Statistics — Page 51
Explore statistical methods, their assumptions, interpretation and limitations.
Research field
Method family
Price Elasticity from Scanner Data
Estimating price elasticity from scanner data means fitting a store-level sales-response model to the weekly unit-sales, price, and promotion records that retail checkout scanners generate, in order to recover how sensitive demand is to pri...
Principal Component Risk Factors
Risk Factor PCA is a dimension-reduction method that decomposes the return covariance matrix of many assets into a small set of orthogonal principal components interpreted as systematic risk factors. Litterman and Scheinkman (1991) used it...
Probit Model
The probit model is a regression method for a binary (0/1) outcome that maps a linear index of the predictors through the standard normal cumulative distribution function to produce a probability. It is a classical discrete-choice alternati...
Process Tracing
Process Tracing is a qualitative research method developed by George and Bennett (2005) for studying causal mechanisms and causal chains within individual cases. It involves examining the sequence of events and decision-making processes wit...
Propensity Score Matching in Education Research
Propensity Score Matching (PSM) in education research is a quasi-experimental technique that creates comparable treatment and control groups from observational student, teacher, or school data. By balancing groups on observed background cha...
Propensity Score Weighting
Propensity score weighting is a causal-inference method that reweights observations so that the covariate distributions of treated and untreated units look exchangeable, enabling unbiased estimation of average treatment effects from observa...
Propensity Score Weighting in Education Research
Propensity score weighting (PSW) is a quasi-experimental technique that reweights observational samples so that treated and comparison students look similar on measured background characteristics, allowing credible causal estimates of educa...
Prophet
Prophet is a Bayesian structural time series model introduced by Taylor and Letham at Facebook/Meta in 2018. It forecasts a continuous series by decomposing it into separate, interpretable trend, seasonality, and holiday components, and is...
Proportion Test
The proportion test (z-test for proportions) is a parametric hypothesis test that compares one or two sample proportions against a reference value or each other. Grounded in the large-sample normal approximation formalized by Fleiss, Levin,...
Prospective Old-Age Dependency Ratio
The prospective old-age dependency ratio (POADR) is a measure of population aging that redefines the onset of old age in terms of remaining life expectancy rather than a fixed chronological age such as 65. Proposed by Warren Sanderson and S...
Psychological Capital Scale
Psychological capital (PsyCap) is a higher-order positive psychological resource in the positive-organizational-behavior tradition, composed of four state-like capacities: hope, efficacy (self-confidence), resilience, and optimism — togethe...
Psychological Contract Measurement
The psychological contract is an employee's set of beliefs about the reciprocal obligations between themselves and their employer — the unwritten promises that go beyond the formal employment agreement. Denise Rousseau revived and reframed...
Psychological Empowerment Scale
The Psychological Empowerment Scale is Gretchen Spreitzer's measure of empowerment as an internal motivational state, defined by four cognitions: meaning, competence, self-determination, and impact. It operationalizes the interpretive model...
Psychosocial Impact of Assistive Devices Scale
The Psychosocial Impact of Assistive Devices Scale (PIADS) measures how an assistive device affects a user's quality of life, not whether they are satisfied with it or what it lets them physically do. Developed by Jeffrey Jutai and Hy Day,...
Publication Bias Analysis
Publication bias analysis examines whether the set of studies included in a meta-analysis is a representative sample of all conducted research, or whether studies with non-significant or unfavorable results have been systematically suppress...
Pupillometry
Pupillometry is the measurement of changes in pupil size in response to cognitive, emotional, or perceptual stimuli. The pupil automatically dilates (mydriasis) during mental effort, emotional arousal, or approach-related states, and constr...
Q-Methodology
Q-Methodology is a mixed-methods approach that combines quantitative factor analysis with qualitative interpretation to identify distinct perspectives, viewpoints, or 'factors' shared by groups of people. Introduced by William Stephenson in...
QARDL
QARDL (Quantile Autoregressive Distributed Lag) combines quantile regression with ARDL modeling to estimate conditional relationships at different points of the distribution, revealing heterogeneous short-run and long-run effects. Introduce...
Quadratic Discriminant Analysis
Quadratic discriminant analysis is a generative classifier that models each class with its own multivariate Gaussian distribution, allowing each class a separate covariance matrix. Unlike linear discriminant analysis, which assumes a shared...
Quandt-Andrews Test
The Quandt-Andrews test, formalized by Andrews (1993), detects structural breaks in regression parameters when the breakpoint date is unknown a priori. It sweeps all candidate break dates within a trimmed interior of the sample, computes a...
Quantile Regression
Quantile regression models conditional quantiles of an outcome - the median, the 25th or 75th percentile, and so on - rather than the conditional mean that OLS targets. Introduced by Koenker and Bassett in 1978, it reveals how predictors ac...
Quantile VAR
Quantile VAR estimates impulse responses of multivariate systems conditional on different quantiles of the distribution, revealing how shocks propagate heterogeneously across the conditional distribution. Introduced by Koenker and Xiao (200...
Quantile-on-Quantile Regression
Quantile-on-quantile regression is a nonparametric technique that estimates how the quantiles of one variable depend on the quantiles of another. By combining standard quantile regression with local linear smoothing, it produces a full two-...
Quebec User Evaluation of Satisfaction with Assistive Technology
The Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST 2.0) is a standardized outcome measure that quantifies how satisfied a user is with an assistive device and with the services surrounding it. Developed by Louise De...