VARIABLES & SCIENTIFIC METHOD

Unit 1 – Intro to Science

Unit 1 – Intro to Science

Variables

Variables

There are 3 types of variables Independent Variable

The thing that you change Dependent Variable

The outcome, depend on the independent variable

ControlsThings you leave the same, a standard of comparison, not all experiments have controls.

Constants

Sometimes these are confused with CONTROLS.

Constants are things that remain consistent throughout the entire experiment.

Temperature, materials, location, etc…

Example 1- Independent Variable Investigating how a

weight affects the length of an elastic band.

Independent Variable

The weight applied

You decided which weights to use

Example 1- Dependent Variable Investigating how a

weight affects the length of an elastic band.

Dependent Variable Length is the

dependent variable.You measure the resulting length of the elastic band

Example 2 – Independent Variable The longer the

amount of time spent studying causes an increase in test scores

Independent Variable Time spent

studyingYou decide how long/much to study for a test.

Example 2 – Dependent Variable The longer the

amount of time spent studying causes an increase in test scores

Dependent Variable Test scores

This should change based on how long you study

Additional Examples

Question Independent Variable(What is changed -

Input)

Dependent Variable(What is observed -

Output)

How much water flows through a faucet at different openings?

Water faucet opening•closed•half open•fully open

Amount of water flowing per minute measured in mL per

minute

Does heating a cup of water allow it to absorb

more sugar?

Temperature of water measured in degrees

Celcius

Amount of sugar that dissolves completely measured in grams

Independent Variable

The independent variable is always located on the X axis of a graph.

It is usually the “X” in a table or equation.

The independent variable stands alone (not dependent on anything)

The independent variable is what happens first.

Dependent Variable

The dependent variable is always located on the Y axis of a graph.

It is usually the “Y” in a table or equation.

The dependent variable DEPENDS on theindependent variable.

The dependent variable is what happens second.

Unit 1 – Intro to Science

Scientific Method

Science

“Sci” means “to know”

We know things from facts that can be proven through data and evidence

We gather facts through the scientific method.

The Scientific Method A pattern that

scientist use to investigate or solve a specific problem.

Steps in the Scientific Method1. Identify a problem2. Research the problem3. Develop a hypothesis4. Design experiment (Independent and

Dependent)5. Test/Conduct the Experiment6. Analyze the Results7. Form Conclusions8. Repeat / Publish

Example 1

Identify a problem Noticing that

many salamanders near a pond have curved, not straight tails.

Example 1

Research the Problem Go to library

and research reputable journals.

Research using internet but only trustworthy sources.

Prior knowledge or experience

Example 1

Develop a Hypothesis A hypothesis is a

possible explanation for a set of observations or answer to scientific question, predicts an outcome

Should be written as “I think _______

because______.”

Example 1

Design an Experiment Is a test made

up of variables that can be tested or compared. There are 3 types of variables in an experiment.

Example 1

Carry out experiment

Make observations during the experiment Types of

observations Quantitative

(Quantity) Using

numbers Qualitative

(Quality) Descriptive Using your 5

senses (touch, smell, etc.

Example 1

Analyze Data Charts Graphs Tables Averages Visual Ratings

Bar Graphs, Line Graphs normally used.

Example 1

Form a conclusion We summarize

what the data (tables, charts and graphs) reveals.

Discuss any changes you may want to make in your experiment and why.