Unit 1 Test Review - Controlled experiments

Unit 1 Test Review

Controlled Experiments

Science Safety (in class)

• Always follow directions (Golden Rule of Science)

• Enter the lab only with permission

• Be respectful of the space and each other

• No drinking or eating in the lab (water okay)

• Read all directions before beginning

• In case of an accident... NOTIFY YOUR TEACHER IMMEDIATLY

Science Safety (at home)

• Always follow directions (Golden Rule)

• Establish a point person

• Protect your electronics

Observations & Inferences

• An observation is a statement describing a fact.

• There are qualitative and quantitative observations.

• An inference is a logical interpretation of an event based on observations and prior knowledge.

Multiple Choice

What is a quantitative observation about the object in this picture?

• the object has round “eyes”

• the object is 4.71 cm tall

• the object is gray

• the object is a toy

Multiple Select

A measurement is a repeatable observation of a quantity. A measurement includes what? (choose all that apply)

• number

• unit

• decimal point

• uncertainty

Multiple Choice

What is the measurement of the volume of liquid in the graduated cylinder?

• 6 mL

• 6.4 mL

• 6.44 mL

• 6.444 mL

Multiple Choice

What SI units are used to measure mass?

• meters

• liters

• grams

• celcius

Controlled Experiments

• Independent variable (IV) - This is the variable that is directly changed by the experimenter

• Dependent variable (DV) - a measured quantity, potentially changing as a result of the IV

• Control variables (CVs) - fixed variables or constants; factors not being tested; kept constant so experiment focuses on the IV

Controlled Experiments continued...

• Experimental Groups - each different group that is part of the IV

• Control Group - Group in which the IV is removed to provide a baseline or point of comparison. Not all experiments have an control group

• Control Variables and the Control Group are different but often mixed up!

Multiple Choice

The independent variable is the

• one you measure.
• one you change.

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

The flavor of ice cream is the ___________ variable.

• independent

• dependent

Multiple Choice

A student wants to test how different amounts of UV light affect the growth of the bacteria, Staphylococcus aureus. She wants to grow the bacteria in petri dishes for her experiment. Which of the following variables should NOT be held constant in this experiment?

• amount of UV light bacteria is exposed to

• amount of time to grow bacteria

• location of petri dishes while growing bacteria

• type of bacteria (Staphylococcus aureus)

Accuracy & Precision

• Accuracy: how close a measurement is to the actual value

• Accuracy is determined by finding the average measurement and comparing that average to the actual value

• Data set precision: how close a set of measurements are to one another

• Data set precision is determined by finding the range (highest to lowest value) in data. (can also use standard deviation & error bars)

• Tool precision: how finely divided a measuring device is (how small the increments are)

• Tool precision determined by the quality of the measuring device… the smaller the divisions, the more certain digits there are

Multiple Choice

This bullseye demonstrates...

• High Accuracy & High Precision

• High Accuracy & Low Precision

• Low Accuracy & High Precision

• Low Accuracy & Low Precision

Multiple Choice

The actual height of the object is 3.56 cm.

Is this data set accurate?

• yes

• no

• can't determine

Tables & Graphs

Enough said?

Open Ended

What is wrong with this table?

Multiple Choice

What type of graph should be used for this data? (remember continuous and categorical variables?!)

• pie chart

• bar graph

• XY scatter plot

• Multi XY scatter plot

Multiple Choice

What type of graph should be used for this data? (remember continuous and categorical variables?!)

• pie chart

• bar graph

• XY scatter plot

• Multi XY scatter plot

Multiple Choice

What type of graph should be used for this data? (remember continuous and categorical variables?!)

• pie chart

• bar graph

• XY scatter plot

• Multi XY scatter plot

Multiple Choice

What is the technique called if a scientist was to use this graph to estimate the height of an 8.7 year old human child?

• trend line

• line of best fit

• interpolation

• extrapolation

Interpreting Results

Discussing errors & assumptions. Analyzing data.

Open Ended

Explain this cartoon to someone that doesn't know anything about error bars.

Multiple Select

Scientific assumptions might be (check all that apply):

• a belief that something that was not a control variable did not affect the results

• thinking that the controlled variables were correctly controlled

• the expected results

• the opinion that the same procedure was followed for all measurements

• a known error

Open Ended

Joey is performing an experiment where they make cupcakes with different amounts of flour. In one batch Joey uses two, 1/2 cups to measure the flour, in another batch they use four, 1/4 cups to measure the flour. Is this an error?

Multiple Choice

A scientist would conclude that a warm glow stick would conclusively glow longer than a hot glow stick.

• True

• False

Hypothesis

• a prediction based on background knowledge

• an educated guess suggesting an answer to a problem or set of observations

• If…then…because… (citation).

• If (choose an experimental group), then (predict the DV), because (research) (citation).

Multiple Choice

After the 'If' in a hypothesis,

• choose an experimental group to make a prediction about

• predict the dependent variable (maximum or minimum)

• use scientific research to support the prediction

• Use the first part of the full citation to create the in-text citation

Multiple Choice

After the 'then' in a hypothesis,

• choose an experimental group to make a prediction about

• predict the dependent variable (maximum or minimum)

• use scientific research to support the prediction

• Use the first part of the full citation to create the in-text citation

Multiple Choice

After the 'because' in a hypothesis,

• choose an experimental group to make a prediction about

• predict the dependent variable (maximum or minimum)

• use scientific research to support the prediction

• Use the first part of the full citation to create the in-text citation

Valid Scientific Experiments

https://youtu.be/CJfdUy4LwfQ.

(I can't embed this link but you can copy/paste into your web browser to view)

End of review slides

This slide show is just ONE way to prepare for the test. It in no way encompasses all the information that will be on the test, you still need to review your notes, activities, homeworks, quizzes, etc. GOOD L