A critical review of the Delphi technique as a research methodology for nursing
Introduction
The Delphi technique, originally developed by the RAND Corporation, is a structured process which utilises a series of questionnaires or rounds to gather and to provide information. The process continues until ‘group’ consensus is reached (Beretta, 1996, Green et al., 1999). It is growing in popularity especially for nurse researchers and for health research in general (McKenna, 1994). This growth is centred upon the fact that, like a questionnaire, it allows the inclusion of a large number of individuals across diverse geographic locations and expertise. Unlike questionnaires however, the ‘Delphi’ aims to gather consensus of opinion, judgement or choice. One of its key advantages is that unlike a face to face meeting of experts, the postal ‘Delphi’ is useful when it is anticipated that a specific expert might (advertently or inadvertently) dominate the consensus process (Jaiarth and Weinstein, 1994; Critcher and Gladstone, 1998). While there is a great volume of literature surrounding the Delphi technique, there is a lack of critical examination of the process. The paper aims to fill this gap and take a critical look at the ‘Delphi’ through an analysis of its key aspects.
Section snippets
The Delphi process
In its original form, the Delphi process begins with an initial questionnaire (round one), which acts as an idea-generation strategy to uncover the issues pertaining to the topic under study. To do this, the respondents, referred to as panellists, should put forward as many relevant issues as possible in round one. Once analysed these responses act as a springboard for the rest of the Delphi process. Feedback from round one is provided in the form of a second questionnaire and opinion is asked
Defining the Delphi
The Delphi has been defined as an iterative process designed to combine expert opinion into group consensus (Lynn et al., 1998). According to Dalkey and Helmer (1963) it is a method “used to obtain the most reliable consensus of opinion of a group of experts by a series of intensive questionnaires interspersed with controlled feedback” (cited in McKenna, 1994). There are many differing forms of Delphi now in existence such as the ‘modified Delphi’ (McKenna, 1994), the ‘policy Delphi’ (Crisp et
Characteristics of the Delphi
There are a number of features that characterise the basic Delphi procedure that are of particular importance in terms of a critical review.
Reliability and validity
The Delphi has been criticised heavily as having no evidence of reliability. In other words if the same information were given to two or more panels there is no guarantee that the same results be obtained (Williams and Webb, 1978, Walker and Selfe, 1996). Other Delphi users have however found that the technique was accurate. For example, Ono and Wedemeyer (1994) report on the results of a study designed to replicate a Delphi study 16 years earlier. They state that results show that the findings
Consensus
It should be noted that the existence of consensus from a Delphi process does not mean that the correct answer has been found. This method is not a replacement for rigorous scientific reviews of published reports or for original research. There is a danger that the ‘Delphi’ can lead the observer to place greater reliance on their results than might otherwise be warranted. In addition, the Delphi has been criticised as a method which forces consensus and is weakened by not allowing participants
Ethical considerations
The Delphi is open to the same ethical considerations as any postal survey in that the researcher cannot be certain that the nominated individual is the person who completed the questionnaire or whether it has been the focus of discussion with other individuals. It is also impossible to ascertain whether individuals respond with honesty or respond according to their perception of what the researcher expected. This brings us once again to anonymity. Beretta (1996) points to studies by Hitch and
Applications of the Delphi in nursing research
The Delphi technique has been utilised by many nurse researchers in a wide variety of studies. McKenna (1994) used a modified Delphi using ward managers to select a nursing model appropriate for the care of psychiatric patients in Northern Ireland. Beech (1997) used a Delphi of three rounds to gain consensus on how multi-disciplinary clinical staff view the development of community mental health centres over the course of 2 years in North Staffordshire. Gibson (1998) also used a third round
Conclusion
From existing literature, especially recent literature, it is apparent that the Delphi technique is becoming increasingly popular in nursing research. As stated previously, however, modification to the classic version of the Delphi is widespread. This may cause difficulties methodologically (McKenna, 1994). The ‘Delphi’ however does have advantages over common survey methods. Consequently, used correctly and rigorously the Delphi can contribute significantly to broadening knowledge within the
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