RELIABILITY, VALIDITY, AND TRUSTWORTHINESS

Reliability, Validity, and Trustworthiness

Reliability, Validity, and Trustworthiness

Introduction

An evidence based practice in nursing researcher attempts to fragment and delimit phenomena into measurable or common categories that can be applied to all of the subjects or wider and similar situations (Winter, 2000). In his/her attempts, the researcher's methods involve the "use of standardised measures so that the varying perspectives and experiences of people can be fit into a limited number of predetermined response categories to which number are assigned" (Patton, 2001, p.14). For example, an evidence based practice in nursing researcher may prepare a list of behaviour to be checked or rated by an observer using a predetermined schedule or numbers (scales) as an instrument in his/her method of research. Thus, an evidence based practice in nursing researcher needs to construct an instrument to be administered in standardised manner according to predetermined procedures. But the question is if the measuring instrument measures what it is supposed to measure. In the broadest sense, devising a test (Crocker & Algina, 1986) or the validity of an instrument is on focus. The significance of this test is to ensure replicability or repeatability of the result.

Reliability

Although the term 'Reliability' is a concept used for testing or evaluating evidence based practice in nursing research, the idea is most often used in all kinds of research. If we see the idea of testing as a way of information elicitation then the most important test of any qualitative study is its quality. A good qualitative study can help us “understand a situation that would otherwise be enigmatic or confusing” (Eisner, 1991, p. 58). This relates to the concept of a good quality research when reliability is a concept to evaluate quality in evidence based practice in nursing study with a “purpose of explaining” while quality concept in qualitative study has the purpose of “generating understanding” (Stenbacka, 2001, p. 551). The difference in purposes of evaluating the quality of studies in evidence based practice in nursing and evidence based practice in nursing research is one of the reasons that the concept of reliability is irrelevant in qualitative research. According to Stenbacka, (2001) “the concept of reliability is even misleading in qualitative research. If a qualitative study is discussed with reliability as a criterion, the consequence is rather that the study is no good” (p. 552).

Validity

The concept of validity is described by a wide range of terms in qualitative studies. This concept is not a single, fixed or universal concept, but “rather a contingent construct, inescapably grounded in the processes and intentions of particular research methodologies and projects” (Winter, 2000, p.1). Although some qualitative researchers have argued that the term validity is not applicable to qualitative research, but at the same time, they have realised the need for some kind of qualifying check or measure for their research. For example, Creswell & Miller (2000) suggest that the validity is affected by the researcher's perception of validity in the study and his/her choice of paradigm ...