The Scientific MethodThe Scientific Method

An overviewAn overview

What is Science?

“Science” derived from Latin ‘to know’Way of asking and answering questionsSeeking answers to questions about

natural phenomena Reduces emotional reactions (Bias), when

solving problems.

Forms of Scientific Inquiry

Discovery or Descriptive Science– Observation– Qualitative vs. Quantitative data– Example: There are two red sweaters in my

closet.Qualitative – descriptions - red sweatersQuantative – numbers - two (2)

Types of Logic

Inductive Reasoning– Derive generalizations based on specific

observations

Types of Logic

Inductive Reasoning– Derive generalizations based on specific

observationsDeductive Reasoning

- Specific predictions follow from general premise

Forms of Scientific Inquiry

Discovery or Descriptive Science– Observation– Qualitative vs. Quantitative data

Hypothesis-Based Science

Scientific Design

Scientific knowledge begins with an observation and a proposed explanation.

Explanation called a hypothesisA hypothesis is testable, measurable, and

duplicatable. In science hypotheses are tested by using them to

make predictions about how a particular system will behave

Scientific Method Video

• Video

Theories and Natural Laws

Theory: a description of the world that covers a relatively large number of phenomena and has met many observational and experimental tests

Can Theories Become Laws? Theories DO NOT become laws. Theories attempt to

explain laws and other phenomena.

A Law is a rule or body of rules and principles governing a phenomenon, example: THE LAW OF GRAVITY, in science, laws are absolute or unquestioned.

A Theory is a set of statements or principles devised to explain a group of facts or phenomena. For a given phenomenon, several theories can exist, and the results can be disputed, this is its basic difference with a law.

Scientific Method in Action

We use the scientific method in everyday life

Example: You got in your car to drive up here and turned the key but the car wouldn’t start (observation)

Scientific Method in Action

Example:You got in your car to drive up here and turned the key but the car wouldn’t start (observation)

Hypothesis: There is something wrong with the car

Scientific Method in Action

Example:You got in your car to drive up here and turned the key but the car wouldn’t start (observation)

Hypothesis: There is something wrong with the car

Predictions: battery dead, ignition problem, out of gas

Scientific Method in Action

Test predictions: turn on headlights, check spark plug wires, dip stick in gas tank

Scientific Method in Action

Test predictions: turn on headlights, check spark plug wires, dip stick in gas tank

Analyze results: headlights work, strong ignition spark, no gas on dip stick-gas gauge reads half full

Scientific Method in Action

Test predictions: turn on headlights, check spark plug wires, dip stick in gas tank

Analyze results: headlights work, strong ignition spark, no gas on dip stick-gas gauge reads half full

Draw conclusion: gauge inaccurate, out of gas

Do you know the difference Do you know the difference between the independent between the independent and dependent variables?and dependent variables?

Independent Variable• The independent, or manipulated

variable, is a factor that’s intentionally varied by the experimenter.

• Ones you change – Manipulated Variable

• Graphed on the x-axisJohn is going to use 25g., 50g., 100g., 250g., 500g. of sugar in his experiment.

Dependent Variable• The dependent, or responding

variable, is the factor that may change as a result of changes made in the independent variable.

• Ones you measure – responding variable

• Graphed on the y-axisIn this case, it would be the size of the loaf of

bread.

Control Group• In a scientific experiment, the control is

the group that serves as the standard of comparison.

• The control group is exposed to the same conditions as the experimental group, except for the variable being tested.

• All experiments should have a control group.

experimental group: group(s) subjected to the independent variable. (Manipulated variable)

reproducibility: producing the same result consistently to verify result. It is therefore important to describe your experimental design in enough detail for others to perform the same experiment.