California science grade 3 (5)

Observe Infer Compare Classify Measure Use Numbers Communicate Predict Record Data Analyze Data Form a Hypothesis Use Variables Experiment Make a Model 5.. Repeat observations to improve

Investigate and Experiment

The name of this fossil,

Archaeopteryx, means

“ancient wing.”

Science is a way of understanding the world

around us Scientists often ask questions about what they observe They call on many skills to help them answer these questions This process of asking and

answering questions in science is called inquiry.

In this section, you will see how scientists use inquiry skills to learn about dinosaurs

What Is

Science?

Inquiry Skills

These are the inquiry skills scientists use You can use these skills, too

Observe Infer Compare Classify Measure Use Numbers Communicate Predict Record Data Analyze Data Form a Hypothesis Use Variables Experiment Make a Model

5 Scientific progress is made by

asking meaningful questions and

conducting careful investigations

As a basis for understanding

this concept and addressing

the content in the other three

strands, students should develop

their own questions and perform

investigations Students will:

a Repeat observations to improve

accuracy and know that the

results of similar scientific

investigations seldom turn out

exactly the same because of

differences in the things being

investigated, methods being used,

or uncertainty in the observation.

b Differentiate evidence from

opinion and know that

scientists do not rely on claims

or conclusions unless they are

backed by observations that can

be confirmed.

c Use numerical data in describing

and comparing objects, events,

and measurements.

d Predict the outcome of a simple

investigation and compare the

outcome with the prediction.

e Collect data in an investigation

and analyze those data to develop

a logical conclusion.

Investigation and

Experimentation

3

Observation >

Are you an observant person? You might look out the window to see if it is raining You might even listen for rain on the windowsill You make

observations throughout your day Observations

of the world around us often raise questions.

The diagram on this page shows processes

that scientists use to answer questions Many call this the “scientific method.” Scientists don’t

always use all of the steps They may not use them

in the same order.

Inquiry Skills

When you make

observations, you use these skills

Observe Use your senses to learn about an object or event

Classify Place things that share properties together in groups

Measure Find the size, distance, time, volume, area, mass, weight, or temperature of an

object or an event

5

Do you ask “why”

questions when you are

curious about things? The

work of scientists often starts with

an unanswered question Scientists then

suggest a possible answer that can be tested

with an experiment This is known as forming a

hypothesis A good hypothesis must

▸ be based on what you observe.

▸be testable by doing an experiment.

▸ be useful in predicting new findings.

Which of these dinosaurs was a meat eater and

which was a plant eater? Form a hypothesis to

answer this question.

Question and Hypothesis >

3.IE.5.b Differentiate evidence from opinion and know that scientists do not rely on claims or conclusions unless they are backed by observations that can be confi rmed.

Inquiry Skills

When you ask questions and form hypotheses, you use these skills

Infer Form an idea from facts or observations

Form a hypothesis

Make a statement that can be tested to answer

a question

A scientific hypothesis must be testable That

means you must be able to support or disprove your

hypothesis by experimenting When you experiment

you do a hands-on activity to test an idea

Scientists often do research before they experiment

They look in books, scientific journals, or Internet

resources for information that other scientists have

found Scientists also know that they cannot rely on

someone’s opinion or claim unless it has been backed

up by observations

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Now it’s time to test your hypothesis with an

experiment In experiments you change one vari-able to see what happens with another varivari-able For example, you might make a model to find out how the type of soil affects the shape of a dinosaur’s footprint What would happen if you changed both the type of soil and the size of the dinosaur?

Experiments must be able to be repeated, too This allows scientists to evaluate and compare each other’s work They can check their own work too! So

a good experiment must:

▸ change only one variable at a time

▸ be able to be repeated.

Experiment >

Inquiry Skills

When you experiment, you use these skills

Experiment Perform

a test to support or disprove a hypothesis

Use variables Identify things in an experiment that can be changed or controlled

Predict State possible results of an event or experiment

Make a model Make something to represent

an object or event

Before you test a hypothesis, you must have a plan

When scientists make a plan, they think about the

variables they want to test A variable is something that

can be changed or controlled It is important to change

or control only one variable at a time Keep all other

parts of the experiment the same That way you will

know what caused your results

After they determine their variables, scientists

decide what materials they will need Then they write

a procedure A procedure is a series of numbered steps

that tell what to do first, next, and last

After scientists have developed their procedure, they

predict what will happen when they follow it To predict

means to tell what you think will happen

9

W hat’s one important part of a science experiment? Collecting and recording good data! When data are collected they may then

be explained, or interpreted Collecting and interpreting data often requires working with numbers.

This scientist will measure and record the length and

weight of the dinosaur

fossil she is studying.

When scientists follow their procedure, they make

observations and record data Data is information

Measurements are a type of data Scientists use

measurements whenever they can to describe objects

and events Scientists measure such things as length,

volume, mass, temperature, and time

Scientists repeat their procedure several times

This helps them know if their results are correct They

often compare their results with other scientists Other

scientists will repeat the procedure to see if they get

the same results

Inquiry Skills

When you collect and interpret data, you use these skills

Use Numbers Order, count, add, subtract, multiply, and divide to explain data

Measure Find the size, distance, time, volume, area, mass, weight, or temperature of an object

or an event

Record Data

Accurately arrange and store information collected in science investigations

Analyze Data Use the information that has been gathered to answer questions or solve a problem

Collecting Data >

11

You’ve collected and interpreted data Now what? It is time to draw a conclusion A conclusion

states whether your data

support your hypothesis

But what if your data do not

support your hypothesis?

Perhaps different

experiments are needed

Perhaps a new question

will result

Scientists also share

with others what they have found This allows scientists around the

world to stay informed And it allows scientists to check each other’s work Scientists also share what they have learned with the public Have you ever been to a museum with displays of dinosaur fossils like this?

Scientists organize and analyze their data to see if

the results support or disprove their hypothesis They

determine if their prediction matched their results

They draw conclusions and try to explain their results

When you draw conclusions you interpret observations

to answer questions

Sometimes the results of an experiment lead to new

questions These questions can be used to form a new

hypothesis and perform new tests The process starts

all over again This process of asking and answering

questions is called the scientific method

Inquiry Skills

When you draw conclusions and communicate results, you use this skill

Communicate Share information

Conclusion

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Now it’s your turn to be a scientist and design a

good experiment

Most science experiments start with an unanswered question Students wondered how dinosaur footsteps could show how large the animal was This was their question:

Question

• Does the length of your leg affect the distance

between your footsteps?

The students turned the question into a statement that

can be tested This is called a hypothesis A hypothesis is

an “if… then…” statement

Hypothesis

If the leg is longer, then the distance between the footsteps will be greater

Forming a Hypothesis

Make a plan to test the hypothesis

The first step is to identify what is being tested

and what is not being tested These are called

your variables.

Controlled variables are not being tested These

variables remain constant during an experiment

In this experiment the controlled variables will be:

• The location of the test

• The starting point for the test

The only thing that will change is the factor you are

testing This is the independent variable Your

independent variables will be the length of the

leg of each student tested The dependent variable

is what you are measuring In this experiment

the dependent variable is the distance between

the footsteps

Defining Variables

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Design an experiment to test the hypothesis Here is an experiment a group of students

designed to test this hypothesis

Procedure

1 Choose three classmates with different lengths

of leg Measure the length from the waist to the ground Record each length

2 Predict Which student will have the longest

footstep?

3 Measure a 3 meter piece of butcher paper Mark

a START line at one end of the paper

4 Have students take 3 normal steps from the

START line Measure each footstep from heel to heel Record your measurements in a data chart

5 Repeat the experiment to verify your results.

6 Was your prediction correct?

Designing an Experiment

Analyzing Data

In order to communicate the results of an experiment the data need to be presented in a clear way These students used the data chart to make a bar graph that shows how the length of the leg relates to the length of the footstep

Does this graph help others understand the results of the experiment? Why is it important to repeat experiments?

3 IE 5.a Repeat observations to improve accuracy and know that the results of similar scientific investigations seldom turn out exactly the same because of differences

in the things being investigated, methods being used, or uncertainty in the observation • 3 IE 5.c Use numerical data in describing and comparing objects, events, and measurements • 3 IE 5.d Predict the outcome of a simple investigation and compare the outcome with the prediction • 3 IE 5.e Collect data in an investigation and analyze those data to develop a logical conclusion.

17

It is important to repeat experiments Why is this so? Science experiments produce new ideas New

questions may arise After reading the results of this experiment, other students wrote down the following questions they were interested in studying The exciting thing about science experiments is that they can cause new questions to arise For example:

• What if you used an inclined plane instead of a flat surface?

Write a hypothesis for one of these questions or one of your own Talk about it with your class Work together to write a plan to test this new hypothesis

Forming New Questions