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Allocation Concealment
In a randomized experiment, allocation concealment hides the sorting of trial participants into treatment groups so that this knowledge cannot be exploited. Adequate allocation concealment serves to prevent study participants from influencing treatment allocations for subjects. Studies with poor allocation concealment (or none at all) are prone to selection bias. Some standard methods of ensuring allocation concealment include sequentially numbered, opaque, sealed envelopes (SNOSE); sequentially numbered containers; pharmacy controlled randomization; and central randomization. CONSORT guidelines recommend that allocation concealment methods be included in a study's protocol, and that the allocation concealment methods be reported in detail in their publication; however, a 2005 study determined that most clinical trials have unclear allocation concealment in their protocols, in their publications, or both. A 2008 study of 146 meta-analyses concluded that the results of randomized cont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Randomized Experiment
In scientific method, science, randomized experiments are the experiments that allow the greatest reliability and validity of statistical estimates of treatment effects. Randomization-based inference is especially important in experimental design and in survey sampling. Overview In the statistical theory of design of experiments, randomization involves randomly allocating the experimental units across the treatment groups. For example, if an experiment compares a new drug against a standard drug, then the patients should be allocated to either the new drug or to the standard drug control using randomization. Randomized experimentation is ''not'' haphazard. Randomization reduces bias by equalising other factors that have not been explicitly accounted for in the experimental design (according to the law of large numbers). Randomization also produces ignorability, ignorable designs, which are valuable in statistical model, model-based statistical inference, especially Bayesian infe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selection Bias
Selection bias is the bias introduced by the selection of individuals, groups, or data for analysis in such a way that proper randomization is not achieved, thereby failing to ensure that the sample obtained is representative of the population intended to be analyzed. It is sometimes referred to as the selection effect. The phrase "selection bias" most often refers to the distortion of a statistical analysis, resulting from the method of collecting samples. If the selection bias is not taken into account, then some conclusions of the study may be false. Types of bias Sampling bias Sampling bias is systematic error due to a non-random sample of a population, causing some members of the population to be less likely to be included than others, resulting in a biased sample, defined as a statistical sample of a statistical population, population (or non-human factors) in which all participants are not equally balanced or objectively represented. It is mostly classified as a subtype of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CONSORT
__NOTOC__ Consort may refer to: Music * "The Consort" (Rufus Wainwright song), from the 2000 album ''Poses'' * Consort of instruments, term for instrumental ensembles * Consort song (musical), a characteristic English song form, late 16th–early 17th centuries Places * Consort, Alberta, a village in Alberta, Canada * Consort Islands, two small islands in the Dion Islands, Marguerite Bay, Antarctica * Consort Mountain, in the Victoria Cross Ranges, Alberta, Canada Titles * Royal consort, a spouse, concubine or companion, in particular the spouse of a reigning monarch: **Queen consort, wife of a reigning king ** Prince consort, husband of a reigning princess or queen ** King consort, rarely used alternative title for husband of a reigning queen ** Princess consort, wife of a reigning prince; also, rarely used alternative title for wife of a reigning king **Viceregal consort of Canada, spouse of the Governor General of Canada Other uses * Consolidated Standards of Reporting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clinical Trial Protocol
In natural and social science research, a protocol is most commonly a predefined procedural method in the design and implementation of an experiment. Protocols are written whenever it is desirable to standardize a laboratory method to ensure successful replication of results by others in the same laboratory or by other laboratories. Additionally, and by extension, protocols have the advantage of facilitating the assessment of experimental results through peer review. In addition to detailed procedures, equipment, and instruments, protocols will also contain study objectives, reasoning for experimental design, reasoning for chosen sample sizes, safety precautions, and how results were calculated and reported, including statistical analysis and any rules for predefining and documenting excluded data to avoid bias. Similarly, a protocol may refer to the procedural methods of health organizations, commercial laboratories, manufacturing plants, etc. to ensure their activities (e.g., ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meta-analysis
Meta-analysis is a method of synthesis of quantitative data from multiple independent studies addressing a common research question. An important part of this method involves computing a combined effect size across all of the studies. As such, this statistical approach involves extracting effect sizes and variance measures from various studies. By combining these effect sizes the statistical power is improved and can resolve uncertainties or discrepancies found in individual studies. Meta-analyses are integral in supporting research grant proposals, shaping treatment guidelines, and influencing health policies. They are also pivotal in summarizing existing research to guide future studies, thereby cementing their role as a fundamental methodology in metascience. Meta-analyses are often, but not always, important components of a systematic review. History The term "meta-analysis" was coined in 1976 by the statistician Gene V. Glass, Gene Glass, who stated ''"Meta-analysis refers t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Randomized Controlled Trials
A randomized controlled trial (or randomized control trial; RCT) is a form of scientific experiment used to control factors not under direct experimental control. Examples of RCTs are clinical trials that compare the effects of drugs, surgical techniques, medical devices, diagnostic procedures, diets or other medical treatments. Participants who enroll in RCTs differ from one another in known and unknown ways that can influence study outcomes, and yet cannot be directly controlled. By randomly allocating participants among compared treatments, an RCT enables ''statistical control'' over these influences. Provided it is designed well, conducted properly, and enrolls enough participants, an RCT may achieve sufficient control over these confounding factors to deliver a useful comparison of the treatments studied. Definition and examples An RCT in clinical research typically compares a proposed new treatment against an existing standard of care; these are then termed the 'exper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subjectivity
The distinction between subjectivity and objectivity is a basic idea of philosophy, particularly epistemology and metaphysics. Various understandings of this distinction have evolved through the work of countless philosophers over centuries. One basic distinction is: *Something is subjective if it is dependent on a mind (biases, perception, emotions, opinions, imagination, or conscious experience). Solomon, Robert C.br>"Subjectivity" in Honderich, Ted. '' Oxford Companion to Philosophy'' (Oxford University Press, 2005), p.900. If a claim is true exclusively when considering the claim from the viewpoint of a sentient being, it is subjectively true. For example, one person may consider the weather to be pleasantly warm, and another person may consider the same weather to be too hot; both views are subjective. *Something is objective if it can be confirmed independently of a mind. If a claim is true even when considering it outside the viewpoint of a sentient being, then it may be lab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blinded Experiment
In a blind or blinded experiment, information which may influence the participants of the experiment is withheld until after the experiment is complete. Good blinding can reduce or eliminate experimental biases that arise from a participants' expectations, observer's effect on the participants, observer bias, confirmation bias, and other sources. A blind can be imposed on any participant of an experiment, including subjects, researchers, technicians, data analysts, and evaluators. In some cases, while blinding would be useful, it is impossible or unethical. For example, it is not possible to blind a patient to their treatment in a physical therapy intervention. A good clinical protocol ensures that blinding is as effective as possible within ethical and practical constraints. During the course of an experiment, a participant becomes unblinded if they deduce or otherwise obtain information that has been masked to them. For example, a patient who experiences a side effect may corr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Design Of Experiments
The design of experiments (DOE), also known as experiment design or experimental design, is the design of any task that aims to describe and explain the variation of information under conditions that are hypothesized to reflect the variation. The term is generally associated with experiments in which the design introduces conditions that directly affect the variation, but may also refer to the design of quasi-experiments, in which natural conditions that influence the variation are selected for observation. In its simplest form, an experiment aims at predicting the outcome by introducing a change of the preconditions, which is represented by one or more independent variables, also referred to as "input variables" or "predictor variables." The change in one or more independent variables is generally hypothesized to result in a change in one or more dependent variables, also referred to as "output variables" or "response variables." The experimental design may also identify ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Randomized Experiment
In scientific method, science, randomized experiments are the experiments that allow the greatest reliability and validity of statistical estimates of treatment effects. Randomization-based inference is especially important in experimental design and in survey sampling. Overview In the statistical theory of design of experiments, randomization involves randomly allocating the experimental units across the treatment groups. For example, if an experiment compares a new drug against a standard drug, then the patients should be allocated to either the new drug or to the standard drug control using randomization. Randomized experimentation is ''not'' haphazard. Randomization reduces bias by equalising other factors that have not been explicitly accounted for in the experimental design (according to the law of large numbers). Randomization also produces ignorability, ignorable designs, which are valuable in statistical model, model-based statistical inference, especially Bayesian infe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metascience
Metascience (also known as meta-research) is the use of scientific methodology to study science itself. Metascience seeks to increase the quality of scientific research while reducing inefficiency. It is also known as "research on research" and "the science of science", as it uses research methods to study how research is done and find where improvements can be made. Metascience concerns itself with all fields of research and has been described as "a bird's eye view of science". In the words of John Ioannidis, "Science is the best thing that has happened to human beings... but we can do it better." In 1966, an early meta-research paper examined the statistical methods of 295 papers published in ten high-profile medical journals. It found that "in almost 73% of the reports read... conclusions were drawn when the justification for these conclusions was invalid." Meta-research in the following decades found many methodological flaws, inefficiencies, and poor practices in research ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
