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Placebo Effect
The placebo effect is any reaction to the administration of a placebo that is both clinically significant and salutary. A placebo is any treatment prescribed for a condition for which it is physically ineffective. The placebo effect has been successfully and repeatedly demonstrated on variables that are subjectively experienced, such as pain reduction, coping mechanisms, emotional well-being, and cognitions. The majority of research has centered on pain relief, also known as placebo analgesia. The magnitude of the effect and the percentage of those affected depend on a number of factors, but research indicates that approximately one third of individuals who receive a placebo believing it to be a potent treatment report a significant analgesic effect.
The research involving objective measures of beneficence has been more controversial. ...
- Bayesian Statistics
- Descriptive Statistics
- Central Tendency, Measures of
- Cohen’s d Statistic
- Cohen’s f Statistic
- Correspondence Analysis
- Descriptive Statistics
- Effect Size, Measures of
- Eta-Squared
- Factor Loadings
- Mean
- Median
- Mode
- Partial Eta-Squared
- Range
- Relative Measures of Dispersion
- Standard Deviation
- Statistic
- Trimmed Mean
- Variability, Measure of
- Variance
- Distributions
- z Distribution
- Bernoulli Distribution
- Beta Distribution
- Binomial Distribution
- Copula Functions
- Cumulative Frequency Distribution
- Distribution
- Frequency Distribution
- Kurtosis
- Law of Large Numbers
- Negative Hypergeometric Distribution
- Normal Distribution
- Normalizing Data
- Poisson Distribution
- Quetelet’s Index
- Sampling Distributions
- Weibull Distribution
- Winsorize
- Graphical Displays of Data
- Bar Chart
- Box-and-Whisker Plot
- Column Graph
- Data Visualization
- Exponential Random Graph Models
- Forest Plot
- Frequency Table
- Funnel Plot
- Graph Theory
- Graphical Display of Data
- Growth Curve
- Histogram
- L’Abbé Plot
- Line Graph
- Nomograms
- Ogive
- Pie Chart
- Radial Plot
- Residual Plot
- Scatterplot
- Spaghetti Plot
- U-Shaped Curve
- Visual Analysis
- Visual Display of Quantitative Information
- Hypothesis Testing
- p Value
- Alternative Hypotheses
- Beta
- Critical Value
- Decision Rule
- Equivalence Hypothesis Testing
- Hypothesis
- Nondirectional Hypotheses
- Nonsignificance
- Null Hypothesis
- One-Tailed Test
- Power
- Power Analysis
- Significance Level, Concept of
- Significance Level, Interpretation and Construction
- Significance, Statistical
- Two-Tailed Test
- Type I Error
- Type II Error
- Type III Error
- Important Publications
- “Coefficient Alpha and the Internal Structure of Tests”
- “Convergent and Discriminant Validation by the Multitrait–Multimethod Matrix”
- “Meta-Analysis of Psychotherapy Outcome Studies”
- “On the Theory of Scales of Measurement”
- “Probable Error of a Mean, The”
- “Psychometric Experiments”
- “Sequential Tests of Statistical Hypotheses”
- “Structural Holes: The Social Structure of Competition”
- “Technique for the Measurement of Attitudes, A”
- “Validity”
- Aptitudes and Instructional Methods
- Doctrine of Chances, The
- Logic of Scientific Discovery, The
- Nonparametric Statistics for the Behavioral Sciences
- Probabilistic Models for Some Intelligence and Attainment Tests
- Social Network Analysis Methodsand Applications
- Statistical Power Analysis for the Behavioral Sciences
- Strength of Weak Ties
- Structural Equivalence of Individuals in Social Networks
- Teoria Statistica Delle Classi e Calcolo Delle Probabilità
- Inferential Statistics
- Association, Measures of
- Coefficient of Concordance
- Coefficient of Variation
- Coefficients of Alienation and Determination
- Confidence Intervals
- Correlation Coefficient
- Margin of Error
- Nonparametric Statistics
- Odds Ratio
- Parameters
- Parametric Statistics
- Partial Correlation
- Pearson Product-Moment Correlation Coefficient
- Polychoric Correlation Coefficient
- Q-Statistic
- R2
- Randomization Tests
- Regression Coefficient
- Semipartial Correlation Coefficient
- Spearman Rank Order Correlation
- Standard Error of Estimate
- Standard Error of the Mean
- Student’s t Test
- Unbiased Estimator
- Weights
- Item Response Theory
- Mathematical Concepts
- Measurement Concepts
- z Score
- Categorizing Continuous Data
- Ceiling Effect
- Cut Scores
- False Positive
- Gain Scores, Analysis of
- Instrumentation
- Interval Recording
- Ipsative Data
- Item Analysis
- Item–Test Correlation
- Measurement Invariance
- Observations
- Partial Measurement Invariance
- Percentile Rank
- Psychometrics
- Random Error
- Raw Scores
- Response Bias
- Rubrics
- Sensitivity
- Social Desirability
- Sociograms
- Sociometric Tests
- Specificity
- Standardized Score
- Survey
- Tau Equivalence
- Test
- Then-Test
- True Positive
- Organizations
- Publishing
- Qualitative Research
- Case Study
- Content Analysis
- Conversation Analysis
- Critical Case
- Discourse Analysis
- Ethnography
- Field Notes
- Focus Group
- Instrumental Case Study
- Interval Recording
- Interviewing
- Member Checks
- Memos
- Multiple Case Study
- Narrative Research
- Naturalistic Inquiry
- Naturalistic Observation
- Qualitative Research
- Saturation
- Semi-Structured Interview
- Think-Aloud Methods
- Reliability of Scores
- Correction for Attenuation
- Cronbach’s Alpha
- Internal Consistency Reliability
- Interrater Reliability
- KR-20
- Krippendorff’s Alpha
- McDonald’s Omega Hierarchical
- Parallel Forms Reliability
- Reliability
- Spearman–Brown Prophecy Formula
- Split-Half Reliability
- Standard Error of Measurement
- Test–Retest Reliability
- True Score
- Research Design Concepts
- Aptitude–Treatment Interaction
- Cause and Effect
- Concomitant Variable
- Confounding
- Control Group
- Good Clinical Research Practice
- Interaction
- Internet-Based Research Methods
- Intervention
- Matching
- Mortality
- Multiple Case Study
- Natural Experiments
- Network Analysis
- Peer Effects
- Placebo
- Reciprocity
- Replication
- Research
- Research Design Principles
- Treatment(s)
- Triangulation
- Unit of Analysis
- Yoked Control Procedure
- Research Designs
- A Priori Monte Carlo Simulation
- Action Research
- Adaptive Designs in Clinical Trials
- Alternating Treatments Design
- Applied Research
- Balanced Incomplete Block Design
- Basket Trials Design
- Behavior Analysis Design
- Block Design
- Blockmodeling
- Case-Only Design
- Causal-Comparative Design
- Changing Criterion Design
- Cohort Design
- Completely Randomized Design
- Confirmatory Research
- Crossover Design
- Cross-Sectional Design
- Double-Blind Procedure
- Evaluation Research Design
- Ex Post Facto Study
- Experimental Design
- Exploratory Research
- Factorial Design
- Field Study
- Group-Sequential Designs in Clinical Trials
- Laboratory Experiments
- Latin Square Design
- Longitudinal Design
- Meta-Analysis
- Mixed Methods Design
- Mixed Model Design
- Mixture Models
- Monte Carlo Simulation
- Multiple Baseline Single Case Experimental Design
- Nested Factor Design
- Nonexperimental Designs
- Observational Research
- Panel Design
- Partially Randomized Preference Trial Design
- Pilot Study
- Pragmatic Study
- Pre-Experimental Designs
- Pretest–Posttest Design
- Propensity Score Matching
- Prospective Study
- Quadratic Assignment Procedure
- Quantitative Research
- Quasi-Experimental Design
- Randomized Block Design
- Repeated Measures Design
- Response Surface Design
- Retrospective Study
- Sequential Design
- Single-Blind Study
- Single-Case Research Design
- Split-Plot Factorial Design
- Stepped-Wedge Design
- Stepwise Model Selection
- Thought Experiments
- Time-Lag Study
- Time-Series Study
- Triple-Blind Study
- True Experimental Design
- Umbrella Trials Design
- Wennberg Design
- Within-Subjects Design
- Zelen’s Randomized Consent Design
- Research Ethics
- Adverse Event Reporting
- Animal Research
- Anonymity
- Assent
- Belmont Report
- Beneficence
- Confidentiality
- Cultural Competence
- Data and Safety Monitoring
- Debriefing
- Deception
- Declaration of Helsinki
- Ethics in the Research Process
- Informed Consent
- Justice and Social Science Research
- Multisite Research Studies
- Nuremberg Code
- Participants
- Recruitment
- Respect for Persons
- Risk in Human Subjects Research
- Transparency
- Research Process
- Biological and Technical Replicates
- Clinical Significance
- Clinical Trial
- Cognitive Laboratory
- Cross-Validation
- Data Cleaning
- Data Mining
- Data Snooping
- Delphi Technique
- Evidence-Based Decision Making
- Exploratory Data Analysis
- Follow-Up
- Inference: Deductive and Inductive
- Last Observation Carried Forward
- Masking
- Multisite Research Studies
- Operationalizing
- Primary Data Source
- Protocol
- Q Methodology
- Research Hypothesis
- Research Question
- Scientific Method
- Secondary Data Source
- SPIRIT 2013 Statement
- Standardization
- Statistical Control
- Type III Error
- Wave
- Research Validity Issues
- Bias
- Critical Thinking
- Ecological Validity
- Experimenter Expectancy Effect
- External Validity
- File Drawer Problem
- Hawthorne Effect
- Heisenberg Effect
- Instrumentation as a Threat to Internal Validity
- Internal Validity
- John Henry Effect
- Multiple Treatment Interference
- Multivalued Treatment Effects
- Nonclassical Experimenter Effects
- Order Effects
- Placebo Effect
- Pretest Sensitization
- Random Assignment
- Reactive Arrangements
- Regression to the Mean
- Selection Bias
- Sequence Effects
- Threats to Validity
- Validity of Research Conclusions
- Volunteer Bias
- White Noise
- Sampling
- Cluster Sampling
- Comparison-Focused Sampling
- Convenience Sampling
- Demographics
- Error
- Exclusion Criteria
- Experience Sampling Method
- Gibbs Sampler
- Nested Sampling
- Network Sampling
- Nonprobability Sampling
- Population
- Probability Sampling
- Proportional Sampling
- Quota Sampling
- Random Sampling
- Random Selection
- Sample
- Sample Size
- Sample Size Planning
- Sampling
- Sampling Error
- Sequential Sampling
- Stratified Sampling
- Survey Sampling
- Systematic Sampling
- Theoretical Sampling
- Underrepresented Groups
- Scaling
- Social Network Analysis
- Alters
- Connectivity
- Core-Periphery Structure
- Ego-Centric Networks
- International Network for Social Network Analysis
- Name Generator
- Network Boundaries
- Network Composition
- Network Density
- Network Distance
- Network Matrices
- Network Meta-Analysis
- Network Sampling
- Network Size
- Network Structure
- Network Visualization
- Node, Relationship, and Network Attributes
- Nodes and Relationships
- One-Mode Data
- Social Network Analysis
- Sociograms
- Structural Holes
- Two-Mode Data
- Whole Networks
- Software Applications
- Statistical Assumptions
- Statistical Concepts
- Akaike Information Criterion
- Autocorrelation
- Biased Estimator
- Centrality
- Cohen’s Kappa
- Collinearity
- Correlation
- Criterion Problem
- Critical Difference
- Data Mining
- Data Snooping
- Degrees of Freedom
- Directional Hypothesis
- Disturbance Terms
- Error Rates
- Expected Value
- Factorial Invariance
- Fixed-Effects Model
- Hedges’ g
- Heterogeneity
- Inclusion Criteria
- Influence Statistics
- Influential Data Points
- Intraclass Correlation
- Latent Change Score
- Latent Variable
- Likelihood Principle
- Likelihood Ratio Statistic
- Loglinear Models
- Machine Learning
- Main Effects
- Markov Chains
- McDonald’s Omega Hierarchical
- Method Variance
- Mixed- and Random-Effects Models
- Multilevel Modeling
- Multiplicity Problem
- Neural Networks
- Nuisance Parameters
- Odds
- Omega Squared
- Orthogonal Comparisons
- Outlier
- Overfitting
- Partial Factorial Invariance
- Pooled Variance
- Precision
- Quality Effects Model
- Random-Effects Models
- Regression Artifacts
- Regression Discontinuity
- Residuals
- Restriction of Range
- Robust
- Robust Maximum Likelihood
- Root Mean Square Error
- Rosenthal Effect
- Semi-Interquartile Range
- Serial Correlation
- Shrinkage
- Simple Main Effects
- Simpson’s Paradox
- Stochastic Processes
- Sums of Squares
- Statistical Procedures
- F Test
- t Test, Independent Samples
- t Test, One Sample
- t Test, Paired Samples
- Accuracy in Parameter Estimation
- Analysis of Covariance
- Analysis of Variance
- Bartlett’s Test
- Barycentric Discriminant Analysis
- Behrens–Fisher t’ Statistic
- Bivariate Regression
- Bonferroni Procedure
- Bootstrapping
- Canonical Correlation Analysis
- Categorical Data Analysis
- Chi-Square Test
- Cluster Analysis
- Confirmatory Factor Analysis
- Contingency Table Analysis
- Contrast Analysis
- Descriptive Discriminant Analysis
- Diagnostic Classification Modeling
- Dummy Coding
- Duncan’s Multiple Range Test
- Dunnett’s Test
- Effect Coding
- Estimation
- Exploratory Factor Analysis
- Fisher’s Least Significant Difference Test
- Friedman Test
- Greenhouse–Geisser Correction
- Hidden Markov Model
- Hierarchical Linear Modeling
- Holm’s Sequential Bonferroni Procedure
- Jackknife
- Kolmogorov–Smirnov Test
- Kruskal–Wallis Test
- Latent Class Analysis
- Latent Growth Modeling
- Latent Profile Analysis
- Least Squares, Methods of
- Logistic Regression
- Mann–Whitney U Test
- Mauchly Test
- Maximum Likelihood Estimation
- McNemar’s Test
- Mean Comparisons
- Missing Data, Imputation of
- Multidimensional Scaling
- Multiple Comparison Tests
- Multiple Comparisons With Modeling Techniques
- Multiple Regression
- Multivariate Analysis of Variance
- Newman–Keuls Test
- Omnibus Tests
- Pairwise Comparisons
- Path Analysis
- Post Hoc Analysis
- Post Hoc Comparisons
- Predictive Discriminant Analysis
- Principal Components Analysis
- Propensity Score Analysis
- Scheffé Test
- Sequential Analysis
- Sign Test
- Stepwise Model Selection
- Stepwise Regression
- Structural Equation Modeling
- Survival Analysis
- Trend Analysis
- Tukey’s Honestly Significant Difference
- Welch’s t Test
- Wilcoxon Rank Sum Test
- Yates’s Correction
- Statistical Tests
- F Test
- t Test, Independent Samples
- t Test, One Sample
- t Test, Paired Samples
- z Test
- Bartlett’s Test
- Behrens–Fisher t’ Statistic
- Chi-Square Test
- Cochran–Armitage Test for Trend
- Duncan’s Multiple Range Test
- Dunnett’s Test
- Fisher’s Least Significant Difference Test
- Friedman Test
- Hosmer-Lemeshow Test
- Kolmogorov–Smirnov Test
- Kruskal–Wallis Test
- Mann–Whitney U Test
- Mauchly Test
- McNemar’s Test
- Multiple Comparison Tests
- Newman–Keuls Test
- Omnibus Tests
- Scheffé Test
- Sign Test
- Tukey’s Honestly Significant Difference
- Welch’s t Test
- Wilcoxon Rank Sum Test
- Structural Equation Modeling
- Theories, Laws, and Principles
- Central Limit Theorem
- Classical Test Theory
- Correspondence Principle
- Critical Theory
- Diffusion of Innovation Theory
- Falsifiability
- Game Theory
- Gauss–Markov Theorem
- Generalizability Theory
- Graph Theory
- Grounded Theory
- Item Response Theory
- Likelihood Principle
- Machine Learning
- Models
- Neural Networks
- Occam’s Razor
- Paradigm
- Positivism
- Postmodernism
- Probability, Laws of
- Social Capital Theory
- Social Support Theory
- Structural Paradigm
- Theory
- Theory of Attitude Measurement
- Toulmin Method
- Weber–Fechner Law
- Types of Variables
- Validity of Scores
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