1. Understanding Variability Unraveling the Mystery of the Data’s Message Becoming a “Data Whisperer”

2. Overview of Research Issues and Goals I.Idea – hypothesis Conceptualization – Nominal Definitions – Operational Definitions – Measurement Procedures II.Design (framework/procedure) – Strategy -- Implementation – Data Collection -- Measures III.Statistics – Exploratory – Descriptive – Inferential – Decisions IV.Conclusions in context – Interpretation -- Meaning -- Generalization

3. Search for Cause – Effect connections Information needed to establish a cause is a cause (J. S. Mill) Cause and Effect are related – they covary Cause comes before the Effect in time All alternative Causes are eliminated

4. Cause and Effect Connections can be Necessary and Sufficient – single clear cause Necessary, not Sufficient – combinations of or interactions of variables needed to get effect Sufficient, not Necessary – alternative independent causes exist

5. Goal of Research – to understand variability, how do variables vary (descriptive), when do they vary (covariation), and why do variables vary (causes) Assume that variables cannot vary without cause Research Strategies – depend upon research goals/purposes/constraints

6. Descriptive Research what variables exist and how do variables vary structure of a variable – qualitative or quantitative does the variable exist separately from others one-dimensional or multidimensional possible values and range of values variability within a sample/population

7. Covariation Research (when do variables vary - context) when variables vary, with what do they covary “response variable - response variable” covariation assess strength and direction of relationship “predictor variable – response variable” covariation use one variable to ‘explain’ or ‘predict’ variability in the other variable limitations on ‘causal’ interpretations

8. Search for Cause – Effect connections Information needed to establish a cause is a cause Cause and Effect are related – they covary Cause comes before the Effect in time Logic may support direction - All alternative Causes are eliminated

9. Group Difference Research - focus on typical behavior Quasi-experimental research – covariation related to ‘existing’ differences (grouping) “manipulation” by selection Experimental research – creating groups to control variation of some variables manipulation by control

10. Data Collection Issues Measurement scale – what type of information is provided qualitative and/or quantitative operations that can be performed on measures Source of measures direct physiological measures behavioral observations indirect self reports inferred secondary collected by others

11. Research Setting Controlled conditions ------- Uncontrolled conditions reducing the noise to improve ability to hear the signal allowing noise to see if signal still has impact

12. Evaluating Research Strategies Internal Validity – can outcome be interpreted clearly enhanced by control over all variables and precision of activities External Validity – can outcome be generalized enhanced by inclusion of representative variables and activities

13. Research involves solving a mystery (Must decide on Guilt or Innocence – and hope that decision matches the unknown ‘truth’) understanding why things happen – search for TRUTH! How strong a case can you make, but NEVER 100% confident TRUTH DECISION Innocent Guilty Guilt wrong right Innocence right wrong

14. Research involves solving a mystery (Must decide on Guilt or Innocence – and hope that decision matches the unknown ‘truth’) understanding why things happen – search for TRUTH! (You are like CSI and Prosecutor) Research Strategy – collect the evidence… the data upon which your case will be based Statistics – organize, summarize, and evaluate the strength of the evidence Decide on your ‘interpretation’ of the evidence (Decide on your version of the “Truth” – guilt or innocence) Persuade others of the validity of your interpretation (Other Researchers are like Defense attorney – need only raise doubts!) validity of your research appropriateness of evaluation

15. The ‘Case” a body is found in the library – “who” and/or “what” caused the death? Law & Order: Psychological Research Unit Descriptive Research Covariation Research Causal Evidence Meaningful level of Explanation?

16. Main Characters – all the variables that might be involved Dependent Variable(s) – the ‘response’ variable always present, the basis for the data used to answer the question Independent Variable(s) – explanatory/predictor variable the suspected cause or variable related to the cause Extraneous Variables – all variables not cast in either of the roles above nuisance or confound – possible impacts (evil)(Orient Express) best dealt with in the context of the research strategy – design and procedures (Constant, Control, Random) alternatively, can be dealt with indirectly, using statistical adjustments

17. Qualities of the Main Characters – any variables which will be ‘measured’ Actually are Qualities of Operational Definitions Used reliability – precision and consistency validity – appropriateness and accuracy

18. Recap Research involves solving a mystery – understanding why things happen Research Strategy – collect the evidence… the data upon which your case will be based Statistics – organize, summarize, and evaluate the strength of the evidence Decide on your ‘interpretation’ of the evidence the logic of statistical decision-making Persuade others of the validity of your interpretation validity of your research appropriateness of evaluation

19. Research involves solving a mystery – understanding why things happen Research Strategy – collect the evidence… the data upon which your case will be base Issues: correct variables, measured well (operational definitions) design is appropriate for questions descriptive, covariation, causal absence of contamination (internal validity) can generalize beyond specifics (external validity)

20. Research involves solving a mystery – understanding why things happen Research Strategy – collect the evidence… the data upon which your case will be based Statistics – organize, summarize, and evaluate the strength of the evidence Issues: organize/summarize data (correct descriptive statistics) isolate signal from noise (correct inferential statistics) evaluate the signal (understand what the message is)

21. Research involves solving a mystery – understanding why things happen Research Strategy – collect the evidence… the data upon which your case will be based Statistics – organize, summarize, and evaluate the strength of the evidence Decide on your ‘interpretation’ of the evidence Issues: what do the results mean what decision will you make (guilt or innocence) how confident are you (probability you are wrong)

22. Research involves solving a mystery – understanding why things happen Research Strategy – collect the evidence… the data upon which your case will be based Statistics – organize, summarize, and evaluate the strength of the evidence Decide on your ‘interpretation’ of the evidence Persuade others of the validity of your interpretation Issues: validity of your research validity of your analyses of the data validity of your interpretation of the analyses

23. Mystery Solved