3. Mass/ Weight:

a) How to find mass:

place an object on a scale

1. scale:

digital scale or

triple beam balance

2. looks like:

b) measurements are in:

grams

1. English:

pounds (lbs)

2. Metric:

grams (g) & kilograms (kg)

Experimental Design

Unit 1 - Science 7

**SCIENCE**

**7**

I. Scientific Methods - many different ways for discovery, but they all use observation, logic, evidence, and analysis.

Jot this

chart down

IMPORTANT TERM

Observation: the gaining of knowledge using the five senses (taste, touch, hear, feel, see)

Observation: the animal has feathers

NOT AN OBSERVATION: the animal flies

Experiment question: specific question that can be answered scientifically

Example: What are the effects of bleach on worms?

Non-example: How do the worms feel about bleach?

Vague question: What happens to worms affected by stuff?

Hypothesis: a prediction based on an observation and fact that can be tested

IT IS NOT A GUESS!!!

Testing and Observations

Once you have

gathered some

data, researched

your topic and come up with a hypothesis, it is time to test and make more observations.

But observation isn't always easy.

Analyze: to examine carefully and in detail for purposes of explanation and understanding

Evidence: observations, data, facts, measurements

Inference: your opinions or guesses that are based on the facts and evidence

Conclusion: what the data, inferences, and evidences mean to your hypothesis

II. Inference

How is an inference different than an observation, opinion, or fact?

An inference is what you can determine from the information, facts, and observations. You do this all of the time.

You smell cookies baking. What can you infer?

You hear rain pounding on the roof. What can you infer?

You feel the heat of a bedroom handle. What can you infer?

Difference between observation and inference

A boy comes in wearing a coat. He is holding an umbrella. His shoes are wet.

Observations:

Inferences:

It is raining outside

coat

umbrella

wet

What can we observe?

What can we infer?

So let's make a list.

II. Inference

A. How is an inference different than an observation?

Inference

Inference

INFERENCE

III. What Makes a Good Experiment?

A. You must have a

testable hypothesis

. One that can be answered, and is specific.

Come up with an example:

B. Some experiments benefit from a

control

or

control group.

This is used to see if the test is normal or not.

Controls are used to compare your results to. This is what you keep the same and don’t change.

Underline this in your notes.

What were the controls in our gravity experiment?

If you have a highlighter pull it out now. If not, grab a light colored pencil.

Let's highlight or identify all the controls we used in our experiment.

C. Repeat experiments: The more data we have, the more

reliable

or

accurate

our results will be.

Even measurements can have issues: Each measurement could be slightly off, but if we can average all of our data or measurements, then we can have a better chance of accuracy with our results.

The Behavior of a Cheerleader

If we observe the how a cheerleader acts, just one, can we really get a good idea of how most behave?

What about our sports example? Can one person's opinion of their favorite sport really give us an idea of everyone's favorite?

With more information we can paint a more accurate picture of what is really going on.

Repeat experiments and repeated tests...

With more data you can be more accurate!

D1. We also need a

independent variable

. An

independent variable

is what you

change

. This is what you are testing.

Come up with an example:

Variables

Important Term

Independent variable: the variable that is changed or manipulated by the researcher

Let's highlight the independent variables in our gravity experiment.

Please insert this somewhere near dependent variable.

WARNING!!! THIS IS NOT IN YOUR NOTES

D2. While we are testing we will produce the dependent variable. That is the outcome of our test.

Important Term

Dependent variable: the response that we measure or the effects of our change that we made

Highlight time!

Let's find the dependent variable in our gravity experiment.

E. Then we run some sort of test. This will give us

evidence

to help support or not support our hypothesis. Evidence must be

fact

and not an interpretation or inference.

F. During the entire experiment, the hardest thing is to stay impartial.

To be impartial means to try your best to be fair and not make early conclusions.

Don't let your bias or prior experience blind you to truth.

CONTROL

IV. Graphing (Which type of graph should I use and why?)

A. Line Graph

1. Looks like:

2. Why we use it:

used to track changes over time and/or distance.

3. Example: How fast a runner runs over time.

B. Pie Chart

1. Looks like:

2. Why we use it:

Parts of a whole - when you have 100 percent of something. They do not show change over time or distance.

3. Example: survey of people on their favorite sports team.

C. Bar graph

1. Looks like:

2. Why we use it:

Used to compare between different groups or different things.

Example:

D. X-Y Plot

1. Looks like:

2. Why we use it:

used to track changes over time and/or distance.

3. Example: How fast a runner runs over time.

V. Metric System

Way of measuring stuff where everything can be converted by some factor of 10!

Common Measuring Units

mass (weight): gram (g) & kilogram (kg)

volume (space): milliliter (mL) & liter (L)

distance: millimeter (mm), centimeter (cm), and meter (m).

Facts:

100 centimeters = 1 meter

1000 millimeters = 1 meter

1000 milliliter = 1 liter

Do you see any similarities?

Converting between metric units is easier than English units. Let's try some conversions.

50 meters = ? centimeters

750 centimeters = ? meters

912 meters = ? centimeters

8,125 centimeters = ? meters

5,000 cm

7.50 m

91,200 cm

81.25 cm

VI. Measuring

A. Why we measure more than once?

1. All our measurements will be close, but not

perfect or exactly

the same. With more measurements and data we can make

averages (or means)

. This assures us that our results are more

accurate

.

2. Volume:

a measurement of space.

a) How you can find volume:

1. using math equations or

2. using a

graduated cylinder

(a) Looks like:

(b) measurements are in:

(1) English: cups

(2) Metric: liter

How to Measure Volume

the easy way...

Volume

Practice

5 mL

What is the name of the tube that measures volume?

graduated cylinder

17 mL

19 mL

2 mL

2 mL

What is the name of the tube that measures volume?

graduated cylinder

What is the name of the tube that measures volume?

graduated cylinder

Practice

What did we use to measure mass in our class?

triple beam balance

What did we use to measure mass in our class?

triple beam balance

What did we use to measure mass in our class?

triple beam balance

413.9 grams

80.6 grams

47.1 grams

moon walking bear