Jediný katalog výzkumných metod — zjistěte, jak každá funguje, kdy ji použít a co nedokáže.
Proportional stratified sampling divides the target population into non-overlapping strata (subgroups defined by a key characteristic such as age band, region, or gender) and then draws a simple random sample from each stratum so that each stratum's share of the total sample matches its share of the total population. B
Proportional systematic sampling combines systematic (every k-th element) selection with proportional allocation across subgroups, ensuring that each stratum contributes sample units in proportion to its share of the total population. The result is an equal-probability design that is administratively simple, spreads th
Proportional weighted sampling is a probability-based survey design in which each subgroup (stratum or cluster) of the population is sampled and weighted in proportion to its true size in the population. By assigning sampling weights that mirror the actual composition of the population, the method ensures unbiased esti
Proprioceptive assessment is a bedside neurological examination evaluating the sense of joint position and movement, mediated by mechanoreceptors in muscles, tendons, and joints. Clinical testing of proprioception is essential for comprehensive neurological evaluation in conditions affecting sensory function, coordinat
The Prospective and Retrospective Memory Questionnaire (PRMQ) is a 16-item self-report instrument designed to measure subjective memory complaints across two distinct memory domains: prospective memory (remembering to do things in the future) and retrospective memory (remembering past events and information). Developed
Pruning response analysis systematically measures the morphological and physiological effects of pruning on fruit trees, including shoot development, branching architecture, flowering, fruit set, and yield. By combining visual assessment with growth measurements and phenological tracking, growers and researchers can qu
The Pruritus Visual Analog Scale (VAS) is a simple, single-item patient-administered tool measuring itch intensity on a continuous 0–10 (or 0–100) scale. Adapted from the original VAS for pain, it is one of the most frequently used outcome measures in dermatological research and clinical practice due to its simplicity,
The PsAQoL is a disease-specific patient-reported outcome measure of quality of life impact in psoriatic arthritis (PsA), a chronic inflammatory condition affecting joints and skin. Developed by McKenna and Doherty in 1997, PsAQoL comprises 20 items assessing the multidimensional impact of PsA on physical function, emo
The PSUS is a self-report questionnaire measuring compulsive smartphone use, withdrawal symptoms, and loss of control related to mobile devices. Developed by Hussain, Griffiths, and Sheffield in 2017, it targets the growing phenomenon of smartphone addiction in the digital age. The PSUS captures how smartphone dependen
The Psychological Capital Questionnaire (PCQ-24) measures psychological capital—the positive psychological resources of efficacy, hope, resilience, and optimism—that enable individuals to thrive in demanding work environments. Developed by Luthans, Youssef, and Avolio in 2007, it operationalizes a positive organization
The Psychological Safety Scale (PSS), developed by Amy Edmondson in 1999, measures team members' shared perception that they can take interpersonal risks—speaking up, asking questions, admitting mistakes, proposing new ideas—without fear of embarrassment, punishment, or rejection. The 7-item scale captures a team-level
The Psychosocial Safety Climate Scale (PSC-12) measures employees' perceptions of organizational commitment to protecting worker psychological health and preventing psychosocial hazards (stress, harassment, bullying). Developed by Dollard and Karasek, and refined by Bailey and colleagues, the PSC-12 captures four dimen
The PTSD Checklist for DSM-5 (PCL-5) is a 20-item self-report measure of posttraumatic stress disorder (PTSD) symptoms aligned with DSM-5 diagnostic criteria. Developed by Weathers, Litz, and Keane, it is the gold standard screening and outcome measure for PTSD in military, veteran, and civilian trauma populations. The
The PCL-M is a 17-item self-report inventory measuring PTSD symptom severity in military personnel. Developed by Weathers and colleagues in 1993, it directly corresponds to DSM-IV diagnostic criteria. It is widely used in military, veteran, and trauma-exposed populations for screening and monitoring treatment response.
The Public Service Motivation Scale (PSMS), developed by Perry (1996) and refined by Kim et al. (2013), measures the intrinsic motivation of public sector employees to serve the public interest, contribute to civic good, feel compassion for others, and make self-sacrifices for collective benefit. Public service motivat
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 constricts (miosis) during relaxation or withdrawal. First documented systematically b
Purposive sampling is a non-probability strategy in which the researcher deliberately selects participants, documents, or cases that are information-rich with respect to the research question. Rather than drawing units at random, the researcher applies explicit criteria aligned with the study's purpose, maximising the
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 1935, it uses Q-sorts—where participants rank statements on a continuum—to meas
The Questionnaire of Olfactory Disorders (QOD) is a self-report instrument assessing the subjective impact of olfactory dysfunction on quality of life and daily functioning. Derived from olfactory research standardized testing (Sniffin' Sticks) and adapted for clinical use, the QOD measures perceived smell loss, change
The QOLCE is a comprehensive 76-item disease-specific instrument developed by Sabaz et al. in 2000 to assess quality of life in children with epilepsy aged 4–16 years. Measuring across 16 distinct domains including seizure worry, cognitive concerns, medication effects, school/peer functioning, and family impact, the QO
The QOLIE-89 is a comprehensive disease-specific quality-of-life instrument developed specifically for people with epilepsy. Introduced by Devinsky and colleagues in 1995, it captures the broad impact of epilepsy on physical, emotional, social, and cognitive functioning. With 89 items organized into 17 distinct domains
The Quick Sequential Organ Failure Assessment (qSOFA) score, introduced by the Sepsis-3 taskforce in 2016, is a rapid 3-variable bedside screening tool for identifying non-ICU patients at high risk of sepsis-related mortality. It uses altered mentation, systolic hypotension, and tachypnea to quickly stratify patients w
The QSU-Brief is a 10-item self-report instrument that rapidly assesses the intensity of craving for cigarettes and the intention to smoke. Developed by Cox, Tiffany, and Christen in 1996, it is a brief version of the longer Questionnaire on Smoking Urges (QSU) and is widely used in smoking cessation treatment and rese
Quantitative Descriptive Analysis (QDA) is a comprehensive sensory evaluation method developed by Stone and colleagues in the 1970s that uses a trained panel to describe the intensity of sensory attributes in food products. QDA provides detailed, quantitative profiles of flavor, aroma, texture, and appearance, allowing
Quantitative Susceptibility Mapping (QSM) is a post-processing technique that converts MRI phase data into quantitative susceptibility values, enabling direct visualization and measurement of tissue magnetic properties. Developed by Wang, Liu, and colleagues, QSM transforms phase shifts caused by differences in magneti
Query optimization is a critical process in database management that transforms high-level SQL queries into efficient execution plans. Developed systematically by IBM researchers in the late 1970s, it aims to minimize execution time, disk I/O, and resource consumption by selecting the most effective access paths and jo
The Quest Scale, developed by Batson and Ventis (1976), is a 12-item self-report measure of a third religious orientation beyond Allport and Ross's intrinsic and extrinsic religiosity. The 'quest' orientation reflects an open, questioning approach to religion: someone who views faith as an ongoing journey of exploratio
The Questionnaire about the Process of Recovery (QPR), also called the 'Neil-QPR,' is a 22-item self-report measure assessing subjective recovery processes in individuals with serious mental illness, particularly schizophrenia and related disorders. Developed by Stephen T. Neil, Matthias Kilbride, Leonie Pitt, and coll
Quota sampling is a non-probability technique in which the researcher pre-specifies how many units to recruit from each subgroup (quota cell) defined by one or more control variables such as age, gender, or occupation. Interviewers or data collectors then use their own judgment to find and enroll participants until eac
The Racism and Life Experiences Scales (RaLES) are a multidimensional assessment designed to measure the frequency and intensity of racism-related stress experienced by people of color. Developed by Harrell in 2000, the RaLES operationalize racism not as a single phenomenon but as a constellation of stressors across mu
Radiographic assessment is a systematic diagnostic imaging method using X-rays to create two-dimensional images of internal structures, facilitating detection of skeletal, thoracic, and abdominal pathology. Since the discovery of X-rays in 1896 and their early adoption in veterinary medicine, radiography has remained f
Radioimmunoassay (RIA) is a highly sensitive, quantitative laboratory technique that measures the concentration of a specific antigen — such as a hormone, drug, or pathogen-derived protein — in a biological sample by exploiting competitive binding between a radiolabelled antigen and the sample antigen for a limited sup
Radiomics is a computational methodology that extracts large numbers of quantitative features from medical images (CT, MRI, PET) using automated image analysis and machine learning to discover imaging biomarkers associated with disease phenotype, prognosis, and treatment response. Developed by Lambin, Gillies, and coll
Goniometry is the standardized clinical measurement of joint angles using a goniometer (angle-measuring instrument) to quantify range of motion in degrees. Developed from orthopedic assessment traditions, goniometric measurement is a fundamental skill in physical therapy, occupational therapy, and orthopedic medicine f
Ranked Set Sampling (RSS) is a data collection method introduced by G. A. McIntyre in 1952 that improves estimation efficiency when visual ranking of units is easier or cheaper than actual measurement. By deliberately selecting and measuring units that are ranked as most likely to yield desired outcomes, RSS reduces va
The Rasch model, introduced by Georg Rasch in 1960, is the simplest member of the Item Response Theory (IRT) family. It assigns a single difficulty parameter to each test item and places both item difficulties and person abilities on the same logit scale, enabling direct, sample-independent comparison of items and pers
Rate of force development (RFD) is the speed at which force is produced during the initial phase of muscle contraction, typically expressed as the slope of the force-time curve in the first 50, 100, or 200 milliseconds of isometric contraction. Introduced comprehensively by Aagaard and colleagues (2002), RFD is a measu
The RCQ is a 12-item self-report instrument designed to assess an individual's stage of change motivation regarding substance use, particularly alcohol use. Developed by Rollnick and colleagues in 1992, it operationalizes the Transtheoretical Model of Change by measuring readiness across the precontemplation, contempla
Rigorous Coupled-Wave Analysis is a semi-analytical computational method for solving Maxwell's equations in periodic structures such as diffraction gratings and photonic crystals. Developed by Moharam and Gaylord in 1981, RCWA expands the electromagnetic fields in each periodic region into Fourier series and couples th
The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) is a comprehensive, evidence-based diagnostic system for identifying and classifying temporomandibular disorders (TMD)—a group of painful and functional conditions affecting the jaw joint, muscles of mastication, and related structures. Original
Rotating Disk Electrode (RDE) electrochemistry combined with Koutecky-Levich analysis is a powerful electrochemical technique that decouples diffusion-limited and kinetically limited electron-transfer processes. Developed by Levich in the 1960s, RDE enables determination of heterogeneous electron-transfer rate constant
The reactive strength index (RSI) is a measure of lower-body reactive strength and elastic energy utilization, calculated as jump height divided by the contact time between landing from a drop and takeoff. Introduced by Bobbert and colleagues (1987), RSI quantifies the efficiency of the stretch-shortening cycle (SSC)—t
Real-World Evidence (RWE) is clinical evidence derived from Real-World Data (RWD)—data routinely collected in clinical practice from electronic health records, insurance claims, patient registries, and other healthcare sources. Formalized by the FDA in 2016 (Sherman et al.), RWE addresses a critical gap: while randomiz
Receiver Function (RF) analysis is a seismic method that isolates P-to-S wave conversions at crustal and mantle discontinuities using teleseismic records from distant earthquakes. Introduced by Langston in 1979, RF analysis provides a cost-effective way to determine crustal thickness, Poisson's ratio, and upper mantle
The Recovery Assessment Scale (RAS) is a 41-item self-report measure designed to assess personal recovery in individuals with serious mental illness. Developed by Corrigan and colleagues in 2004, it captures the subjective and multidimensional nature of recovery, including hope, autonomy, goal achievement, and symptom
The Recovery Experience Questionnaire (REQ) is an assessment tool measuring the quality and dimensions of off-work recovery from occupational stress. Developed by Sonnentag and Fritz in 2007, the REQ evaluates four key recovery experiences: psychological detachment from work, relaxation, mastery, and control. The instr
The Recovery-Oriented Practices Index (ROPI) is a measure assessing the degree to which mental health services and programs embody recovery-oriented principles and practices. Developed by Sanja P. Barbic, Trevor Krupa, and Inge Armstrong in 2009, the ROPI evaluates whether services prioritize consumer choice, hope, aut
Recrystallization is a classical purification technique in which a solid compound is dissolved in hot solvent, then allowed to crystallize upon cooling, yielding pure crystals while impurities remain in solution. Practiced for centuries in chemistry laboratories, recrystallization remains one of the most effective and
Redox reaction mechanism analysis is the systematic study of electron transfer pathways in oxidation-reduction reactions. Formalized by Rudolph Marcus in the 1950s (earning him the Nobel Prize in 1992), this framework explains how electrons move between reactants, what factors control reaction rates, and how electronic
Redundancy Analysis (RDA) is a multivariate technique developed by van den Wollenberg (1977) that combines multiple regression and principal component analysis. RDA finds linear combinations of predictor variables that best predict variation in response variables, making it ideal for understanding how sets of predictor
Regional Homogeneity (ReHo) is a measure of synchronization between a voxel and its spatial neighbors in resting-state fMRI. Introduced by Zang and colleagues in 2004, ReHo quantifies local within-cluster activity coherence, reflecting the degree to which brain regions exhibit synchronized spontaneous activity at rest.
Registry-based research uses systematically collected clinical data from patient registries—organized databases of patients with a specific disease or condition—to conduct observational studies. Registries began in the mid-20th century but have proliferated since the 2000s as electronic health records expanded and fund
The Reintegration to Normal Living Index (RNLI) is a brief, patient-report measure designed to assess how completely a person has returned to 'normal' community living following a major health event (stroke, head injury, cardiac event, or other condition requiring significant recovery). Developed by Wood-Dauphinee and
The RSQ is an 18-item self-report measure of rejection sensitivity—the disposition to anxiously expect, readily perceive, and intensely react to rejection from others. Developed by Downey and Feldman in 1996, it captures both anxiety about rejection and expectancy of rejection. Rejection sensitivity is recognized as tr
The Relationship Assessment Scale is a brief, widely used instrument for measuring global relationship satisfaction and quality in romantic partnerships. Developed by Susan Hendrick in 1988 and based on Robert Sternberg's Triangular Theory of Love, the RAS measures the three core components of love: intimacy (emotional
Statistical reliability analysis models the time-to-failure of components, systems, or products using parametric lifetime distributions fitted to observed or censored failure data. Formalized comprehensively by William Q. Meeker and Luis A. Escobar in their 1998 Wiley monograph, the framework integrates maximum likelih
The Remote Delphi Technique applies the structured iterative consensus process of the classic Delphi method entirely through remote communication channels — email, web-based survey platforms, or dedicated collaboration tools — eliminating the need for geographic co-presence. Experts complete successive questionnaire ro
Remote Document Collection is a data collection technique in which researchers gather written, visual, or multimedia documents from digital sources — online archives, institutional repositories, cloud storage, email, or government databases — without requiring physical presence. It extends classical document analysis i
A Remote Focus Group is a synchronous, moderated group discussion conducted via video or audio conferencing rather than in a shared physical space. Participants — typically 5 to 10 people — join from separate locations and discuss a topic guided by a trained moderator. The method preserves the core strengths of in-pers
Remote non-participant observation is a qualitative data collection technique in which the researcher observes naturally occurring behavior, interaction, or activity from a distance — via video conferencing platforms, live-streamed sessions, online communities, or recorded media — without joining or influencing the set