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Published byMarjorie Briggs Modified over 9 years ago
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Experiment 0 Black screen slides
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List 1 – No delay Tiger Tiger Apple Apple Television Television Balloon Balloon Night Night Water Water Orange Orange Jacket Jacket Soda Soda Radio Radio Soap Soap Lamp Lamp
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List 2 – 30 sec delay Tiger Tiger Apple Apple Television Television Balloon Balloon Night Night Water Water Orange Orange Jacket Jacket Soda Soda Radio Radio Soap Soap Lamp Lamp
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List 3 – 30 sec delay Soap Soap Opera Opera New New York York Academy Academy Award Award East East West West North North South South Morning Morning Night Night
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List 4 – No delay That That With With Far Far Then Then Through Through About About Which Which Since Since By By Until Until Among Among Upon Upon
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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
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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
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Scientific Method Evaluate ideas objectively, with degree of confidence Rules on how to collect, summarize, and analyze data
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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
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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
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Scientific progress is achieved incrementally. 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. 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 HOW TO FIND JOURNAL PAPERS – PubMed & PsycInfo
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Low to High Constraint Correlational design Correlational design –Observational –Case Study –Survey –Archival research Experimental design Experimental design –Quasi-Experiment –Experiment
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QUANTIFICATION OF BEHAVIOR QUANTIFICATION OF BEHAVIOR Descriptive Statistics: Descriptive Statistics: –Characteristics of your sample Central tendency: Central tendency: –Mean, Median, Mode
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Mean Arithmetic average Arithmetic average 1 1 6 5 2 Mean = 15 / 5 items = 3 Mean = 15 / 5 items = 3
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Mean Mean Kirkwell WA per capita income: $1,200K Kirkwell WA per capita income: $1,200K Mean = sensitive to extremes Mean = sensitive to extremes
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Median Arrange in order, middle value is median Arrange in order, middle value is median 1 1 2 2 5 6 Median = 2 Median = 2
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Median when even # of items Arrange in order, middle value is median Arrange in order, middle value is median (if even number of items, average two middle values) (if even number of items, average two middle values) 1 1 2 2 5 5 6 7 Median = (2+5)/2 = 3.5 Median = (2+5)/2 = 3.5
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Median Not sensitive to extremes Not sensitive to extremes 1 1 2 2 5 6 Median = 2 Median = 2 1 1 2 2 5 6 billion 6 billion Median = 2 Median = 2 -150 -150 1 2 2 5 6 Median = 2 Median = 2
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Median Median Kirkwell WA per capita income: $55K Kirkwell WA per capita income: $55K
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Median is nonlinear, affected by grouping 1 1 4 Median =1 Median =1 4 4 16 16 Median =4 Median =4 Median for all numbers = (1+4)/2 = 2.5 1 1 4 4 4 16 16 Median =4 Median =4
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Mode Most frequent value Most frequent value 1 1 2 5 6 Mode = 1 Mode = 1
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Mode Mode Kirkwell WA per capita income: $13K Kirkwell WA per capita income: $13K
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Mode is also nonlinear, affected by grouping 1 1 4 Mode =1 Mode =1 4 4 16 16 Mode =4 Mode =4 Mode for all numbers = (1+4)/2 = 2.5 1 1 4 4 4 16 16 Mode =4 Mode =4
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How well central tendency describes data? - need index of dispersion 1 2 3 4 5 6 7 8 9 Mean = 5 Mean = 5 4 4 5 5 5 5 5 6 6
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Dispersion: Range, Standard Deviation 1 2 3 4 5 6 7 8 9 Mean = 5, Range = 8 Mean = 5, Range = 8 4 4 5 5 5 5 5 6 6 Mean = 5, Range = 2 Mean = 5, Range = 2
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Dispersion: Range, Standard Deviation 4 4 4 4 5 6 6 6 6 Mean = 5, Range = 2 Mean = 5, Range = 2 St Dev = 0.94 St Dev = 0.94 4 4 5 5 5 5 5 6 6 Mean = 5, Range = 2 Mean = 5, Range = 2 Std Dev = 0.67 Std Dev = 0.67
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Measurement Scales Nominal or categorical OrdinalIntervalRatio People with the same scale value are the same on some attribute. Scale values have no 'numeric' meaning in the way that you usually think about numbers. People with a higher scale value have more of some attribute. Intervals between adjacent scale values are indeterminate. Intervals between adjacent scale values are equal with respect to attribute being measured. E.g., difference between 8 and 9 is the same as the difference between 76 and 77. Meaningful zero point for the scale. Ratios are equivalent, e.g., the ratio of 2 to 1 is the same as the ratio of 8 to 4. NominalOrdinalIntervalRatioGender.Ethnicity. Marital Status. SES USDA beef ratings (good, choice, prime) Hospitalization Top 20 Countdown Degrees F. Letter Grades IQ Degrees K. Annual income TimeDistance
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Role of Figures in Scientific Papers Argument made in pictures, not words! Argument made in pictures, not words!
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Figures used for: DATA DATA METHOD METHOD THEORY THEORY
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Three mountain test for egocentrism
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Hierarchical memory storage
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Lies, damn lies, and statistics
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eyetracking
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Ages, wealth, length of absence
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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
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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
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VHS 1518.02 Final points Correlation is not causation Correlation is not causation –Ice cream and murders in NYC Single-blind and double-blind designs Single-blind and double-blind designs –Knowledge of which level of the IV subject is assigned to Controlled experiment Controlled experiment –Active treatment vs non-active “treatment” such as a placebo
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