragged top.

Scientific Method

Series of steps used to answer questions and solve problems

Traditional Steps of the Scientific Method

Identify the problem

Gather information

Make a hypothesis

Test the hypothesis by experimentation

Observe, Record Observations (Data)

Conclusion

Scientific Method

Series of steps used to answer questions and solve problems

Traditional Steps of the Scientific Method

Identify the problem

Gather information

Make a hypothesis

Test the hypothesis by experimentation

Observe, Record Observations (Data)

Conclusion

Scientific Investigation Scientific Investigation

Scientific InvestigationScientific Investigation

Scientific investigations do not always proceed from

one step of the scientific method to the next.

Sometimes steps are

skipped

and sometimes they are

repeated.

Scientific investigations do not always proceed from

one step of the scientific method to the next.

Sometimes steps are

skipped

and sometimes they are

repeated.

Experimental DesignExperimental Design

Variable• a factor; item in an experiment which when changed causes the results of the experiment to change

Independent variable

factor that is purposefully changed by the experimenter Dependent variable

factor that responds, therefore it is what is measured Controlled variable

constant; factor(s) that are kept the same

throughout the experiment

Variable• a factor; item in an experiment which when changed causes the results of the experiment to change

Independent variable

factor that is purposefully changed by the experimenter Dependent variable

factor that responds, therefore it is what is measured Controlled variable

constant; factor(s) that are kept the same

throughout the experiment

Experimental Design Experimental Design Testing Groups

Experimental Group

the test group where all conditions, except the independent variable,are kept the same

Control Group

the test group that is used as a standard for comparison; doesn’t include the independent variable

Sam wished to investigate how fertilizer run-off affects the growth of algae in freshwater lakes and streams. He set his experiment up in this way. He placed 900 mL of water into each of five 1000 mL glass beakers. To each beaker he added 5 mL of water from an aquarium which contained a large concentration of algae. The beakers were placed under a grow light which was timed to provide 12 hours of light each day. Liquid fertilizer was added to the beakers in the following amounts: beaker 1 – no fertilizer, beaker 2 – 2 mL of fertilizer, beaker 3 – 4 mL of fertilizer, beaker 4 – 6 mL of fertilizer, beaker 5 – 8 mL of fertilizer. Each week a random sample from each of the beakers was examined under a microscope to get a count of the number of algae cells present.

Sam wished to investigate how fertilizer run-off affects the growth of algae in freshwater lakes and streams. He set his experiment up in this way. He placed 900 mL of water into each of five 1000 mL glass beakers. To each beaker he added 5 mL of water from an aquarium which contained a large concentration of algae. The beakers were placed under a grow light which was timed to provide 12 hours of light each day. Liquid fertilizer was added to the beakers in the following amounts: beaker 1 – no fertilizer, beaker 2 – 2 mL of fertilizer, beaker 3 – 4 mL of fertilizer, beaker 4 – 6 mL of fertilizer, beaker 5 – 8 mL of fertilizer. Each week a random sample from each of the beakers was examined under a microscope to get a count of the number of algae cells present.

ExampleExample

Dependent Variable number of algae cells

Independent Variableamount of fertilizer

Experimental Groupbeakers with fertilizer

(beakers #2-5)

Control Groupbeaker without fertilizer

( beaker #1)

Controlled Variables 900 mL of water 5 mL of aquarium water grow light for 12 hours 1000 mL glass beakers

Dependent Variable number of algae cells

Independent Variableamount of fertilizer

Experimental Groupbeakers with fertilizer

(beakers #2-5)

Control Groupbeaker without fertilizer

( beaker #1)

Controlled Variables 900 mL of water 5 mL of aquarium water grow light for 12 hours 1000 mL glass beakers

Stephanie conducted an experiment to determine if the color of a maze would affect the time it took for a mouse to run through it. She constructed 5 identical mazes of plywood. She painted them white, yellow, red, blue and green. She purchased 10 young mice at a local pet store. She ran 2 mice through each maze until the mice could run it twice without making an error, she then compare the number of runs it took the mice in each color to learn it

Stephanie conducted an experiment to determine if the color of a maze would affect the time it took for a mouse to run through it. She constructed 5 identical mazes of plywood. She painted them white, yellow, red, blue and green. She purchased 10 young mice at a local pet store. She ran 2 mice through each maze until the mice could run it twice without making an error, she then compare the number of runs it took the mice in each color to learn it

ExampleExample

Dependent Variable

number of runs to learn maze

Independent Variablecolor of maze

Experimental Groupmice running in

colored maze

Control Groupmice running in

white maze

Controlled Variables age of mice maze design

Dependent Variable

number of runs to learn maze

Independent Variablecolor of maze

Experimental Groupmice running in

colored maze

Control Groupmice running in

white maze

Controlled Variables age of mice maze design

Researches want to determine the best temperature for storing batteries. Describe the following variables you need to consider when

performing the experiment.

Independent VariableStorage Temperature

Dependent Variablehours of use after storage

2 Controlled Variablessame type of batterysame expiration datesame moisture (environment)

Researches want to determine the best temperature for storing batteries. Describe the following variables you need to consider when

performing the experiment.

Independent VariableStorage Temperature

Dependent Variablehours of use after storage

2 Controlled Variablessame type of batterysame expiration datesame moisture (environment)

ExampleExample

ExampleExample

Your friend has to plan an experiment for a science fair. He asks for your help.His topic is “ The Strongest Cloth for Backpacks”.

Describe the following variables you need to consider when performing the

experiment.

Independent Variabletype of fabric

Dependent Variablehow long fabric can carry heavy load without

tearing

3 Controlled Variablessize of fabricinitial condition of the fabricload used

Your friend has to plan an experiment for a science fair. He asks for your help.His topic is “ The Strongest Cloth for Backpacks”.

Describe the following variables you need to consider when performing the

experiment.

Independent Variabletype of fabric

Dependent Variablehow long fabric can carry heavy load without

tearing

3 Controlled Variablessize of fabricinitial condition of the fabricload used

ExampleExample

Larry was told that a certain muscle cream was the newest thing onthe market and claims to double a person’s muscle power when used as part of a muscle-building workout. Interested in this product, he buys the special muscle cream and recruits Patrick andSpongeBob to help him with an experiment. Larry develops a specal marshmellow weight-lifting program forPatrick and SpongeBob. He meets with them once every day for a period of 2 weeks and keeps track of their results. Before each session Patrick’s arms and back are lathered in the muscle cream, while SpongeBob’s arms and back are lathered with the regular lotion.

Larry was told that a certain muscle cream was the newest thing onthe market and claims to double a person’s muscle power when used as part of a muscle-building workout. Interested in this product, he buys the special muscle cream and recruits Patrick andSpongeBob to help him with an experiment. Larry develops a specal marshmellow weight-lifting program forPatrick and SpongeBob. He meets with them once every day for a period of 2 weeks and keeps track of their results. Before each session Patrick’s arms and back are lathered in the muscle cream, while SpongeBob’s arms and back are lathered with the regular lotion.

Control Group

SpongeBob

Independent VariableMuscle Cream

Dependent VariableAmount of Marshmellows lifted ( Strength)

Controlled VariablesSame amount of creamCream applied to same area

ConclusionSince both improved their results, it doesn’t appear that the claims for the special cream are true. If cliams were correct, twe should have seen Particks a mont double, but not SpongeBob’s. Improvement were likely due to the workout itself and not the cream

Control Group

SpongeBob

Independent VariableMuscle Cream

Dependent VariableAmount of Marshmellows lifted ( Strength)

Controlled VariablesSame amount of creamCream applied to same area

ConclusionSince both improved their results, it doesn’t appear that the claims for the special cream are true. If cliams were correct, twe should have seen Particks a mont double, but not SpongeBob’s. Improvement were likely due to the workout itself and not the cream

TimePatrick

SpongeBob

Initial Amt.

18 5

After 1 Wk

24 9

After 2 Wks

33 17

Scientific ModelsScientific Models

representation of an object or system that make concepts easier to understand

can represent things to small to see or too large to observe directly

can be used to test hypothesis and illustrate theories

representation of an object or system that make concepts easier to understand

can represent things to small to see or too large to observe directly

can be used to test hypothesis and illustrate theories

Science Lab Reports Science Lab Reports

A formal lab report should be typed, have page numbers, and contain all of the following information in the following order. Every student is expected to write his or her own report. You are encouraged to discuss the experiment , analysis and interpretation with your classmates but you are expected to turn in original work. If any portion of your report is plagiarized from another student, book or website, you are guilty of academic misconduct.

Take pride in your work.

A formal lab report should be typed, have page numbers, and contain all of the following information in the following order. Every student is expected to write his or her own report. You are encouraged to discuss the experiment , analysis and interpretation with your classmates but you are expected to turn in original work. If any portion of your report is plagiarized from another student, book or website, you are guilty of academic misconduct.

Take pride in your work.

Title Page title should relate to the basic concept involved in the lab activity

be creative - don’t use your problem statement

graphic relating to lab is required

name, class period and date are required

Problem states very precisely what you want to know written as a question must include independent and dependent variable

Title Page title should relate to the basic concept involved in the lab activity

be creative - don’t use your problem statement

graphic relating to lab is required

name, class period and date are required

Problem states very precisely what you want to know written as a question must include independent and dependent variable



Hypothesis prediction of how your experiment will come out

educated guess based on knowledge & research you have done prior to experiment

expresses relationships between variables

only valid if testable and supported by evidence

written as an “ If……,then……. because…...” statement

Materials list, in columns, all equipment and quantities needed for experiment

Hypothesis prediction of how your experiment will come out

educated guess based on knowledge & research you have done prior to experiment

expresses relationships between variables

only valid if testable and supported by evidence

written as an “ If……,then……. because…...” statement

Materials list, in columns, all equipment and quantities needed for experiment

Procedure logical, numerical listing of each step needed to conduct experiment

needs to be clear and precise so anyone could repeat experiment without difficulty

should include illustrations with labels to help clarify set-up and/or a particular step

good grammar, spelling & communication skills are important

First step should read: Gather materials

Last step should read: Clean up and complete lab report

Data Organized presentation of what you have observed

Quantitative Observations - charts/tables with labels and title(s)

Qualitative Observations - paragraph format and/or photos with captions

Procedure logical, numerical listing of each step needed to conduct experiment

needs to be clear and precise so anyone could repeat experiment without difficulty

should include illustrations with labels to help clarify set-up and/or a particular step

good grammar, spelling & communication skills are important

First step should read: Gather materials

Last step should read: Clean up and complete lab report

Data Organized presentation of what you have observed

Quantitative Observations - charts/tables with labels and title(s)

Qualitative Observations - paragraph format and/or photos with captions


Data Presentation Graphs

Independent Variable: placed on horizontal / “x” axis; given info; purposefully changed factor

Dependent Variable: placed on vertical / “y” axis; info obtained during the experiment; response to independent variable

should accommodate at least 75% of paper

title should include the independent & dependent variable and appear in the upper part of the graph

legends (keys) should be within the body of graph and displayed in a box

axes are labeled with variable and units as follows: variable(units)

consistent intervals used in numbering, or an appropriate sign is used to indicate a break

numbers are neatly written and spaced appropriately and logically

everything (text and numbers), but not actually graph, are done in pen

Data Presentation Graphs

Independent Variable: placed on horizontal / “x” axis; given info; purposefully changed factor

Dependent Variable: placed on vertical / “y” axis; info obtained during the experiment; response to independent variable

should accommodate at least 75% of paper

title should include the independent & dependent variable and appear in the upper part of the graph

legends (keys) should be within the body of graph and displayed in a box

axes are labeled with variable and units as follows: variable(units)

consistent intervals used in numbering, or an appropriate sign is used to indicate a break

numbers are neatly written and spaced appropriately and logically

everything (text and numbers), but not actually graph, are done in pen


Conclusion

Well written, 3 paragraph minimum, which should incorporate any

teacher generated questions, summarizing findings

Paragraph 1: Analysis of Hypothesis restate problem and answer it based on experimental findings state whether hypothesis was supported or rejected present quantitative findings that either support or reject hypothesis

Paragraph 2: Limitations and Weakness of your Procedure evaluate the procedure that you used (equipment, materials, methods) describe possible sources of error and modifications for improvement

Paragraph 3: Interpretations of the Data, Conclusion & Ideas for Further Study

explain patterns and trends in the data

explain results using scientific reasoning & knowledge

describe other experiments or extensions of the lab that you feel would be useful to explore the concept further

Conclusion

Well written, 3 paragraph minimum, which should incorporate any

teacher generated questions, summarizing findings

Paragraph 1: Analysis of Hypothesis restate problem and answer it based on experimental findings state whether hypothesis was supported or rejected present quantitative findings that either support or reject hypothesis

Paragraph 2: Limitations and Weakness of your Procedure evaluate the procedure that you used (equipment, materials, methods) describe possible sources of error and modifications for improvement

Paragraph 3: Interpretations of the Data, Conclusion & Ideas for Further Study

explain patterns and trends in the data

explain results using scientific reasoning & knowledge

describe other experiments or extensions of the lab that you feel would be useful to explore the concept further


Documents

Nature of Science