Designing a Lab

Standard 1: Design and conduct scientific investigations using appropriate

vocabulary, tools, and techniques.

Steps of the Scientific Method

1. Choose a PROBLEM2. RESEARCH the problem3. Develop a HYPOTHESIS4. Write a PROCEDURE5. Perform the EXPERIMENT6. Analyze the DATA7. State the CONCLUSIONS

The Question • is specific to your investigation, and must be answered

by measuring. • The question includes the Independent and Dependent

variables

The Test of a good question Is it Objective and Quantitative?

► Objective = Based on Facts

Example: The Fastest Class

► Quantitative = Uses a Quantity

Example: The Largest Class

► Qualitative = Uses a Quality

Example: The Best Class

► Subjective = Based on Opinions

Example: The Most

Creative Class

Examples For Questions:– The grass is not growing in certain parts of the field.

• Is the amount of light affecting how high the grass grows?– All paper towels are the same.

• Does one type of paper towel pick up more water then the other?– The Red Sox are not winning games

• Would the Red Sox win more games then the Yankees if they had the same payroll?

Variable

Any factor that could affect the outcome of the experiment

Types of Variables• Independent Variable (IV)-

Variable that is being tested/Investigated“I Changed _________”

• Dependent Variable (DV)Variable that changes in response

to the experiment“Data collected was __________”

• Constants-Variables that are kept the same throughout the experiment

Independent Variable (IV)

Variable that is being tested“I Changed _________”

Examples from Warp Speed:-Changing the order of the people, -Changing the shape people were in,-Changing the way the ball was past

Dependent Variable (DV)

Variable that changes in responseto the experiment

“Data collected was __________”

Example from Warp Speed:-Time it took the ball to get through the order

Constants

Variables that are kept the same throughout the experiement

• Examples from Warp Speed:– Same order– Same ball– Same rules

Hypothesis

• Hypothesis is a possible explanation, a preliminary conclusion, or an educated guess at the solution.

• The hypothesis is an answer to “the question”• Hypothesis is based on what you’ve learned from

your research or prior knowledge (Basis)

Hypothesis is stated in an “if … then…” Statement. (NEVER use “I think”)

If Independent Variable, then Dependent Variable.

If something specific is done, then what will the measureable results be.

If the cause, then the effect.

Examples:– The grass is not growing in certain parts of the

field.• Is the amount of light affecting how high the grass

grows?– If the grass receives more light, then it will grow higher

–All paper towels are the same.• Do thicker paper towels pick up more water

than thinner ones?– If the paper towel is thicker, then it will pick up

more water.

– The Red Sox are not winning games• Would the Red Sox win more games than the

Yankees if they had the same payroll? – If the Red Sox had the same payroll as the Yankees,

then they would win more games.

Basis• 2-3 Sentences that support your hypothesis• The basis is the background knowledge or research that

supports the hypothesis:(why you think the results will be

what your hypothesis predicts)

–The grass is not growing in certain parts of the field.• Is the amount of light affecting how high

the grass grows?– If the grass receives more light, then it will

grow higher. This is because plants need light to grow. If plants do not receive light they cannot grow. In areas of the field where the grass receives more light the grass will grow higher.

–All paper towels are the same.• Does one type of paper towel pick up

more water then the other?– If the paper towel is thicker, then it will pick

up more water. The thicker the paper towel the more space there will be to hold water molecules. If a paper towel has more space in it be able to hold water.

Design the Experiment• Write the Methods: – a list of clear and specific steps to your experiment– includes a specific materials list.

• Your procedure should:– Test only one variable at a time– Maintain constants– Use more than one trial (Ideally 3 or more)• When you repeat the exact same steps of the procedure

multiple times

– Include a control group to compare your results

Experimental Group(s)Group(s)/Trial(s) that

tests the Independent

variable

(with the “change”)

Control Group A Group or set of Trials that

do not include the Independent Variable

Used to determine the affects of the

independent variable

(no “change”, normal conditions)

VOCABULARYSubjective-

Objective-

Quantitative-

Qualitative-

Observation-

Inference-

Basis-

Trial-

Variable-

Constants-

Control-