Orthogonal Regression, the Cleary Criterion, and Lord's Paradox: Asking the Right Questions. Research Report. ETS RR-20-14

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Bibliographic Details
Title: Orthogonal Regression, the Cleary Criterion, and Lord's Paradox: Asking the Right Questions. Research Report. ETS RR-20-14
Language: English
Authors: Kane, Michael T., Mroch, Andrew A.
Source: ETS Research Report Series. Dec 2020.
Availability: Educational Testing Service. Rosedale Road, MS19-R Princeton, NJ 08541. Tel: 609-921-9000; Fax: 609-734-5410; e-mail: RDweb@ets.org; Web site: https://www.ets.org/research/policy_research_reports/ets
Peer Reviewed: Y
Page Count: 24
Publication Date: 2020
Document Type: Journal Articles
Reports - Evaluative
Descriptors: Regression (Statistics), Least Squares Statistics, Test Bias, Error of Measurement, Statistical Analysis, Prediction, Factor Analysis, Models
ISSN: 2330-8516
Abstract: Ordinary least squares (OLS) regression and orthogonal regression (OR) address different questions and make different assumptions about errors. The OLS regression of Y on X yields predictions of a dependent variable (Y) contingent on an independent variable (X) and minimizes the sum of squared errors of prediction. It assumes that the independent variable (X) is an observed score that is known without error, and all of the error is assigned to the dependent variable (Y). OLS is not designed to estimate underlying functional relationships, and if both variables contain error, OLS regression tends to yield biased estimates of such functional (or true-score) relationships. OR models, including the errors-in-variables (EIV) and geometric-mean (GM) models, assume that both variables contain error and seek to identify the line that minimizes squared deviations of the data points from the line in both the X and Y directions. OLS and OR address different questions and serve different purposes. If one wants to predict one variable from another variable, OLS regression is an optimal approach and OR is less efficient; in examining the functional relationship between two variables, OR provides a more plausible model. The OR models are hard to apply in many contexts because they depend on strong assumptions about sources of error. As examples of cases where OR can shed light, we examine its use in analyzing test bias as distinct from predictive bias and in making sense of Lord's paradox.
Abstractor: As Provided
Entry Date: 2021
Accession Number: EJ1284925
Database: ERIC
Description
Abstract:Ordinary least squares (OLS) regression and orthogonal regression (OR) address different questions and make different assumptions about errors. The OLS regression of Y on X yields predictions of a dependent variable (Y) contingent on an independent variable (X) and minimizes the sum of squared errors of prediction. It assumes that the independent variable (X) is an observed score that is known without error, and all of the error is assigned to the dependent variable (Y). OLS is not designed to estimate underlying functional relationships, and if both variables contain error, OLS regression tends to yield biased estimates of such functional (or true-score) relationships. OR models, including the errors-in-variables (EIV) and geometric-mean (GM) models, assume that both variables contain error and seek to identify the line that minimizes squared deviations of the data points from the line in both the X and Y directions. OLS and OR address different questions and serve different purposes. If one wants to predict one variable from another variable, OLS regression is an optimal approach and OR is less efficient; in examining the functional relationship between two variables, OR provides a more plausible model. The OR models are hard to apply in many contexts because they depend on strong assumptions about sources of error. As examples of cases where OR can shed light, we examine its use in analyzing test bias as distinct from predictive bias and in making sense of Lord's paradox.
ISSN:2330-8516