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Scientific Inquiry


Scientific Inquiry What is Scientific Inquiry Scientific inquiry is the system or procedure by which we seek to understand and explain behavior or the world around us ... – PowerPoint PPT presentation

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Title: Scientific Inquiry

Scientific Inquiry
What is Scientific Inquiry
  • Scientific inquiry is the system or procedure by
    which we seek to understand and explain behavior
    or the world around us

  • On a scale of 1 (dont agree at all) to 5
    (completely agree), how much do you agree with
    the following statement
  • People should use this product because it will
    be beneficial to their health

Science vs Pseudoscience
Canons of Science
  • Deterministic
  • events have meaningful causes
  • Empiricism
  • Good and bad ways to determine cause and effect
  • Making observations
  • Law of Parsimony (Occams Razor)
  • If two explanations are equally good, choose the
    simpler one

Canons of Science
  • Scientific theories must be
  • Testable
  • Falsifiable
  • Define the circumstances under which your theory
    is wrong
  • Repeatable
  • Given the same set of circumstances, the same
    outcome should occur across observations

The Scientific Process
  • We make observations about a specific behavior
  • We develop a theory to account for the behavior
  • Theory ? a testable explanation for a set of
    factors or observations

The Scientific Process
  • We come up with a hypothesis based on our theory
  • (a statement that makes predictions about the
    outcome of a scientific study)
  • For Example
  • If my theory is true under this situation, then X
    should happen
  • If, under this situation, X does not happen, then
    my theory is false

The Scientific Process
  • We conduct a controlled test of our hypothesis
  • We gather objective data
  • We define the variables of interest
  • We analyze the results
  • We accept or reject our hypothesis

  • What is it?
  • Presenting something as fact without sufficient
    scientific evidence
  • Not testable
  • How do we recognize it?
  • Use of scientific-sounding terms (e.g., quantum
  • E.G., ESP, Oxygenated Water, Accupuncture,
    Homeopathy, Feng Shui,

The Flying Spaghetti Monster
Taken from
The Scientific Method
  • Good Science

Good Science
  • We make observations
  • We observe and describe behavior or event
  • E.G., A man, who was leaving a bar, crashes into
    a parked car on the way home

Good Science
  • We develop a theory to explain the behavior or
  • What theories can you come up with to account for
    this behavior and/or outcome?
  • He was drunk
  • Drunk driving causes accidents
  • Alcohol causes impairment of driving abilities
  • Talking on cell phones causes accidents (was he
    on a cell phone?)
  • The brakes on the car malfunctioned
  • The Flying Spaghetti Monster hates people who
    drive after leaving bars

Good Science
  • We come up with a hypothesis based on our theory
  • Remember a good theory must generate hypotheses
    that are testable and falsifiable
  • We must be able to operationally define the
    variables of interest

Good Science
  • Operational Definitions
  • Define, concretely, how you will measure the
    variables of interest

Good Science
  • Theory Alcohol impairs driving ability
  • Hypothesis 1 People who drink alcohol are more
    likely to get into car accidents than those who
    do not drink alcohol
  • Hypothesis 2 Alcohol slows down reaction time
    which causes more accidents
  • Hypothesis 3 Alcohol increases risk-taking while
    driving which causes more accidents

Good Science
  • We conduct a controlled test
  • We select a research design
  • We identify the population and select a sample
  • We define the variables of interest

Research Design
  • Non-experimental vs Experimental designs
  • Non-experimental observe a single group of
    subjects at one point in time
  • Observational studies
  • Survey Studies
  • Experimental involves multiple groups or
    multiple observations across time
  • Control standard against which the effects of
    the experimental condition is compared

Research Design
  • External Validity
  • Can we generalize our findings from the
    experimental context to other people, in other
    places, at other times?

External Validity
External Validity
  • Random Sampling
  • Identify Population
  • All people
  • All adults
  • All adults who drink alcohol
  • All adults who drive after drinking alcohol
  • Select Sample
  • Select sample from population of interest
  • Random
  • Stratified representative of the population on
    key characteristics

Research Design
  • Internal Validity
  • Can we be confident that the observed outcomes
    are due to (caused by) our experimental treatment
    and NOT to some other cause?

Internal Validity
  • To help subjects get in the mood, the bartender
    played loud and upbeat music during the drink
    alcohol condition. No music was played during
    the drink water condition.
  • Confound uncontrolled and/or unmeasured
    characteristic(s) that accounts for the observed

Research Design
  • Random Assignment
  • Place subjects at random into different control
    and experimental conditions
  • Goal is to ensure that potential confounds are
    equally represented in both groups
  • Not always possible, so how do we ensure internal

Testing Hypotheses
  • Independent variable
  • Predictor Variable
  • Variable that is manipulated
  • Dependent Variable
  • Predicted variable
  • Variable that depends on or is affected by the
    independent variable
  • Operational definition
  • Concrete description of how your variables will
    be measured

Testing Hypotheses
  • Observation a man leaves a bar and gets into a
    car accident
  • Hypothesis 1 Heavier drinkers take more risks
    while driving than lighter drinkers
  • Hypothesis 2 Individuals who are intoxicated
    take more risks while driving than individuals
    who are sober

Testing Hypotheses
  • Hypothesis 1
  • IV level of drinking is defined using the
    quantity frequency index
  • DV Risk-taking is defined as
  • frequency of speeding (i.e., number of days per
    week that the individual drives 10 miles over
    the speed limit)
  • Frequency of tailgating

We analyze the data and reject or accept our
Statistical Analysis
Statistical Analysis
Statistical Analysis
Statistical Analysis
Statistical Analysis
Variance Explained
Pirates and Global Warming
Testing Hypotheses
  • Hypothesis 2
  • IV Intoxication is defined as a BAC of .08 mg
    or greater
  • DV Risk-taking is defined through use of a
    simulated driving task as
  • amount of time spent speeding and
  • number of times passing cars on a double yellow

Statistical Analysis
Statistical Analysis
Good Science
  • A theory becomes a law when
  • supporting evidence accumulates over multiple
    tests of the associated hypotheses and
  • it has never been proven false
  • E.g., the law of physics
  • Pseudoscientific claims cannot become laws

Ethical Issues
  • Informed Consent
  • Subjects must be fully informed about
  • Potential risks and benefits of participation
  • Exactly what the study involves
  • Deception
  • Deception can be used if necessary to test
  • Participation is voluntary
  • Coercion is not acceptable