NATURE OF SCIENCEMrs. Cassel

Rm 106

SCIENCE

HOW DO WE “DO” SCIENCE?

Scientific Method (Inquiry)

People

In

Hershey

Eat

Dark

Chocolate

What is Problem or Researchable Question

Gather Information

Create a Hypothesis(if. . . Then. . . Because. . . Statement)

Experiment

Collect and Analyze Data

Form Conclusion

QUALITATIVE VS. QUANTITATIVE

Qualitative Observations or Data that are based on your 5

senses and are DESCRIPTIVE. Ex: The mineral is yellow in color and smells like

rotten eggs.

Quantitative Observations or Data that are measureable and

NUMERICAL. Ex: The mineral has a mass of 26g and a volume

of 13 cm3. Its Density is 2g/cm3.

INDEPENDENT VS. DEPENDENT VARIABLE

Manipulated variable Independent variable The thing you choose to change.

Responding variable Dependent variable The factor that may change because of the

Independent variable. What you are observing or measuring

If I increase the temperature of the water, then the amount of sugar dissolved increases.

The IF part of the hypothesis

The THEN part of the hypothesis

THEORY VS. LAW

Theory An attempt to EXPLAIN something observable in

nature. Supported by much repeated testing. Big Bang Theory: attempts to explain how the

Universe was formed and why we see evidence that the Universe is expanding.

Law Attempts to DESCRIBE something observable in

nature. Does not try to explain it, only states that it happens. Law of Gravity: States that all things in the Universe

are attracted to all things in the Universe with the same force and are dependent on their Mass and Distance between objects.

RESEARCHABLE QUESTIONS

Causal: Cause and Effect Questions Designed to determine whether one or more variables causes or affects one or more outcome variables.

Ex: What is affect of Red Bull on heart rate? What is the effect hand fatigue on reaction time? How does exercise affect the

rate of carbon dioxide production? How is the diffusion of air freshener influenced by

temperature?

How does affect of the gum?

HYPOTHESIS

What is affect of Red Bull on heart rate? If we drink 100 ml of Redbull, then our heart

rate will increase. How does exercise affect the

rate of carbon dioxide production? If we increase our exercise by double, then

the rate of carbon dioxide production will increase.

How is the diffusion of air freshener influenced by temperature?

If we increase the temperature of the air freshener by 10 degrees, the air freshener diffusion will increase.

HYPOTHESIS

If we to the gum, then

will increase.

Quantify the Independent variable. Use terms increase/decrease to show direction of

change.

DATA TABLE

Time Gum

Chewed (min)

Length of

Stretch (cm) Trial1

Length of

stretch (cm)

Trial 2

Length of

Stretch (cm)

Trial 3

2

4

6

When creating a data table you must decide the number of columns and row.

1st column on the left is the Independent Variable

Don’t forget to include a UNIT in the Label

GRAPH

The independent variable is plotted on the x-axis The dependent variable is plotted on the y-axis

DATA ANALYSIS

Trend Line: A line on a graph showing the general direction that a group of points seem to be heading.

RELATIONSHIP OF VARIABLES

Direct Relationship (Positive) This means as the Independent variable INCREASES

the Dependent variable INCREASES.

RELATIONSHIP OF VARIABLES

Inverse Relationship (Negative) This means as the Independent variable

INCREASES the Dependent variable DECREASES.

DATA ANALYSIS

Strength of Relationship: How closely the points follow the trend line, shows the strength of the relationship.

DATA ANALYSIS

In a lab report, the data analysis is where you tell us specific things about the data on your graph. 1. What is the relationship between the two

variables you are observing? (Positive, Negative)

2. What is the strength of that relationship? (Strong, Weak)

3. Give data to support those two things.1. Ex: After 1 minute the gum only stretched 20 cm

whereas at 3 minutes the gum stretched 100 cm.

CONCLUSION

State your conclusion whether you accept, reject, or need to modify your hypothesis.

State how you could improve your experiment to make it more valid and reliable.1. Acknowledge hidden variables that you couldn’t

control or chose not to because of situation. (validity)

2. Increase the number of trials, improve equipment, etc. (reliability)

3. Further Study: Now that you’ve completed this lab, what study might you do based on this one?