Constant Comparison

The constant comparative method is the core defining feature of analysis in the Grounded Theory method introduced by Glaser and Strauss (Glaser and Strauss, 1967; Strauss, 1987; Glaser, 1992) but it has been previously noted that the application of the method has, at times, been unclear. For this reason Boeije (2002) describes a purposeful approach to the use of constant comparison which was developed in a study similarly considering within- couple processes. This same five-step approach to the use of the constant comparative

62 method was adopted in the current study, throughout the open and axial coding phases, in order to increase the systematic nature and traceability of the analysis, and it is described in detail below.

2.7.4.1 Comparison within a single interview

At the beginning, comparison was conducted within single interviews. Each interview was studied in detail, and open codes were generated to make reference to what had been said by the participant. By comparing different parts of the interview, an appreciation was made of the level of consistency of the interview as a whole. As early codes were then grouped into categories, each reference to the same category was compared to see whether new information was being gleaned or the same information was being repeated. Further within- interview comparisons of emergent codes then allowed the researcher to engage in focused coding, determine how codes linked with the same category differed, and what they had in common, and also to consider the context within which they were mentioned. The overall aim here was to formulate the core message of the interview and develop an understanding of the interview and any associated difficulties, highlights, or inconsistencies. The results of this stage were interview summaries, provisional codes, and memos describing the analysis process (see Appendices H & I).

2.7.4.2 Comparison between interviews within the same group

The next step involved the comparison of interviews within the same group, which meant the comparison of the interviews of participants sharing the same experience. The primary example in the current study is women attempting to quit smoking because of their pregnancy. It became important at this stage to define the characteristics of each category in order to determine which interviews could be grouped together on the basis of similarities.

63 This next step provides an opportunity for triangulation , which is viewed as an important part of qualitative analysis (Boeije, 2002; Johnson and Waterfield, 2004). Interviews from different groups were compared with regard to their experience of a particular issue or phenomenon. Initially this involved the comparison of pregnant women with their partners. The partners’ interviews were carried out in the same way as the women’s interviews, and were used to gain additional information about the nature of the couples’ relationships, and also to gain a better understanding of the women’s’ smoking cessation related beliefs and behaviours. Partners were thus asked about the women’s cessation attempts (as well as their own attempts) and their answers were then compared with the answers given by the women themselves. This provided the researcher with a deeper level of insight and a valuable understanding of the differences in the experiences of expectant male and female smokers.

2.7.4.4 Comparison in pairs at the level of the couple

This step was particularly helpful for developing an understanding of the interpersonal dynamics of the couples. As per Boeije’s guidelines, the interactions of each couple were recreated on the basis of what was said by each partner, about one another and about their relationship. Comparisons at this level brought insights into similarities and differences in perspectives related to smoking cessation, partner support, and perceptions of the risks associated with smoking during pregnancy. It also provided insight into the ways that couples communicate, overall leading to an improved understanding of experiences and perspectives at the dyadic level.

2.7.4.5 Comparing couples

The final step in the process of constant comparison involved comparisons between couples who shared the experience of having one pregnant partner who smoked at the time of becoming pregnant. Questions of comparison such as the following were asked here: what are the differences between couple A and couple B? What are the possible reasons for

64 these differences? On which criteria can these two couples be compared? This step was the most complex as it involved the comparison of four interviews, from two different perspectives (one pregnant female, one male), and required a certain level of aggregation of couple stories whilst also taking into account the individual stories being told. It was valuable however, in allowing for the identification of couple level patterns and for discriminating between different relationships. This was most helpful for achieving the aims of the study.

It is important to note that the steps described above did not form a linear process; rather they were all found in all of the research phases as coding progressed iteratively from the application of initial open codes, to more focused analytic codes, and then finally to inter- related theoretical codes organised within an explanatory model. In this way, with each new interview, the within interview comparisons took place. The comparison within the pair was then completed, and following that the comparison with different couples could be conducted. It was noted however that steps two and five became more important towards the end of the study, with steps one and four being needed more in the early stages of data analysis.