1. EXPERIMENTAL PSYCHOLOGY
Alla Chavarga
Tuesdays 9:00-11:20am 2412J
or 6:10-8:30pm 432-IA
LABS:
MW 6:10-9:45pm 3106J Kravitz  MW 6:10-9:45pm 4109J Ergun  TR 11:30-3:05pm 3106J Fein  TR 11:30-3:05pm 4109J Hazan

2. Getting Started & Measurement
CHAPTER 2 & 3
Getting Started & Measurement
Lecture Outline
What are the different types of research?
Basic Concepts (Data, Variables, Relationships)
How do we develop research questions?
Scales of Measurement
Evaluating Measures

3. VARIETIES OF PSYCHOLOGICAL RESEARCH
Basic
Designed to describe and understand fundamental psychological phenomena 01
Applied
Designed to shed light on the solution to real-world problems 02

4. VARIETIES OF PSYCHOLOGICAL RESEARCH
Laboratory
Greater Control
Low mundane realism 01
Field
More realistic
High mundane realism 02
Mundane realism – how closely a study mirrors real-life experiences
Experimental realism – the extent to which a study has an impact on the subjects, forces them to take the matter seriously, and involves them in the procedures

5. VARIETIES OF PSYCHOLOGICAL RESEARCH
Quantitative
Includes quantitative data and statistical analysis 01
Qualitative
Includes narrative descriptions, content analyses, interviews 02
Much research includes elements of both:
Depression and anxiety studies
Case studies of drug/alcohol users

6. BASIC CONCEPTS Variables Sampling and Measurement
Statistical relationships between variables
Differences between groups
Correlations between quantitative variables
CORRELATION IS NOT CAUSATION
How do we establish causation? Can we ever?
Variables
Independent
Dependent
Sampling and Measurement

7. How do we develop research questions?
Our own observations Example: Kitty Genovese
Serendipitous events Discovering something while looking for something else (”edge detectors”)
Hubel and Wiesel (1959, 1962): “edge detectors”

8. How do we develop research questions?
Research teams and the “What’s next?” question
Programs of research Series of interrelated studies
Research teams and the apprentice model
Replication and Extension
Exact replication is rare (however, the norm in Pavlov’s lab; training new workers)
Extension: partial replication with new features added to extend the findings

9. MEASUREMENT What do we measure? How do we measure it? 01
Develop Measures from Constructs
Construct: a hypothetical, explanatory variable that is not directly observable.
Select variables that represent or are involved in constructs 02 03
Operationalize variables
Operational definitions define concepts and labels by the way they are measured.

10. MEASUREMENT How do we measure: Height? Intelligence? Depression?
Attractiveness?
Passive aggression?

11. Understanding of gravity Visuospatial Sketchpad
MEASUREMENT
Understanding of gravity
Visuospatial Sketchpad
Using habituation to define the construct “understanding of gravity” as preferential looking / time spent looking (seconds).
Construct: Understanding gravity
Operational definition: time spent looking at each test event
Construct is defined as response time to a mental rotation task (seconds, milliseconds).
Construct: visuo-spatial sketchpad
Operational definition: time to complete each mental rotation task

12. Measuring: assigning numbers to events, characteristics, or behaviors
SCALES OF MEASUREMENT
Measuring: assigning numbers to events, characteristics, or behaviors
Category labels or names; no numerical order. 01
NOMINAL
Ranks, positions in order; intervals on scale not equal. 02
ORDINAL
Numerical scale, equal intervals, no absolute zero. 03
INTERVAL
Numerical scale, equal intervals, absolute zero. 04
RATIO

13. IDENTIFY THE SCALE School year (freshman, sophomore, etc) Gender
Amount of change in your pockets
Social Security #
Nominal
Ordinal
Interval
Ratio

14. EVALUATING MEASURES Reliability
The extent to which a measure produces the same result when applied to the same person under the same conditions; the consistency of a measure
Over time (test-retest reliability)
Across items (internal consistency)
Across researchers (inter-rater reliabilty)

15. EVALUATING MEASURES Validity
The extent to which the scores from a measure represent the variable they are intended to.
Face validity
Content validity
Criterion validity
Convergent validity
Discriminant validity