Explore science by method, field &amp; evidence.

AB Design

The AB design is the simplest single-subject experimental design, consisting of two sequential phases: a baseline phase (A) in which the target behavior is observed under natural conditions without intervention, followed by an intervention phase (B) in which the treatment or manipulation is introduced. Changes in the b

2 sources1960

ABA Design

The ABA design is a single-subject experimental design that demonstrates experimental control through three sequential phases: a baseline phase (A1), an intervention phase (B), and a return-to-baseline withdrawal phase (A2). By removing the intervention in the final phase and observing whether behavior reverts toward b

science technology studies

ABAB design

The ABAB design is a single-subject experimental methodology that establishes causal control by repeatedly introducing and removing an intervention. A baseline phase (A) is followed by an intervention phase (B), then a return to baseline (A), and a second intervention phase (B), allowing the researcher to demonstrate t

2 sources1960

linguistics

Acceptability Judgment Task

The acceptability judgment task is the modern, quantified successor to informal grammaticality judgments: instead of a single linguist marking a sentence grammatical or not, many participants rate carefully controlled sentences on a graded scale, and the ratings are analyzed statistically. Built on factorial designs wi

3 sources1996

disability studies

Accessibility Audit

An accessibility audit is a systematic survey of a built environment that measures its features against accessibility standards or codes to identify, classify, and prioritize barriers facing disabled people. The auditor inspects elements along the chain of use—approach and parking, the entrance, internal circulation, s

2 sources2001

public administration

Accountability Mechanism Analysis

Accountability mechanism analysis provides a structured way to identify, describe and evaluate the relationships through which public actors must explain and justify their conduct to others. Mark Bovens, in his 2007 conceptual framework, defines accountability narrowly as a relationship in which an actor has an obligat

2 sources2007

qualitative research

Action Research

Action research is a collaborative research methodology in which researchers work with practitioners and community members to investigate a problem, implement change, and evaluate outcomes, cycling through reflection, action, and learning. Developed by Kurt Lewin (1946), action research bridges research and practice, a

3 sources1946

Actor-Network Theory Analysis

Actor-Network Theory analysis treats society and technology as a single woven fabric, mapping how heterogeneous human and non-human actors—engineers, scallops, documents, machines, regulators—are linked into networks through a process of translation. Rather than explaining technical outcomes by appeal to pre-given soci

2 sources1984

Adaptive AB Design

The adaptive AB design is a single-subject experimental design that retains the two-phase baseline-then-intervention structure of the classic AB design but replaces fixed session-count rules with pre-specified data-driven criteria — such as stability thresholds or trend benchmarks — that determine when to transition be

Adaptive ABA Design

The Adaptive ABA Design is a single-subject experimental framework that follows the classic three-phase ABA withdrawal structure — baseline (A1), intervention (B), and return-to-baseline (A2) — while embedding prospective decision rules that allow researchers or clinicians to extend, shorten, or otherwise modify each p

Adaptive ABAB Design

The Adaptive ABAB Design is a single-subject experimental methodology that extends the classic ABAB reversal design by incorporating data-driven, prospective decision rules to determine when to transition between baseline (A) and intervention (B) phases. Rather than fixing phase lengths in advance, the researcher uses

2 sources1984

environmental sociology

Adaptive Capacity Assessment

Adaptive capacity assessment evaluates the ability of a community, sector, or system to adjust to climate variability and change, to moderate harm, and to seize opportunities. It is the third and most actionable component of the IPCC vulnerability framework, the part that captures why two equally exposed and sensitive

2 sources2006

Adaptive Clinical Trial Design

Adaptive clinical trial design is a flexible experimental framework, formalised by Bauer and Köhne in 1994, in which pre-specified rules allow the trial to be modified mid-course — adjusting sample size, treatment arms, or randomisation ratios — based on accumulating interim data while rigorously controlling the Type I

2 sources1994

Adaptive Control Group Experimental Design

An adaptive control group experimental design is an experiment that assigns participants to at least one treatment arm and one concurrent control group, while allowing pre-specified modifications to the trial — such as sample size re-estimation, early stopping, or allocation ratio changes — based on accumulating data.

2 sources1994

Adaptive Experiment

An adaptive experiment is an experimental design in which pre-specified rules allow the protocol to be modified — such as reallocating participants to better-performing arms, stopping early for efficacy or futility, or changing sample size — based on accumulating interim data, while maintaining statistical validity. Ad

2 sources1940

Adaptive Field Experiment

An adaptive field experiment is a randomized study conducted in a real-world environment in which pre-specified decision rules allow the researcher to modify the trial as interim data accumulate — for example, by reallocating participants toward more effective arms, adjusting sample size, or stopping early for efficacy

2 sources1990

Adaptive Fractional Factorial Experiment

An adaptive fractional factorial experiment combines the resource-efficiency of fractional factorial designs with a sequential, data-driven strategy for selecting which factors and interactions to investigate next. Rather than committing all experimental runs upfront, the researcher analyses results from an initial fra

2 sources1950

Adaptive Full Factorial Experiment

An adaptive full factorial experiment is an experimental design that starts with a complete crossing of all factors and all their levels, then uses interim data to modify subsequent runs — dropping unpromising factor levels, adding new ones, or re-allocating replication — while preserving the full factorial structure w

2 sources1950

Adaptive Laboratory Experiment

An adaptive laboratory experiment is a controlled experimental design conducted in a laboratory setting where pre-specified decision rules allow modifications to the study — such as sample size, treatment allocation, or stopping criteria — based on accumulating data. Unlike fixed designs, adaptive designs incorporate p

2 sources1947

Adaptive Multi-Arm Experiment

An adaptive multi-arm experiment simultaneously evaluates several treatment conditions against a common control and modifies the trial in real time based on accumulating data — dropping ineffective arms early, reallocating participants toward promising ones, or adjusting sample sizes — all while controlling error rates

Adaptive Multiple Baseline Design

The Adaptive Multiple Baseline Design is a single-case experimental design that applies the standard multiple baseline logic — staggering intervention onset across two or more tiers (behaviors, settings, or participants) — but allows phase-change decisions to be guided by ongoing data review rather than fixed, pre-spec

Adaptive Natural Experiment

An adaptive natural experiment combines the causal logic of the natural experiment — exploiting real-world events that assign individuals to conditions in a plausibly exogenous way — with pre-specified adaptive monitoring rules that allow the analytic protocol to be modified based on accumulating data. This hybrid desi

Adaptive Pretest-Posttest Experimental Design

An adaptive pretest-posttest experimental design measures all participants before and after an intervention while allowing pre-specified modifications to the trial — such as sample size re-estimation, treatment arm dropping, or randomization ratio adjustment — based on accumulated interim data. It combines the interpre

Adaptive Randomized Controlled Trial

An adaptive randomized controlled trial (adaptive RCT) is an experimental design in which pre-specified rules allow modifications to the trial while it is ongoing — such as changing allocation ratios, dropping underperforming arms, or stopping early for efficacy or futility — based on accumulating interim data. These a

2 sources1980

Adaptive Single-Subject Experimental Design

Adaptive single-subject experimental design (adaptive SSED) is an experimental methodology in which a single participant or unit is repeatedly observed under systematically alternated conditions — baseline and intervention — while pre-specified decision rules allow the researcher or clinician to modify treatment parame

2 sources1960

Adaptive Solomon Four-Group Design

The Adaptive Solomon Four-Group Design combines the pretest-sensitization control of Solomon's classic four-group structure with response-adaptive randomization, allowing interim outcome data to update the allocation probabilities across the four groups as the study progresses. This hybrid preserves the design's abilit

2 sources1949

public administration

Administrative Burden Analysis

Administrative burden analysis examines the costs that individuals experience when they interact with the state to claim benefits, comply with obligations or access public services. Articulated by Donald Moynihan, Pamela Herd and Hope Harvey in their influential 2015 article, the framework decomposes these costs into t

1 source2015

public policy

Advocacy Coalition Framework

The Advocacy Coalition Framework (ACF) is a theory of the policy process developed by Paul Sabatier and Hank Jenkins-Smith from the late 1980s and consolidated in their 1993 volume Policy Change and Learning. It explains policy stability and change over long periods by analysing competing coalitions of actors within a

1 source1993

organizational behavior

Affective Events Theory

Affective Events Theory (AET) is the macro framework that reoriented organizational research toward emotions and the events that cause them. Proposed by Howard Weiss and Russell Cropanzano in 1996, it argues that features of the work environment give rise to discrete events — daily hassles and uplifts — that trigger af

2 sources1996

religious studies

Agency Detection Task

The agency detection task is an experimental method in the cognitive science of religion that measures the human tendency to attribute ambiguous events to intentional agents - a tendency Justin Barrett named the Hyperactive (or Hypersensitive) Agency Detection Device, or HADD. Building on Stewart Guthrie's argument tha

science technology studies

media studies

Agenda-Setting Analysis

Agenda-Setting Analysis is an empirical method for investigating the influence of media coverage on what issues the public considers important. Developed by Maxwell McCombs and Donald Shaw (1972), the approach tests a core hypothesis about media effects: media coverage does not tell people what to think, but rather wha

4 sources1972

food agriculture studies

Agrifood Value Chain Analysis

Agrifood value chain analysis traces a food product through the full sequence of value-adding activities — from input supply and farming through processing, trade, and retail to the final consumer — and asks how value, costs, and power are distributed along that chain and where smallholders and processors can capture m

2 sources2001

food agriculture studies

Agroecosystem Analysis

Agroecosystem analysis (AEA) is a systems-diagnosis framework, formalized by Gordon Conway in 1987, that characterizes any agricultural system through four properties: productivity, stability, sustainability, and equitability. Rather than judging a farming system by yield alone, AEA treats the agroecosystem as an ecolo

2 sources1987

disability studies

Alternating Treatments Design

The alternating treatments design (ATD), also called the multielement design, is a single-case experimental method that rapidly alternates two or more conditions or treatments within a single individual to compare their effects directly. Rather than running each treatment in a long block, the analyst switches between c

1 source2013

political science

Anchoring Vignettes

Anchoring vignettes are a survey method for making self-assessments comparable across people and cultures. When respondents are asked to rate their own political efficacy, health, or freedom on an ordinal scale, different groups interpret the scale differently — what one culture calls 'a lot of freedom' another calls '

2 sources2004

archaeology

Ancient DNA Analysis

Ancient DNA analysis recovers genetic information from the degraded remains of past organisms — human and animal bones and teeth, and increasingly sediments — and uses it to reconstruct kinship, ancestry, population history, sex, pathogens, and domestication. Because DNA fragments into ever-shorter pieces and accumulat

2 sources2004

anthropology

Anthropological Household Survey

An anthropological household survey is a structured or semi-structured, census-style instrument administered to the households of a community to record their composition, economy, and assets in a standardized form. Taking the household rather than the individual as the unit of analysis, it captures who lives together,

1 source2017

Anticipatory Governance Analysis

Anticipatory governance is a framework for steering emerging technologies—nanotechnology, synthetic biology, AI—while their trajectories are still open, rather than waiting to react to harms after they have hardened. Developed by David Guston and colleagues at the Center for Nanotechnology in Society at Arizona State U

2 sources2008

linguistics

Apparent-Time Analysis

Apparent-time analysis is the foundational variationist method for detecting language change in progress without waiting for time to pass. Introduced by William Labov in his 1963 study of Martha's Vineyard, it compares the speech of speakers of different ages sampled at a single moment and treats the age dimension as a

3 sources1963

linguistics

Appraisal Analysis

Appraisal analysis is the systematic study of evaluative language — how speakers and writers express feelings, make judgements, value things, take a stance toward other voices, and turn the volume of their evaluations up or down. Developed by James Martin and Peter White within the interpersonal metafunction of systemi

2 sources2005

archaeology

Archaeobotanical Flotation

Archaeobotanical flotation is the standard recovery technique for charred plant macroremains, separating buoyant carbonized seeds, nutshell, and wood charcoal from archaeological sediment by agitating the soil in water. Because carbonized tissue is light and water-repellent, it rises and overflows into a fine mesh as a

field methods

Archaeological Stratigraphy

Archaeological stratigraphy is the systematic excavation and recording of soil layers, deposits, and features at an archaeological site in order to establish the relative chronological sequence of human activity. Grounded in the geological law of superposition — that lower layers are older than those above — it uses th

2 sources1973

archaeology

Archaeomagnetic Dating

Archaeomagnetic dating uses changes in Earth's magnetic field intensity and direction recorded in fired clay artifacts to determine age. Pioneered by Robert Coe in the 1960s, the method measures the magnetization of pottery and baked clay features, comparing measurements to a master curve of geomagnetic variation throu

library information science

historiography

Archival Content Analysis

Archival content analysis adapts the social-scientific technique of content analysis to the systematic study of historical documents held in archives. Where the impressionistic reading of sources risks privileging the vivid or the convenient, content analysis imposes an explicit, replicable procedure: a defined corpus,

2 sources1952

social psychology

Asch Conformity Paradigm

The Asch conformity paradigm, established by Solomon Asch in the 1950s, demonstrates the power of group pressure to make people publicly endorse a manifestly false judgment. A naive participant joins a group of confederates for a simple perceptual task -- matching the length of a standard line to one of three compariso

1 source1956

social work

Asset-Based Community Development

Asset-based community development (ABCD) is an approach to community practice that begins by identifying and mobilizing the strengths a community already possesses — the skills of its residents, the energy of its associations, and the resources of its institutions — rather than starting from a catalogue of its problems

2 sources1993

sport leisure studies

Athlete Career Transition Assessment

Athlete career transition assessment uses conceptual models of how athletes adapt to leaving sport to evaluate whether a given transition -- above all retirement -- is likely to be navigated healthily or to tip into crisis. Jim Taylor and Bruce Ogilvie's 1994 model of adaptation to retirement traces the whole process:

2 sources1994

communication

Audience Reception Analysis

Audience reception analysis studies how real audiences interpret and make meaning from media texts, rejecting the idea that meaning is simply transmitted from message to receiver. Built on Stuart Hall's encoding/decoding model and David Morley's empirical work, it treats interpretation as an active, socially situated p

2 sources1980

political science

Audit Experiment

An audit experiment, also called a correspondence or field audit study, sends matched but fictitious requests to real-world targets — such as legislators, landlords, or employers — while randomizing a single treatment cue, then compares the rate and quality of responses. In political science the canonical design follow

2 sources2011

media studies

Auteur Theory Analysis

Auteur Theory Analysis is a critical framework for studying cinema through the lens of directorial authorship, examining how individual directors express consistent themes, visual style, and ideological perspectives across multiple films. Developed by French critics of Cahiers du Cinéma (notably François Truffaut) and

4 sources1954

qualitative

Autoethnography

Autoethnography is a qualitative research method in which the researcher uses systematic self-reflection and personal narrative to examine their own experiences within a cultural, social, or organizational context. By treating the self as both subject and instrument, autoethnography connects individual lived experience

2 sources1979

qualitative

Axial Coding

Axial coding is the second major analytical step in grounded theory analysis, performed after open coding. Introduced by Anselm Strauss and Juliet Corbin in 1990, it involves systematically re-examining and reorganising the many discrete codes generated during open coding by identifying a central (axial) category and m

2 sources1990

disaster studies

Baseline Resilience Indicators for Communities

The Baseline Resilience Indicators for Communities (BRIC) is a composite-index method, introduced by Susan Cutter, Christopher Burton, and Christopher Emrich in 2010, for benchmarking the inherent, pre-event resilience of places to hazards and disasters. Rather than measuring how a community actually performed after a

2 sources2010

strategic management

BCG Growth-Share Matrix

The BCG growth-share matrix is a portfolio-analysis tool that classifies a diversified company's business units on two axes — the growth rate of their market and their market share relative to the largest competitor — and uses that classification to guide cash allocation across the portfolio. Devised by Bruce Henderson

2 sources1977

urban studies

Behavioral Mapping

Behavioral mapping is the systematic, time-sampled observation of how people actually occupy and move through a public space, recorded directly onto a plan of the site. Developed in the urban context by William H. Whyte's filmed studies of New York plazas and formalized into a public-life methodology by Jan Gehl, it pr

2 sources1980

environmental economics

Benefit Transfer Valuation

Benefit transfer is the practice of using economic value estimates from existing valuation studies to estimate the value of an environmental change at a new policy site where conducting a fresh primary study is not feasible. As systematized in Johnston, Rolfe, Rosenberger and Brouwer's 2015 guide, it ranges from simple

1 source2015

Berrypicking Evaluation

Marcia Bates's berrypicking model, introduced in her 1989 Online Review article 'The design of browsing and berrypicking techniques for the online search interface,' rejects the classic picture of information retrieval as a single query matched against a database to return one optimal set. Real searches, Bates argued,

1 source1989

food agriculture studies

Best-Worst Scaling of Food Values

Best-worst scaling of food values measures how much consumers care about a fixed set of food attributes — safety, price, taste, nutrition, naturalness, origin, environmental impact, fairness, and so on — by repeatedly asking them to pick the most and least important value from small subsets. Jayson Lusk and Brian Brigg

2 sources2009

qualitative

Biographical Research

Biographical research is a qualitative method that examines individual lives in depth — through life-history interviews, personal documents, letters, and autobiographical narratives — to understand how personal experience intersects with social, historical, and cultural forces. Rooted in Wilhelm Dilthey's hermeneutics

2 sources1883