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DOCUMENT RESUME ED 090 962 64 IR 000 573 AUTHOR Lord, Harold G. TITLE Ex Post Facto Studies as a Research Method. Special Report No. 7320. INSTITUTION Syracuse City School District, N.Y. SPONS AGENCY Bureau of Education for the Handicapped (DREW /OE), Washington, D.C. Media Services and Captioned Films Branch. PUB DATE Jul 73 CONTRACT OEC-9-423617-4357(616) NOTE 16p.; Supporting document for the Computer-Based Project for the Evaluation of Media for the Handicapped; For related documents see IR 000 572, 574, and 575 EDRS PRICE MF-$0.75 HC-$1.50 PLUS POSTAGE DESCRIPTORS *Comparative Analysis; Comparative Statistics; Control Groups; *Correlation; Research; *Research Design; *Research Methodology; Statistical Analysis IDENTIFIERS BEH; Bureau of Education for the Handicapped; Computer Based Project Evaluation Media Handicapp; Quasi Experimental Design ABSTRACT This paper presents the causal comparative method, or ex post facto research design, as an alternative to classical experimental methods for establishing causal relationships between events and circumstances. h literature survey, conducted in an effort to define and describe the method is discussed. Following this is a presentation of the relationship between the correlation method and the causal comparative method. Both the strengths and weaknesses of the ex post facto research designs are detailed. (WDR) SPECIAL REPORT #7320 Harold G. Lord July 1973 EXPOST FACTO STUDIES AS A RESEARCH METHOD Harold G. Lord ABSTRACT Employing the experimental method in research is sometimes impractical or prohibitively costly in time, money, and effort; in other instances, it is unethical or immoral. The causal comparative method or ex post facto research design, outlined in this paper, is an alternative method for establishing causal relation-. ships between events and circumstances. The literature was surveyed in an effort to define and describe the method. The relationship between the correlation method and the causal comparative method is also dis- cussed. Both the strengths and the weaknesses of ex post facto research designs are detailed. DrP4R YENT OF 1.4E-4,. E0UCATION6 lat..FARf NATIONAL OF EDUCAtiON c,,q DPC,,V,F1t "K.; pEEN ExAe riNe It; F cINV ,r _ - E REPORT No. 7320 SPECIAL COMPUTER-BASED PROJECT for the EVALUATION of MEDIA for the HANDICAPPED e: "EXPOST FACTO STUDIES AS A RESEARCH METHOD" Tit I _ BY:Harold G. Lord BACKGROUND The Computer Based Project for the Evaluation of Media for the Handicapped, based on contract #0EC-9-423617-4357 (616) between the Syracuse (N.Y.) City School District and the Media Services and Captioned Films Branch, Bureau of Education for the Handicapped (United States Office of Education) for the five year period July 1, 1969 through June 30, 1974. The major goal is to improve the instruction of handicapped children through the development and use of an evaluation system to measure the instructional effectiveness of films and other materials with educable mentally handicapped (EMH) children, in-service training and media support for special teachers, and studies related to the evaluation process anti the populations used. The Project has concentrated on the 600 films and 200 filmstrips from the Media Services and Captioned Films (BEH - USOE) depository; however, specific packages from Project LIFE, various elementary math curricula, and selected programs from Children's TV Workshop have also been evaluated. The evaluation model used requires that 1) objectives of materials be specified and written; 2) instruments be constructed to test and measure effectiveness; and; 3) children be the major sources of evaluation information. A number of instruments and methodologies are employed in the gathering of cognitive and affective data from 000 EMH children and 80 special teachers to make the effectiveness decisions. Over half of the EMH population can neither read or write; therefore, a unique Student Response System (SRS) is employed, consisting of a twenty station G.E. - 1000 SRS which can be operated in a group or individual recording mode and is connected to a remote computer system. The computer capabilities consist of remote telephone connections to the Rome (N.Y.) Air Development Command, the Honeywell time-shared network, and the Schenectady (N.Y.) G E Research and Development Center; and batch mode capabilities of the Syracuse City Schools, Syracuse University, and various commercial sources. In-service and media support activities provide on-the-job training for teachers, teacher aides, equipment, and materials to the special teachers in the city schools. The research activities have centered around investigations and special problems related to the development of the evaluation model. The four major areas considered are: 1) testing effects, 2) captioning effects, 3) special student characteristics; and, 4) evaluation procedures validation. Documentation of the major activities appear in the five annual reports and the 600 evaluations prepared on materials used. Staff members were encouraged to prepare special reports and the attached paper is one of these. The opinions expressed in this publication do not necessarily reflect the position or policy of the Computer Based Project, the United States Office of Education, or the Syracuse City School District, and no official endorsement by any of the agencies should be inferred. Occesional Paper ;,/7320 Harold G. Lord July 1973 Experimental, cducational research has 'been derived from the laboratory method often used in the natural sciences. According to Galfo and Miller (1970) in its most elementary form, the experimental method of science .is based upon two assumptions regarding variables which may be identified with the phenomenon under investigation: 1. If two situations are equal in every respect except for a factor present in one of the sit- uations, any difference which appears between the two situations can be attributed to the factor. This statement is referred to as the law of the single variable. 2. If two situations are not equal but it can be demonstrated that none of the variables are significant in producing the phenomenon under investigation; or if significant variables are made equal, any difference occurring between the two situations after the introduction of a new variable to one of the systems can be attributed to the new variable. This statement is referred to as the law of the only signifi- cant variable [p. 17]. The purpose of establishing experimental-control conditions is to create a situation in which the effect of a single variable can be studied, In the behavioral sciences many problems cannot be solved by the experimental method. Because of the complex- ity and nature of social phenomena, one cannot always select
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