480 likes | 558 Views
Experiment 0 Black screen slides. Tiger Apple Television Balloon Night Water Orange Jacket Soda Radio Soap Lamp. List 1 – No delay. Tiger Apple Television Balloon Night Water Orange Jacket Soda Radio Soap Lamp. List 2 – 30 sec delay. Soap Opera New York Academy
E N D
Tiger Apple Television Balloon Night Water Orange Jacket Soda Radio Soap Lamp List 1 – No delay
Tiger Apple Television Balloon Night Water Orange Jacket Soda Radio Soap Lamp List 2 – 30 sec delay
Soap Opera New York Academy Award East West North South Morning Night List 3 – 30 sec delay
That With Far Then Through About Which Since By Until Among Upon List 4 – No delay
RESEARCH VARIABLES Independent variable (IV): Variable manipulated by researcher Dependent variable (DV): Variable measured by researcher, expected to change as a result of researcher’s manipulation (“depends on IV”) Control variables (CV): Factors kept constant (e.g., confederate, room). Random variables (RV): Factors allowed to vary randomly. (e.g. time of day effects, fatigue, motivation) Confounding variable: Variable’s levels covary with IV’s and may be responsible for changes
Research in Psychology • WHAT DRIVES PSYCHOLOGICAL RESEARCH? • Existing Theories: Evaluate, extend, or discredit • Other Research: Replicate, extend, or discredit - Personal Observation Casual curiosity or new interest
Scientific Method • Evaluate ideas objectively, with degree of confidence • Rules on how to collect, summarize, and analyze data
Evaluating Without Scientific Method • “Clever Hans” phenomenon, facilitated autistic communication • Neither knew answer if questioner failed to know it • Hans was sensitive to primate nonverbal cues
Science is a set of rules to keep us from lying to each other • Experiments allow conclusion about causality: • Control: Keep variables & groups constant or equivalent • Manipulation: Change only one thing at a time
Scientific progress is achieved incrementally. Share findings with scientists and public via peer-reviewed journals, or conferences, or books. Peer review takes time (up to 1 year after submission), but allows other experts to evaluate and critique your work, occasionally revealing flaws or limitations of the study. HOW TO FIND JOURNAL PAPERS – PubMed & PsycInfo
Low to High Constraint • Correlational design • Observational • Case Study • Survey • Archival research • Experimental design • Quasi-Experiment • Experiment
QUANTIFICATION OF BEHAVIOR Descriptive Statistics: Characteristics of your sample Central tendency: Mean, Median, Mode
Mean • Arithmetic average • 1 • 1 • 6 • 5 • 2 • Mean = 15 / 5 items = 3
Mean Kirkwell WA per capita income: $1,200K Mean = sensitive to extremes
Median • Arrange in order, middle value is median • 1 • 1 • 2 • 5 • 6 • Median = 2
Median when even # of items • Arrange in order, middle value is median • (if even number of items, average two middle values) • 1 • 1 • 2 • 5 • 6 • 7 • Median = (2+5)/2 = 3.5
Not sensitive to extremes 1 1 2 5 6 Median = 2 1 1 2 5 6 billion Median = 2 Median • -150 • 1 • 2 • 5 • 6 • Median = 2
Median Kirkwell WA per capita income: $55K
1 1 4 Median =1 4 4 16 Median =4 Median is nonlinear, affected by grouping • 1 • 1 • 4 • 4 • 4 • 16 • Median =4 Median for all numbers = (1+4)/2 = 2.5
Mode • Most frequent value • 1 • 1 • 2 • 5 • 6 • Mode = 1
Mode Kirkwell WA per capita income: $13K
1 1 4 Mode =1 4 4 16 Mode =4 Mode is also nonlinear, affected by grouping • 1 • 1 • 4 • 4 • 4 • 16 • Mode =4 Mode for all numbers = (1+4)/2 = 2.5
1 2 3 4 5 6 7 8 9 Mean = 5 4 4 5 5 5 5 5 6 6 Mean = 5 How well central tendency describes data? - need index of dispersion
1 2 3 4 5 6 7 8 9 Mean = 5, Range = 8 4 4 5 5 5 5 5 6 6 Mean = 5, Range = 2 Dispersion:Range, Standard Deviation
4 4 4 4 5 6 6 6 6 Mean = 5, Range = 2 St Dev = 0.94 4 4 5 5 5 5 5 6 6 Mean = 5, Range = 2 Std Dev = 0.67 Dispersion:Range, Standard Deviation
Role of Figuresin Scientific Papers • Argument made in pictures, not words!
Figures used for: • DATA • METHOD • THEORY
RESEARCH VARIABLES Independent variable (IV): Variable manipulated by researcher Dependent variable (DV): Variable measured by researcher, expected to change as a result of researcher’s manipulation (“depends on IV”) Control variables (CV): Factors kept constant (e.g., confederate, room). Random variables (RV): Factors allowed to vary randomly. (e.g. time of day effects, fatigue, motivation) Confounding variable: Variable’s levels covary with IV’s and may be responsible for changes
DESIGN Within-subject design - each participant exposed to every level of IV (person acts as own control) Between-subject design - each participants exposed to one level of IV (and unaware of what other participants are exposed to) Counterbalancing - ordering presentation levels of IV to eliminate confounding OPERATIONAL DEFINITION Specify operations required to manipulate or measure concept. e.g. Anxiety is not vaguely measured by objectively through scales, checkboxes, etc
VHS 1518.02 Final points • Correlation is not causation • Ice cream and murders in NYC • Single-blind and double-blind designs • Knowledge of which level of the IV subject is assigned to • Controlled experiment • Active treatment vs non-active “treatment” such as a placebo