Chapter 2

What is

Science

• What is Science?• Science is a way we look at the natural world.• Science is about asking Questions, it’s about the way you think and see the world

• Why? How? What? When?

• How do birds fly? How is gold made? Why is it so hot today?

• All scientists have something in common, they use the scientific method to gather information.

1. Observing and Questioning- Observations are made directly with our senses.

- Quantitative observations – can be expressed with numbers.- Qualitative observations – cannot be expressed with numbers, quality.

- Scientists make observations with the help of tools or instruments.

Qualitative observations Quantitative observations

Deals with descriptions.Data can be observed but not measured.Colors, textures, smells, tastes, appearance, beauty, etc.Qualitative → Quality

Deals with numbers.Data which can be measured.Length, height, area, volume, weight, speed, time, temperature, humidity, sound levels, cost, members, ages, etc.Quantitative → Quantity

Creamy appearanceSmells sweet

WhiteRich taste

3 Gallonsserving temperature 10º F.

Serving size 4 oz.cost per scoop $2.00

Qualitative data:blue/green color, gold framesmells old and mustytexture shows brush strokes of oil paintpeaceful scene of the countrymasterful brush strokes

Quantitative data:picture is 10" by 14"with frame 14" by 18"weighs 8.5 poundssurface area of painting is 140 sq. in.cost $300

Research

2. Researching - Research helps scientists learn what work has been

done on a particular topic already. - Provides additional information.

Hypothesis

. Develop a Hypothesis - Hypothesis – is a possible explanation for a set of

observations.- It is not a wild guess!- It must be based on observations.- Inferring – is explaining or interpreting the things

you observe based on reasoning from what you already know.- It is a prediction – making a forecast of what will happen in the future based on past experience or evidence.- It must be testable!!!!!- “If” “Then” statement

Designing an ExperimentVariable – is any factor that affects the outcome of an experiment.

- An experiment tests 1 and only 1 variable at a time.- 2 kinds of variables exist.

• Independent variable is the variable you change.

- Also known as manipulated variable.• Dependent variable what you are measuring.

- Also known as the responding variable.Operational definition – is a statement that describes how to measure a particular variable or define a particular term.

Experimental and Control Group

• Groups- Control Group: without independent variable.- Experimental Group: gets everything the control group gets but

with independent variable.

5. Collecting, Organizing, and Analyzing Data- Collecting is record keeping.- Organizing – Put information into tables,

charts, graphs, models (representation of a complex process), etc.- Interpret and communicate the work to others

- To check the work of other scientists!

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2.2 Skills and Methods

Graphing• A graph is a useful tool that may help scientist interpret

data by revealing unexpected patterns.• Line graph – shows how the responding or dependent

variable changes in response to the manipulated or independent variable.• The horizontal axis – runs left to right.• The vertical axis – runs up and down.• Includes a line of best fit – this shows the overall trend of data.• If a graph shows no identifiable trend then there is no

relationship between the variables

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Distance vs. Time

0

100

200

300

400

500

600

Time(seconds)

Dis

tan

ce

(m

ete

rs)

Series1

A

B

C

Graphing• Bar graph – is used to compare a set of measurements,

amounts or changes.

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• A circle graph or pie chart is a divided circle that shows how a part or share of something relates to the whole. • Percentage of the whole.

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Graphing

Interpreting and Analyzing numbers

• Estimate – is an approximation of a number, it is not guessing. Based on known information– Scientists must sometimes rely on estimates when they

cannot obtain exact numbers.– How would you estimate the number of students in this

school?

–Why is it not guessing?

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Scientific Theories• A Scientific Theory is a well

tested explanation for a set of observations or experimented results.• Tested many times.• Can predict future events.• Theories are never fully proven.• Scientist might reject a scientific

theory if new evidence contradicts it.

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Scientific Method

• Scientific Method is a step-by-step organized plan for answering questions and solving problems.• Everyone uses the scientific method! Non-science

careers use materials and processes that follow scientific principles.• Most scientific investigations today span the different

fields of science.

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Scientific Method1. Make Observation and Ask Question 2. Conduct Research 3. Develop Hypothesis4. Experiment (include variables)5. Collect and Analyze Data ,Communicate Results

2.3 Environmental Science

• Everything that surrounds us is the environment.• Draws from all types of science

Biotic factors Abiotic factors

All living parts of the environment All non-living parts of the environment

* Must be alive *Non living (even if they were once living)