Exploratory Study on Circular Economy Approaches A Comparative Analysis of Theory and Practice

40 3 Research Method

lies in further advancing theory on circular economy and providing a conceptual

understanding of it (Bansal and Corley 2012; Eisenhardt 1989). To further research

on the circular economy it was necessary to ensure that the case studies selected

provided rich, detailed and evocative data. This is why interviews have been con-

ducted with open-ended questions and documents have been gathered to explore

the concept of circular economy (Edmondson and McManus 2007).

Secondly, the objective of an exploratory study is to develop insights into a new

phenomenon and explore it in depth in order to formulate propositions (Edmond-

son and McManus 2007; Kohlbacher 2005; Eisenhardt 1989). Instead of testing

hypotheses, as is typically done in quantitative research, qualitative research aims

to formulate propositions (Mayring 2010).

A benefit deriving from the decision to use a qualitative research methodology

is the large amount of flexibility within the research process (Kohlbacher 2005).

It allows to iteratively alter the research design throughout the process of data

collection and analysis. The findings in each case analysis influenced which case

was selected next. Furthermore, a slight adaption of research questions has been

made to gain meaningful and substantial results.

3.1.2 Quality Criteria in Qualitative Research

Since case study research in general is often criticized as subjective and interpretive

(Flyvbjerg 2006) quality criteria have been identified aiming to ensure a valid and

reliable approach. This chapter will name these criteria, explain them and then

outline how these were adhered to.

The first quality criterion is validity. Gibbert et al. (2008) identify three types

of validity internal, construct and external. While they all are interdependent, a

hierarchical order can be distinguished. For example, external validity can only

be achieved when construct and internal validity are ensured (Gibbert et al. 2008).

Internal validity “refers to the causal relationship between variables and result”

(Gibbert et al. 2008, p. 1466). It has to be assured that x causes y without a third

factor z which might not be observed. This criterion requires thorough work from

the researcher in order to build the conclusion on a powerful, logical and compre-

hensible chain of arguments. Additionally, to further enhance the internal validity,

it is important that researchers compare their results with other established patterns

from previous studies, even patterns from different contexts (Yin 2014; Gibbert et

al. 2008; Eisenhardt 1989). To ensure internal validity, findings from individual

cases have been iteratively compared to each other in order to provide universal

explanations fitting all cases. Moreover, an extensive review of the literature has