PSYCH STATS

• Why take a research methods course

  • To learn how to apply science to the study of human behavior
  • To understand and interpret others' research
  • To evaluate claims in everyday media
  • To discover how to acquire knowledge and make decisions by applying the scientific method
• Non-scientific approaches


  • Method of tenacity
  • Method of intuition
  • Method of authority
  • Rational method
  • Method of empiricism
• What is the goal of scientific method?

  
  

  To obtain better-quality answers
• Tenacity


  • Information accepted as true because it has always been believed or because superstition supports it
  • Limitations: potential inaccuracies; no method for correcting erroneous ideas
• Intuition


  • Information accepted on the basis of a hunch
  • Limitation: no method for separating accurate from inaccurate knowledge
• Method of authority


  • Relies on information or answers from an expert in the field
  • Good starting point—often quickest and easiest way to obtain answers
  • Limitations: does not always provide accurate information, often accepts expert's statements as fact (method of faith), not all "experts" are experts
• Rational method


  • Seeking answers by logical reasoning
  • Premise statements are assumed to be true
  • People are not very good at logical reasoning, sometimes the argument does not logically support the conclusion
• Empirical method


  • Answering questions by direct observation or personal experience
  • Limitations: observations can be misinterpreted, sensory experience can be swayed by beliefs, time-consuming and sometimes dangerous
• Scientific method


  • Involves formulating specific questions and then systematically finding answers
  • Combines several different methods of acquiring knowledge
• Induction


  A small set of specific observations is the basis for forming a general statement about a larger set of possible observations
• Deduction


  A general statement is the basis for reaching a conclusion about specific examples
• Variables


  Characteristics or conditions that change or have different values for different individuals
• Hypothesis


  • A statement that describes or explains a relationship between variables; "best guess"
  • A hypothesis can lead to several different observable and measurable predictions
• Three important principles of the scientific method:
• Empirical


  • Answers are obtained by making structured or systematic observations
  • Results will provide clear support for the hypothesis or will clearly refute the hypothesis
• Public


  • Observations are available for evaluation by others
  • Replication is key to the scientific method
• Objective


  Outcome is not skewed by bias
• Quantitative research


  • Produces numerical scores
  • Submitted to statistical analysis for summary and interpretation
• Qualitative research


  • Based on making observations
  • Summarized and interpreted in a narrative report
• Primary sources


  Firsthand reports in which the authors describe their own observations
• Secondary sources


  Secondhand reports in which the authors discuss someone else's observations
• PsycARTICLES


  • The American Psychological Association's (APA) definitive source of full-text, peer-reviewed scholarly and scientific articles in psychology
  • Contains more than 163,000 articles from more than 80 journals published by the APA, the Educational Publishing Foundation (EPF), and from allied organizations
• ERIC


  • Provides access to education literature and resources
  • Information from journals included in the Current Index of Journals in Education and Resources in Education Index
• MEDLINE


  Provides the authoritative medical information on medicine, nursing, dentistry, veterinary medicine, the health care system, and pre-clinical sciences
• Well-defined, easily observed, and easily measured variables

  Examples: height and weight
• Intangible, abstract attributes


  • Examples: motivation or self-esteem
  • Measurement is more complicated
• Theory


  A set of statements about mechanisms underlying a particular behavior
• Constructs (hypothetical constructs)


  • Hypothetical entities created from theory and speculation
  • Cannot be seen, but are assumed to exist
  • Help explain and predict behavior in a theory
• Validity and reliability


  Two general criteria for evaluating the quality of any measurement procedure
• Consistency


  Demonstrated by a positive relationship where two scores change together in the same direction, or a negative relationship where the two measures change in opposite directions
• Correlation


  • Used to determine the consistency of a relationship
  • Consistent positive relationship: a correlation near +1.00
  • Consistent negative relationship: a correlation near -1.00
  • Inconsistent relationship: a correlation near zero
• Six common definitions of validity

  • Face validity
  • Concurrent validity
  • Predictive validity
  • Construct validity
  • Convergent validity
  • Divergent validity
• Reliability of measurement


  • Stability or the consistency of the measurements produced by a specific measurement procedure
  • Measured Score = True Score + Error
• Sources of error


  • Observer error
  • Environmental changes
  • Participant changes
• Types and measures of reliability

  • Successive measurements (test-retest reliability)
  • Simultaneous measurements (inter-rater reliability)
  • Internal consistency (split-half reliability)
• Scales of measurement


  • The set of categories used for classification
  • Involves two components: set of categories and procedure for assigning individuals to categories
• Four types of measurement scales

  • Nominal scale
  • Ordinal scale
  • Interval scale
  • Ratio scale
• Research ethics


  • Responsibility of researchers to be honest and respectful to all individuals who are affected by their research studies or their reports of the studies' results
  • Guided by the American Psychological Association's ethical principles for research
• Basic categories of research design

  • Ensuring welfare and dignity of participants/subjects
  • Accuracy in reporting research results
• Institutional Review Boards (IRBs)


  Reviews human experimental research