The Scientific Method The Scientific Method An overview An overview
Jan 17, 2018
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.