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Self-selection
In statistics, self-selection bias arises in any situation in which individuals select themselves into a group, causing a biased sample with nonprobability sampling. It is commonly used to describe situations where the characteristics of the people which cause them to select themselves in the group create abnormal or undesirable conditions in the group. It is closely related to the non-response bias, describing when the group of people responding has different responses than the group of people not responding. Self-selection bias is a major problem in research in sociology, psychology, economics and many other social sciences. In such fields, a poll suffering from such bias is termed a self-selected listener opinion poll or "SLOP". The term is also used in criminology to describe the process by which specific predispositions may lead an offender to choose a criminal career and lifestyle. While the effects of self-selection bias are closely related to those of selection bias, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roy Model
The Roy model is one of the earliest works in economics on self-selection due to A. D. Roy. The basic model considers two types of workers that choose occupation in one of two sectors. Original model Roy's original paper deals with workers selecting into fishing and hunting professions, where there is no uncertainty about the amount of goods (fish or rabbits) that will be caught in a given period, but fishing is more costly as it requires more skill. The central question that Roy tries to answer in the original paper is whether the best hunters will hunt, and the best fishermen will fish. While the discussion is non-mathematical, it is observed that choices will depend on the distribution of skills, the correlation between these skills in the population, and the technology available to use these skills. Further developments George Borjas was the first to formalize the model of Roy in a mathematical sense and apply it to self-selection in immigration. Specifically, assume source co ... [...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] |
Psychology
Psychology is the scientific study of mind and behavior. Its subject matter includes the behavior of humans and nonhumans, both consciousness, conscious and Unconscious mind, unconscious phenomena, and mental processes such as thoughts, feelings, and motivation, motives. Psychology is an academic discipline of immense scope, crossing the boundaries between the Natural science, natural and social sciences. Biological psychologists seek an understanding of the Emergence, emergent properties of brains, linking the discipline to neuroscience. As social scientists, psychologists aim to understand the behavior of individuals and groups.Hockenbury & Hockenbury. Psychology. Worth Publishers, 2010. A professional practitioner or researcher involved in the discipline is called a psychologist. Some psychologists can also be classified as Behavioural sciences, behavioral or Cognitive science, cognitive scientists. Some psychologists attempt to understand the role of mental functions in i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Program Evaluation
Program evaluation is a systematic method for collecting, analyzing, and using information to answer questions about projects, policies and programs, particularly about their effectiveness and efficiency. In the public, private, and voluntary sector, stakeholders might be required to assess—under law or charter—or want to know whether the programs they are funding, implementing, voting for, receiving or opposing are producing the promised effect. To some degree, program evaluation falls under traditional cost–benefit analysis, concerning fair returns on the outlay of economic and other assets; however, social outcomes can be more complex to assess than market outcomes, and a different skillset is required. Considerations include how much the program costs per participant, program impact, how the program could be improved, whether there are better alternatives, if there are unforeseen consequences, and whether the program goals are appropriate and useful. Evaluators h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Causation (sociology)
Causation refers to the existence of " cause and effect" relationships between multiple variables. Causation presumes that variables, which act in a predictable manner, can produce change in related variables and that this relationship can be deduced through direct and repeated observation. Theories of causation underpin social research as it aims to deduce causal relationships between structural phenomena and individuals and explain these relationships through the application and development of theory. Due to divergence amongst theoretical and methodological approaches, different theories, namely functionalism, all maintain varying conceptions on the nature of causality and causal relationships. Similarly, a multiplicity of causes have led to the distinction between necessary and sufficient causes. Logical formulation of the causal relationship - A and B represent some form of phenomena (either concrete or abstract), - A is statistically related to B in so far as an observed c ... [...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] |
Sampling Bias
In statistics, sampling bias is a bias (statistics), bias in which a sample is collected in such a way that some members of the intended statistical population, population have a lower or higher sampling probability than others. It results in a biased sample of a population (or non-human factors) in which all individuals, or instances, were not equally likely to have been selected. If this is not accounted for, results can be erroneously attributed to the phenomenon under study rather than to the method of sampling (statistics), sampling. Medical sources sometimes refer to sampling bias as ascertainment bias. Ascertainment bias has basically the same definition, but is still sometimes classified as a separate type of bias. Distinction from selection bias Sampling bias is usually classified as a subtype of selection bias, sometimes specifically termed sample selection bias, but some classify it as a separate type of bias. A distinction, albeit not universally accepted, of samplin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convenience Sampling
Convenience sampling (also known as grab sampling, accidental sampling, or opportunity sampling) is a type of non-probability sampling that involves the sample being drawn from that part of the population that is close to hand. Convenience sampling is not often recommended by official statistical agencies for research due to the possibility of sampling error and lack of representation of the population. It can be useful in some situations, for example, where convenience sampling is the only possible option. A trade off exists between this method of quick sampling and accuracy. Collected samples may not represent the population of interest and can be a source of bias, with larger sample sizes reducing the chance of sampling error occurring. Advantages Convenience sampling can be used by almost anyone and has been around for generations. One of the reasons that it is most often used is due to the numerous advantages it provides. This method is extremely speedy, easy, readily ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Market Research
Market research is an organized effort to gather information about target markets and customers. It involves understanding who they are and what they need. It is an important component of business strategy and a major factor in maintaining competitiveness. Market research helps to identify and analyze the needs of the market, the market size and the competition. Its techniques encompass both qualitative techniques such as focus groups, in-depth interviews, and ethnography, as well as quantitative techniques such as customer surveys, and analysis of secondary data. It includes social and opinion research, and is the systematic gathering and interpretation of information about individuals or organizations using statistical and analytical methods and techniques of the applied social sciences to gain insight or support decision making. Market research, marketing research, and marketing are a sequence of business activities; sometimes these are handled informally. The field of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Statistics
Statistics (from German language, German: ', "description of a State (polity), state, a country") is the discipline that concerns the collection, organization, analysis, interpretation, and presentation of data. In applying statistics to a scientific, industrial, or social problem, it is conventional to begin with a statistical population or a statistical model to be studied. Populations can be diverse groups of people or objects such as "all people living in a country" or "every atom composing a crystal". Statistics deals with every aspect of data, including the planning of data collection in terms of the design of statistical survey, surveys and experimental design, experiments. When census data (comprising every member of the target population) cannot be collected, statisticians collect data by developing specific experiment designs and survey sample (statistics), samples. Representative sampling assures that inferences and conclusions can reasonably extend from the sample ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Group (sociology)
In the social sciences, a social group is defined as two or more people who interact with one another, share similar characteristics, and collectively have a sense of unity. Regardless, social groups come in a myriad of sizes and varieties. For example, a society can be viewed as a large social group. The system of behaviors and psychological processes occurring within a social group or between social groups is known as group dynamics. Definition Social cohesion approach A social group exhibits some degree of social cohesion and is more than a simple collection or aggregate of individuals, such as people waiting at a bus stop, or people waiting in a line. Characteristics shared by members of a group may include Interest (emotion), interests, Value (personal and cultural), values, Social representation, representations, ethnic or social background, and kinship ties. Kinship ties being a social bond based on common ancestry, marriage or adoption. In a similar vein, some rese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
