Experimental Design Diagram

Experimental Design Diagram

How can I make sure the experiments I do are accurate and fair

What is Good Experimental Design?

• ‌Experimental Design is a logical, consistent process

• It uses the SCIENTIFIC METHOD for stating, solving, and understanding problems in the natural world.

Why Perform Experiments?

• The goal of all experiments is to test ideas or hypotheses, to solve or understand phenomena in nature.

• This is all done to either create a new theory, or to add more evidence to support an existing theory

Multiple Choice

An experiment tests how one _________ is affected by another.

• Variable

• test

• scientist

• option

Multiple Choice

The more times that an experiment is repeated and the same results obtained, the more likely the results are _________.

• better

• observed

• valid/accurate

• used

Multiple Choice

A(n) ____________ is a scientific investigation that is performed under controlled conditions.

• experiment

• lab

• inquiry

• hypothesis

What's the process?

• ‌OBSERVE Something

• Research or Infer to formulate a Hypothesis

• Design a Procedure to test that hypothesis

• Conduct an experiment and record data

• Analyze the Results

• Draw a Conclusion and communicate the results

Multiple Choice

What part of the scientific method/experimental design is this: Rene grew mouth bacteria in a medium in the lab.  She placed drops of different mouthwashes on bacteria on each plate.

• recognize a problem
• test the hypothesis with an experiment
• form a hypothesis   
• draw conclusions

Multiple Choice

What part of the scientific method/experimental design is this: Jonathan’s data showed that household cockroaches moved away from raw cucumber slices.

• recognize a problem
• test the hypothesis with an experiment
• form a hypothesis
• draw conclusions

Multiple Choice

What part of the scientific method/experimental design is this: Susan said, “If I fertilize my geranium plants, then they will blossom faster.”

• recognize a problem

• test the hypothesis with an experiment

• form a hypothesis

• draw conclusions

Multiple Choice

What part of the scientific method/experimental design is this: Stephen predicted that seeds would start to grow faster if an electric current traveled through the soil in which they were planted.

• recognize a problem
• test the hypothesis with an experiment
• form a hypothesis
• draw conclusions  

Observations

• There are two types of observations:

• Qualitative Observations: These are made by ‌acquiring information using your senses or with special equipment.

• Quantitative Observations: ‌is acquiring and recording numerical data.

​Observations lead to inferences...

• ​An inference comes AFTER making qualitative and quantitative observations.

• ​Inferences are like an educated guess that is made BECAUSE of the observations you made.

Multiple Choice

What can you infer from the observation? The apple has a missing chunk.

• Someone took a bite of the apple

• The apple fell from a tree onto the road.

• A worm was inside the apple.

Multiple Choice

What can you infer from the observation? The girl is dressed in shorts and a jersey and is holding a basketball.

• The girl is on the basketball team.

• The girl is going for a walk.

• The girl is a swimmer.

What's the Problem?

• ‌Careful observations lead to questions…

• A Problem Statement is a question that compares two variables.

• Example 1: What is the effect of thechange in the length of daylight on the leaf color of deciduous trees?

Multiple Choice

What part of the scientific method/experimental design is this: Jose saw bats catching insects after dark. He asked, “How do bats find insects in the dark?”

• ask a question

• test the hypothesis with an experiment

• form a hypothesis

• draw conclusions

Multiple Choice

What part of the scientific method/experimental design is this: Dana wants to know how different are synthetic fibers from natural fibers.

• recognize a problem

• test the hypothesis with an experiment

• form a hypothesis

• draw conclusions

What are variables?

• ‌A Variable is anything that changes.

• The variables compared in the problem statement are the INDEPENDENT & DEPENDENT variables.

• The IV iswhat is changed at the beginning of the experiment.

• The DV is what changes BECAUSE of the IV

IV vs. DV

• ‌INDEPENDENT VARIABLE:

• ‌A variable YOU MANIPULATE or CHANGE at the BEGINNING of the experiment.

• The different variations of the IV are called the LEVELS of the IV.

• DEPENDENT VARIABLE:

• The Variable that changes as a result of the independent variable.

• The Variable that is measured and recorded.

Constants & Control

• IN ANY EXPERIMENT, YOU MUST CONTROL AS MUCH AS POSSIBLE.

• ‌Constants are variables that DO NOT CHANGE through the entire experiment. It is something that MUST REMAIN THE SAME!

• The Control is one of the levels of the IV.

• It is the group that is used TO COMPARE TO THE RESULTS FOR EACH LEVEL OF THE IV. 

Multiple Choice

A scientist is testing the impact of light and dark on the moth behavior by turning a light on and off. The DEPENDENT variable is...

• amount of light

• moth behavior/their reaction

• number of moths

Multiple Choice

Diego wants to know how drinking milk affects how tall Dora grows. Which is the independent variable?

• Drinking milk.

• Diego's growth.

• Dora's growth.

• Chocolate or plain milk.

Multiple Choice

What is the INDEPENDENT variable (cause)in this experiment?

"Which type of metal, copper or aluminum, conducts heat faster?"

• size of metal

• types of metal

• time it takes to heat up

• shape of the metal

Multiple Choice

What is the DEPENDENT variable (effect) in this experiment?

"Does eating breakfast improve test score?"

• eating breakfast or not

• the grade you got on the test

• what time you get up in the morning

• what you eat for breakfast

Multiple Choice

The variable the is changed on purpose is..

• Constant

• Control

• Independent Variable

• Dependent Variable

Multiple Choice

Experiment: How does watching TV during studying affect a student’s test grades?

The students grades are the ___________ variable.

• independent
• dependent

Multiple Choice

Experiment: Do roses grow more in height in partial or direct sunlight?
The growth height is the ____________  variable.

• independent
• dependent

Multiple Choice

Experiment: Does changing the wing shape to make it more narrow affect the distance a paper airplane will fly?

The wing shape is the ___________ variable.

• independent

• dependent

Multiple Choice

Experiment: How does the flavor of ice cream affect the speed of melting?

The flavor of ice cream is the ___________ variable.

• independent

• dependent