Showing papers on "Matching (statistics) published in 1973"

The Representation and Matching of Pictorial Structures

Abstract: The primary problem dealt with in this paper is the following. Given some description of a visual object, find that object in an actual photograph. Part of the solution to this problem is the specification of a descriptive scheme, and a metric on which to base the decision of "goodness" of matching or detection.

Matching to Remove Bias in Observational Studies

Abstract: Several matching methods that match all of one sample from another larger sample on a continuous matching variable are compared with respect to their ability to remove the bias of the matching variable. One method is a simple mean-matching method and three are nearest available pair-matching methods. The methods' abilities to remove bias are also compared with the theoretical maximum given fixed distributions and fixed sample sizes. A summary of advice to an investigator is included.

Matched Sampling for Causal Effects: The Use of Matched Sampling and Regression Adjustment to Remove Bias in Observational Studies

Abstract: The ability of matched sampling and linear regression adjustment to reduce the bias of an estimate of the treatment eff ect in two sample observational studies is investigated for a simple matching method and five simple estimates. Monte Carlo results are given for moderately linear exponential response surfaces and analytic results are presented for quadratic response surfaces. The conclusions are (1) in general both matched sampling and regression adjustment can be expected to reduce bias, (2) in some cases when the variance of the matching variable differs in the two populations both matching and regression adjustment can increase bias, (3) when the variance of the matching variable is the same in the two populations and the distributions of the matching variable are symmetric the usual covariance adjusted estimate based on random samples is almost unbiased, and (4) the combination of regression adjustment in matched samples generally produces the least biased estimate.

Matching bias in the selection task.

Abstract: A previous study (Evans, 1972) found that subjects tend to match rather than alter named values when constructing verifying and falsifying cases of conditional rules. It was suggested that this tendency (‘matching bias’) might account for the responses normally observed in Wason's (1968, 1969) ‘selection task’. This suggestion was tested by giving subjects the selection task with conditional rules in which the presence and absence of negative components was systematically varied, to see whether subjects consistently attempted to verify the rules (Wason's theory) or whether they continued to choose the matching values despite the presence of negatives, which would reverse the logical meaning of such selections. Significant matching tendencies were observed on four independent measures, and the overall pattern, with matching bias cancelled out, gave no evidence for a verification bias, indicating instead that the logically correct values were most frequently chosen.

Randomization models for the matched and unmatched 2 × 2 tables

Abstract: SUMMARY Randomization models for 2 x 2 tables in the matched and unmatched cases are proposed and, in terms of these models, the usual large sample statistical tests are shown to be conservative. The likelihood surface for the unmatched case is discussed. In the matched case, the model takes more explicit account of the effect of the matching criteria used in the trial than do the more familiar probability models. A simple analogue in the case of continuous measurements is indicated.

A note on cross-modality matching.

Abstract: ”Stevens' law”, that the psychophysical law is a power function, is often taken to be confirmed by results of cross-modality matching experiments, for it predicts both the fact that cross-modality matching experiments yield power functions, and the exponents of these power functions. Both these predictions, however, follow from a more general form of the psychophysical law, of which Fechner's law is a special case. In view of this, an interpretation of cross-modality matching based on stimulus discriminability rather than sensation magnitude is proposed.

Processing capacity in a letter-matching task.

Abstract: 1

Adaptive correction of program statements

Abstract: A method of analyzing statements in a programming language which can tolerate a considerable inaccuracy in their specification is proposed. This method involves principles at present mainly confined to studies in the area of artificial intelligence such as feature extraction, approximate tree matching, and strategy improvement by feedback from the matching process. A pilot program incorporating the principles is described and preliminary operating results are presented. A final section surveys further principles which are currently being investigated.

Measuring instructional results, or, Got a match?

Abstract: What it's all about distinctions decoding the objective matching the performances matching the conditions peripherallia - a pride of items got a match?.

On the Mismatch Between Data and Models of Hydrologic and Water Resource Systems

Abstract: Many difficulties exist in the matching of models with data. This paper identifies elements of this problem and discusses considerations involved in model evaluation. The well known multivariate linear regression model is used to illustrate the distinctions between accuracy and precision and between estimation and prediction (because the model is commonly misused.) No amount of additional data will improve the accuracy of a poor model. A high R2, while indicative of a good matching between the observed data and model estimates, is a poor criterion for judging adequacy of the model to make good predictions of future events. Model evaluation also includes the problem of introducing secondary data and proxy variables into a model. Secondary data frequently enter, for example, the mass, energy and water budget equations because of difficulties in measuring the primary variables. Proxy variables arise because of a desire to collapse a vector of incomparable values, say, of water quality into a single number. Review of the above issues indicates that model evaluation is a multi-criterion problem, often imbedded in a larger framework where models are intended to meet multiple objectives. The mismatch of models and data has increasing legal and social consequences.

The way we do things here

Abstract: One of the most depressing features of the business and educational world is the continuing division between the educationist, the instructor and the business executive. This barrier has remained despite the efforts of the business schools and the industrial training boards. The major difficulty is matching the criteria of profitability with the aspirations of the educationist.

Matching of High Output Diesel Engines with Associated Turbomachinery: First Paper: A General Approach to the Computer Solution of Single- and Two-Stage Turbocharged Diesel Engine Matching

Abstract: The first paper describes the general approach adopted in the solution of steady-state matching of single-stage turbocharged engines with fixed and variable geometry turbines and two-stage turbocharged engines developed from general principles first reported in (1). Individual components are represented either by systems of equations or by multi-dimensional numerical arrays embodied in separate subroutines which are called from a main-linking programme containing the overall matching equations. Appropriate iterative procedures from initially assumed values of boost and turbocharger speed (for single- or two-stage arrangements) are briefly described.The programmes have been run both in batch processing and interactive mode, and in the latter form have been found particularly valuable as teaching aids.

A Statistical Analysis of the O E O Experiment in Educational Performance Contracting

Abstract: Private educational firms claimed to be able to substantially increase the reading and mathematics achievement test scores of disadvantaged students. The OEO Performance Contracting Experiment tested this claim. Although analysis of experimental effects is complicated by imperfect matching of experimental and control students and by measurement error in pretest scores, there are statistical techniques for dealing with these problems. Our results indicate that the private companies which participated in the experiment did not have the capability of bringing about any great improvement in the educational status of disadvantaged students.

A Linear Description of the Second Species Solutions

Abstract: From Breakwell-Perko’s Matching Theory, we deduce I/O Equations relating the ‘histories’ of a second species solution before and after its passage near the Moon. We give some applications of these equations.

Factor analyses of work-relevant need statements in two populations

Abstract: A questionnaire of 5 items for each of 21 job-relevant medical categories was constructed. With one set of instructions, these items were used to assess need strengths among college students anticipating future employment; with different instructions, the same items were used to assess need satisfaotions of employd college graduates. Principal axis factor analysis yielded 11 and 12 factors, respectively, in the two sets of data. Factor matching (using the BC TRY computer system) showed six common dimensions, one of which was clearly a composite of two independent clusters of items. Seven 4-item scales were selected as measures of (la) need to be creative, (lb) need for work activity, (2) need to have authority, (3) need for maintenance of moral values, (4) need for advancement, (6) need for mutual respect, and (6) need for good working conditions. The scales proved sufficiently reliable and independent for use in longitudinal research.

Matching needs and resources;: Reforming the Federal Budget

Abstract: This book continues AEIA¢Â€Â™s series of annual reviews of the federal budget. It includes, in addition to a review of the programmatic content of the new budget, a discussion of the fiscal policy that the budget proposes.

Moments of a Card Matching Distribution

Abstract: (1973). Moments of a Card Matching Distribution. The American Statistician: Vol. 27, No. 4, pp. 166-166.

Effects of Δ9-tetrahydrocannabinol on delayed matching-to-sample choice speeds in chimpanzees

Abstract: The effects of Δ9-THC on choice response speeds in chimpanzee short-term recognition memory were assessed in a delayed matching-to-sample task. Choice speeds were faster on correct than on incorrect trials and were inversely related to delay length. Although Δ9-THC lowered matching accuracy, it did not affect any aspect of choice speed. These results were interpreted as indicating that the disruption of short-term recognition memory produced by Δ9-THC reflects changes in acquisition-storage processes rather than in memory retrieval processes.

Acquisition of zero-delay matching in pigeons

Abstract: The present report describes a procedure for generating efficient zero-delay matching in pigeons. Introducing a third CO to disrupt the position preference characteristic of preacquisiton performance under two-choice matching conditions was followed almost immediately by a steady increase in correct responding to near errorless levels.