Quantification of Self-Report Data From Two-Dimensional Body Diagrams

Abstract

INTRODUCTIONA balance scale and a compensating polar planimeterwere assessed as to their precision in quantifying facsimiles of self-report data obtained on body diagrams. The need to develop ways to quantify body diagram self-report data came about as a result of on-going research on the menopausal hot flash, wherein subjects were asked to shade in areas on front and back body diagrams where they perceived the hot flash to originate and spread. To assess whether body diagrams were a reliable and valid research instrument for evaluating self-report phenomenon, two methods of quantification were tested: (1) weight measurements, using a balance scale, and (2) surface area measurements, using a planimeter. Methods of procedure for both are described in detail in this report.In the weight method, selected body parts were cut out from body diagrams and weighed on a balance scale. In the tracer method, surface area facsimiles of the same body parts were traced using a compensating polar planimeter. Accuracy of instruments was estimated as was precision and validity of the methods. Relative error for both weight and planimetry increased as size of body part to be traced or weighed decreased. Range of error was from 0.05 to 4.17% for weight (large to small part respectively); range of error for planimetry was 0.76 at UNIV OF PITTSBURGH on June 18, 2015 wjn.sagepub.com Downloaded from 708 to 38.9% for large to small body part traced. High,error in measuring small body parts was related to the sensitivity of both instruments. Suggested applications for weight and planimetry as methods to quantify other clinical phenomena are discussed as is terminology used to evaluate accuracy and precision when using bioinstrumentation. PURPOSEThe purpose of this paper is to describe how two instruments used in biological and physical sciences, (1) a balance scale and (2) a compensating polar planimeter, were tested for reliability and validity in quantifying subjective self-report data obtained through the use of body diagrams. The need to find ways to quantify self-report data using body diagrams came about as part of a study on the menopausal hot flash.' Subjects were given front and back body diagrams printed on a white piece of paper and were asked to shade in origin and spread of their hot flash(es). This paper reports on the assessment of reliability and validity of the two procedures, weight and planimetry, as methods to quantify self-report data using shaded in body diagrams. The methods of procedure followed are described in detail in the technical comments section so that the reader can either replicate the procedures or develop other ways in which the body diagram method might be used to quantify subjective or clinical phenomena. Self-Report DataThe acquisition and quantification of self-report data in nursing research has been done chiefly through the use of tools and methods developed by social scientists, such as interviews (structured and unstructured), questionnaires, scales, and the like. Self-report instruments and tec...