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Validity (other)
Validity or Valid may refer to: Science/mathematics/statistics: * Validity (logic), a property of a logical argument * Scientific: ** Internal validity, the validity of causal inferences within scientific studies, usually based on experiments ** External validity, the validity of generalized causal inferences in scientific studies, usually based on experiments ** Valid name (zoology), in animal taxonomy ** Validly published name, in plant taxonomy * Validity (statistics), the application of the principles of statistics to arrive at valid conclusions ** Statistical conclusion validity, establishes the existence and strength of the co-variation between the cause and effect variables ** Test validity, validity in educational and psychological testing ** Face validity, the property of a test intended to measure something *** Construct validity, refers to whether a scale measures or correlates with the theorized psychological construct it measures *** Content validity, the extent to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Validity (logic)
In logic, specifically in deductive reasoning, an argument is valid if and only if it takes a form that makes it impossible for the premises to be true and the conclusion nevertheless to be false. It is not required for a valid argument to have premises that are actually true, but to have premises that, if they were true, would guarantee the truth of the argument's conclusion. Valid arguments must be clearly expressed by means of sentences called well-formed formulas (also called ''wffs'' or simply ''formulas''). The validity of an argument can be tested, proved or disproved, and depends on its logical form. Arguments In logic, an argument is a set of statements expressing the ''premises'' (whatever consists of empirical evidences and axiomatic truths) and an ''evidence-based conclusion.'' An argument is ''valid'' if and only if it would be contradictory for the conclusion to be false if all of the premises are true. Validity doesn't require the truth of the premises, ins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concurrent Validity
Concurrent validity is a type of evidence that can be gathered to defend the use of a test for predicting other outcomes. It is a parameter used in sociology, psychology, and other psychometric or behavioral sciences. Concurrent validity is demonstrated when a test correlates well with a measure that has previously been validated. The two measures may be for the same construct, but more often used for different, but presumably related, constructs. The two measures in the study are taken at the same time. This is in contrast to predictive validity, where one measure occurs earlier and is meant to predict some later measure.McIntire, S.A. and Miller, L.A., Foundations of Psychological Testing,2nd Edition, Sage Publishing Co., 2005. In both cases, the (concurrent) predictive power of the test is analyzed using a simple correlation or linear regression. Alignment with classical conceptions of validity Concurrent validity and predictive validity are two types of criterion-related val ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GLITS
Graham's Line Identification Tone System (GLITS) is a test signal for stereo systems devised by BBC TV Sound Supervisor and Fellow of thIPSGraham Haines in the mid 1980s. It comprises a 1 kHz tone at 0 dBu (- 18 dBFS) on both channels, with interruptions which identify the channels. The left channel is interrupted once for 250 ms every 4 seconds. 250 ms later the right channel has two interruptions of 250 ms spaced by 250 ms. This arrangement has an advantage over the EBU stereo ident tone in that each channel is explicitly identified as belonging to a stereo pair. The EBU Technical DocumenMultichannel Audio Line-up Tone(Tech 3304) defines stereo lineup tone as having an interruption in the left channel only, lasting 250 ms every 3 s. Multichannel GLITS There is now an official EBU standard for a multichannel BLITS 5.1 channel ident tone which is also described in the Tech 3304 paper, along with an alternative film-style ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valid (engraving Company)
Valid is a Brazilian engraving company headquartered in Rio de Janeiro that provides security printing services to financial institutions, telecommunication companies, state governments, and public agencies in Brazil, Argentina, and Spain. In total there are 7 factories and 84 "personalization sites". In 2010, sales totaled 465.1 million cards, 15.4 million driver's licenses and identity cards and 12.3 thousand tons of paper. Segment of operation Its Means of Payment segment offers smart cards, such as contact chips, contactless chips, dual interfaces, display cards, and public key infrastructure cards used for payments, identification, personalization and storage, recovery, and safe transmission of data; and magnetic cards, including credit and debit cards, and private labels. This segment also provides security documents, including check books, vouchers, tickets, and lottery scratch off. It serves health plans, public online services, and financial service sectors. The comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valid (number Format)
Unums (''universal numbers'') are a family of formats and arithmetic, similar to floating point, proposed by John L. Gustafson in 2015. They are designed as an alternative to the ubiquitous IEEE 754 floating-point standard. The latest version (known as posits) can be used as a drop-in replacement for programs that do not depend on specific features of IEEE 754. Type I Unum The first version of unums, formally known as Type I unum, was introduced in Gustafson's book ''The End of Error'' as a superset of the IEEE-754 floating-point format. The defining features of the Type I unum format are: * a variable-width storage format for both the significand and exponent, and * a ''u-bit'', which determines whether the unum corresponds to an exact number (''u'' = 0), or an interval between consecutive exact unums (''u'' = 1). In this way, the unums cover the entire extended real number line ˆ’∞,+∞ For computation with the format, Gustafson proposed using i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convergent Validity
Convergent validity, for human cognition, especially within sociology, psychology, and other behavioral sciences, refers to the degree to which two measures that theoretically should be related, are in fact related. Convergent validity, along with discriminant validity, is a subtype of construct validity. Convergent validity can be established if two similar constructs correspond with one another, while discriminant validity applies to two dissimilar constructs that are easily differentiated. Campbell and Fiske (1959) developed the Multitrait-Multimethod Matrix to assess the construct validity of a set of measures in a study. The approach stresses the importance of using both discriminant and convergent validation techniques when assessing new tests. In other words, in order to establish construct validity, you have to demonstrate both convergence and discrimination. Evaluation/application Convergent validity can be estimated using correlation coefficients. A successful evaluat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Criterion Validity
In psychometrics, criterion validity, or criterion-related validity, is the extent to which an operationalization of a construct, such as a test, relates to, or predicts, a theoretical representation of the construct—the criterion. Criterion validity is often divided into concurrent and predictive validity based on the timing of measurement for the "predictor" and outcome. Concurrent validity refers to a comparison between the measure in question and an outcome assessed at the same time. '' Standards for Educational & Psychological Tests'' states, "concurrent validity reflects only the status quo at a particular time." Predictive validity, on the other hand, compares the measure in question with an outcome assessed at a later time. Although concurrent and predictive validity are similar, it is cautioned to keep the terms and findings separated. "Concurrent validity should not be used as a substitute for predictive validity without an appropriate supporting rationale."American Psych ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discriminant Validity
In psychology, discriminant validity tests whether concepts or measurements that are not supposed to be related are actually unrelated. Campbell and Fiske (1959) introduced the concept of discriminant validity within their discussion on evaluating test validity. They stressed the importance of using both discriminant and convergent validation techniques when assessing new tests. A successful evaluation of discriminant validity shows that a test of a concept is not highly correlated with other tests designed to measure theoretically different concepts. In showing that two scales do not correlate, it is necessary to correct for attenuation in the correlation due to measurement error. It is possible to calculate the extent to which the two scales overlap by using the following formula where r_ is correlation between x and y, r_ is the reliability of x, and r_ is the reliability of y: :\cfrac Although there is no standard value for discriminant validity, a result less than 0.70 sugge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predictive Validity
In psychometrics, predictive validity is the extent to which a score on a scale or test predicts scores on some criterion measure. For example, the validity of a cognitive test for job performance is the correlation between test scores and, for example, supervisor performance ratings. Such a cognitive test would have ''predictive validity'' if the observed correlation were statistically significant. Predictive validity shares similarities with concurrent validity in that both are generally measured as correlations between a test and some criterion measure. In a study of concurrent validity the test is administered at the same time as the criterion is collected. This is a common method of developing validity evidence for employment tests: A test is administered to incumbent employees, then a rating of those employees' job performance is, or has already been, obtained independently of the test (often, as noted above, in the form of a supervisor rating). Note the possibility for res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Content Validity
In psychometrics, content validity (also known as logical validity) refers to the extent to which a measure represents all facets of a given construct. For example, a depression scale may lack content validity if it only assesses the affective dimension of depression but fails to take into account the behavioral dimension. An element of subjectivity exists in relation to determining content validity, which requires a degree of agreement about what a particular personality trait such as extraversion represents. A disagreement about a personality trait will prevent the gain of a high content validity. Description Content validity is different from face validity, which refers not to what the test actually measures, but to what it superficially appears to measure. Face validity assesses whether the test "looks valid" to the examinees who take it, the administrative personnel who decide on its use, and other technically untrained observers. Content validity requires the use of recog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Validity
Internal validity is the extent to which a piece of evidence supports a claim about cause and effect, within the context of a particular study. It is one of the most important properties of scientific studies and is an important concept in reasoning about evidence more generally. Internal validity is determined by how well a study can rule out alternative explanations for its findings (usually, sources of systematic error or 'bias'). It contrasts with external validity, the extent to which results can justify conclusions about other contexts (that is, the extent to which results can be generalized). Details Inferences are said to possess internal validity if a causal relationship between two variables is properly demonstrated.Shadish, W., Cook, T., and Campbell, D. (2002). Experimental and Quasi-Experimental Designs for Generilized Causal Inference Boston:Houghton Mifflin. A valid causal inference may be made when three criteria are satisfied: # the "cause" precedes the " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Construct Validity
Construct validity concerns how well a set of indicators represent or reflect a concept that is not directly measurable. ''Construct validation'' is the accumulation of evidence to support the interpretation of what a measure reflects.Polit DF Beck CT (2012). Nursing Research: Generating and Assessing Evidence for Nursing Practice, 9th ed. Philadelphia, USA: Wolters Klower Health, Lippincott Williams & Wilkins Modern validity theory defines construct validity as the overarching concern of validity research, subsuming all other types of validity evidence such as content validity and criterion validity. Construct validity is the appropriateness of inferences made on the basis of observations or measurements (often test scores), specifically whether a test can reasonably be considered to reflect the intended construct. Constructs are abstractions that are deliberately created by researchers in order to conceptualize the latent variable, which is correlated with scores on a given measur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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