The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Graeme D. Ruxton - One of the best experts on this subject based on the ideXlab platform.
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the unequal variance t test is an underused alternative to student s t test and the mann whitney u test
Behavioral Ecology, 2006Co-Authors: Graeme D. RuxtonAbstract:Often in the study of behavioral ecology, and more widely in science, we require to statistically test whether the central tendencies (mean or median) of 2 groups are different from each other on the basis of samples of the 2 groups. In surveying recent issues of Behavioral Ecology (Volume 16, issues 1–5), I found that, of the 130 papers, 33 (25%) used at least one statistical comparison of this sort. Three different tests were used to make this comparison: Student’s T-Test (67 occasions; 26 papers), Mann–Whitney U test (43 occasions; 21 papers), and the T-Test for unequal variances (9 occasions; 4 papers). My aim in this forum article is to argue for the greater use of the last of these tests. The numbers just related suggest that this test is not commonly used. In my survey, I was able to identify tests described simply as ‘‘T-Tests’’ with confidence as either a Student’s T-Test or an unequal variance T-Test because the calculation of degrees of freedom from the 2 sample sizes is different for the 2 tests (see below). Hence, the neglect of the unequal variance T-Test illustrated above is a real phenomenon and can be explained in several (nonexclusive ways) ways: 1. Authors are unaware that Student’s T-Test is unreliable
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The unequal variance T-Test is an underused alternative to Student's T-Test and the Mann–Whitney U test
Behavioral Ecology, 2006Co-Authors: Graeme D. RuxtonAbstract:Often in the study of behavioral ecology, and more widely in science, we require to statistically test whether the central tendencies (mean or median) of 2 groups are different from each other on the basis of samples of the 2 groups. In surveying recent issues of Behavioral Ecology (Volume 16, issues 1–5), I found that, of the 130 papers, 33 (25%) used at least one statistical comparison of this sort. Three different tests were used to make this comparison: Student’s T-Test (67 occasions; 26 papers), Mann–Whitney U test (43 occasions; 21 papers), and the T-Test for unequal variances (9 occasions; 4 papers). My aim in this forum article is to argue for the greater use of the last of these tests. The numbers just related suggest that this test is not commonly used. In my survey, I was able to identify tests described simply as ‘‘T-Tests’’ with confidence as either a Student’s T-Test or an unequal variance T-Test because the calculation of degrees of freedom from the 2 sample sizes is different for the 2 tests (see below). Hence, the neglect of the unequal variance T-Test illustrated above is a real phenomenon and can be explained in several (nonexclusive ways) ways: 1. Authors are unaware that Student’s T-Test is unreliable
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The unequal variance T-Test is an underused alternative to Student's T-Test and the Mann-Whitney U test
Behavioral Ecology, 2006Co-Authors: Graeme D. RuxtonAbstract:Salmon barged down the columbia had significantly higher rates of straying and mortality in adults in the Columbia River
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The unequal variance T-Test is an underused alternative to Student's T-Test and the Mann–Whitney U test
Behavioral Ecology, 2006Co-Authors: Graeme D. RuxtonAbstract:Salmon barged down the columbia had significantly higher rates of straying and mortality in adults in the Columbia River
Navneet Garg - One of the best experts on this subject based on the ideXlab platform.
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slow rolling response tests on the test pavements at the national airport pavement test facility naptf
27th International Air Transportation Conference, 2001Co-Authors: Gordon F Hayhoe, Robert Cornwell, Navneet GargAbstract:Airport pavement thickness design procedures predict a significant amount of interaction between the loads from multiple wheel and closely spaced multiple truck landing gear configurations. But the true degree of interaction is not known, and measurements from full scale tests are required to determine how closely wheels and trucks can be spaced without significant load interaction. As a supplement to traffic tests run to failure at a later date, pavement response tests were performed to study the wheel load interaction effects. Pavement responses were measured at various depths in each of the 9 pavement test items at the National Airport Pavement Test Facility (NAPTF) for different combinations of wheel and truck configurations, and load levels. This paper describes the response test objectives and test procedures. Some typical pavement responses are presented. Data from the response tests is being analyzed at the FAA Center of Excellence for Airport Technology at the University of Illinois. The raw data is also available from the FAA for independent analyses.
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slow rolling response tests on the test pavements at the national airport pavement test facility naptf in advancing airfield pavements
Advancing Airfield Pavements. Proceedings of the 2001 Airfield Pavement Specialty ConferenceAmerican Society of Civil Engineers, 2001Co-Authors: Gordon F Hayhoe, Robert Cornwell, Navneet GargAbstract:The paper reports on pavement response tests that were performed to study the wheel load interaction effects. The objectives of the tests were to: measure pavement response with precise control of magnitude/position of load; measure interaction of pavement response at different wheel and gear spacings; compare response with static and moving loads; compare response with static and heavy weight deflectometer loads; compare measured responses with computed responses. Described are the response test objectives and test procedures.
Thomas R Coyle - One of the best experts on this subject based on the ideXlab platform.
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Test–retest changes on scholastic aptitude tests are not related to g
Intelligence, 2020Co-Authors: Thomas R CoyleAbstract:Abstract This research examined the relation between test–retest changes on scholastic aptitude tests and g-loaded cognitive measures (viz., college grade-point average, Wonderlic Personnel Test, and word recall). University students who had twice taken a scholastic aptitude test (viz., Scholastic Assessment Test or American College Testing Program Assessment) during high school were recruited. The aptitude test raw scores and change scores were correlated with the g-loaded cognitive measures in two studies. The aptitude test change scores (which were mostly gains) were not significantly related to the cognitive measures, whereas the aptitude test raw scores were significantly related to those measures. Principal components analysis indicated that the aptitude test change scores had the lowest loading on the g factor, whereas the aptitude test raw scores and the cognitive measures had relatively high loadings on the g factor. These findings support the position that test–retest changes on scholastic aptitude tests do not represent changes in g. Further research is needed to determine the non-g variance components that contributed to the observed test–retest changes.
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test retest changes on scholastic aptitude tests are not related to g
Intelligence, 2006Co-Authors: Thomas R CoyleAbstract:Abstract This research examined the relation between test–retest changes on scholastic aptitude tests and g-loaded cognitive measures (viz., college grade-point average, Wonderlic Personnel Test, and word recall). University students who had twice taken a scholastic aptitude test (viz., Scholastic Assessment Test or American College Testing Program Assessment) during high school were recruited. The aptitude test raw scores and change scores were correlated with the g-loaded cognitive measures in two studies. The aptitude test change scores (which were mostly gains) were not significantly related to the cognitive measures, whereas the aptitude test raw scores were significantly related to those measures. Principal components analysis indicated that the aptitude test change scores had the lowest loading on the g factor, whereas the aptitude test raw scores and the cognitive measures had relatively high loadings on the g factor. These findings support the position that test–retest changes on scholastic aptitude tests do not represent changes in g. Further research is needed to determine the non-g variance components that contributed to the observed test–retest changes.
Gordon F Hayhoe - One of the best experts on this subject based on the ideXlab platform.
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slow rolling response tests on the test pavements at the national airport pavement test facility naptf
27th International Air Transportation Conference, 2001Co-Authors: Gordon F Hayhoe, Robert Cornwell, Navneet GargAbstract:Airport pavement thickness design procedures predict a significant amount of interaction between the loads from multiple wheel and closely spaced multiple truck landing gear configurations. But the true degree of interaction is not known, and measurements from full scale tests are required to determine how closely wheels and trucks can be spaced without significant load interaction. As a supplement to traffic tests run to failure at a later date, pavement response tests were performed to study the wheel load interaction effects. Pavement responses were measured at various depths in each of the 9 pavement test items at the National Airport Pavement Test Facility (NAPTF) for different combinations of wheel and truck configurations, and load levels. This paper describes the response test objectives and test procedures. Some typical pavement responses are presented. Data from the response tests is being analyzed at the FAA Center of Excellence for Airport Technology at the University of Illinois. The raw data is also available from the FAA for independent analyses.
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slow rolling response tests on the test pavements at the national airport pavement test facility naptf in advancing airfield pavements
Advancing Airfield Pavements. Proceedings of the 2001 Airfield Pavement Specialty ConferenceAmerican Society of Civil Engineers, 2001Co-Authors: Gordon F Hayhoe, Robert Cornwell, Navneet GargAbstract:The paper reports on pavement response tests that were performed to study the wheel load interaction effects. The objectives of the tests were to: measure pavement response with precise control of magnitude/position of load; measure interaction of pavement response at different wheel and gear spacings; compare response with static and moving loads; compare response with static and heavy weight deflectometer loads; compare measured responses with computed responses. Described are the response test objectives and test procedures.
Robert Cornwell - One of the best experts on this subject based on the ideXlab platform.
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slow rolling response tests on the test pavements at the national airport pavement test facility naptf
27th International Air Transportation Conference, 2001Co-Authors: Gordon F Hayhoe, Robert Cornwell, Navneet GargAbstract:Airport pavement thickness design procedures predict a significant amount of interaction between the loads from multiple wheel and closely spaced multiple truck landing gear configurations. But the true degree of interaction is not known, and measurements from full scale tests are required to determine how closely wheels and trucks can be spaced without significant load interaction. As a supplement to traffic tests run to failure at a later date, pavement response tests were performed to study the wheel load interaction effects. Pavement responses were measured at various depths in each of the 9 pavement test items at the National Airport Pavement Test Facility (NAPTF) for different combinations of wheel and truck configurations, and load levels. This paper describes the response test objectives and test procedures. Some typical pavement responses are presented. Data from the response tests is being analyzed at the FAA Center of Excellence for Airport Technology at the University of Illinois. The raw data is also available from the FAA for independent analyses.
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slow rolling response tests on the test pavements at the national airport pavement test facility naptf in advancing airfield pavements
Advancing Airfield Pavements. Proceedings of the 2001 Airfield Pavement Specialty ConferenceAmerican Society of Civil Engineers, 2001Co-Authors: Gordon F Hayhoe, Robert Cornwell, Navneet GargAbstract:The paper reports on pavement response tests that were performed to study the wheel load interaction effects. The objectives of the tests were to: measure pavement response with precise control of magnitude/position of load; measure interaction of pavement response at different wheel and gear spacings; compare response with static and moving loads; compare response with static and heavy weight deflectometer loads; compare measured responses with computed responses. Described are the response test objectives and test procedures.
