Sampling considerations

Generally, sampling involves selecting members from a population, so that they are representative of that population. The purpose of a qualitative case study is to explore a phenomenon by means of in-depth inquiry. In a smaller organisation that is the subject of a case study, all of the actors might conceivably be interviewed as a 100% sample. In a larger organisation such as Stadtwerke Bielefeld, a sampling becomes a significant issue in research design, whereby the expectation is not to represent the entire population, but to offer deep insights into opinions. On the basis of this understanding, it was decided that the interviewees should be key

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informants, best able to offer research insights. Key informants are characterised by a special position in the organisation, who possess special knowledge and or status and have access to perspectives or observations denied to the researcher. Further, these managers play a key role in the case and therefore are informants from which one is likely to learn most about the issue in question.

In the case of Stadtwerke Bielefeld, members of the first and second management levels were identified as key informants. They all hold a very responsible position, are in charge of fifty to over a hundred employees, and have decision-making authority and considerable work experience with the company. Also they are persons who have been concerned with questions of organisational change before (as I am aware, given that it is local knowledge case). The key informants were selected, because they hold representative knowledge about the case.

To create the sample or selection of interviewees, all key informants in the population were identified and listed in a first step. Due to the limited numbers of managers of the first and second level positions at Stadtwerke Bielefeld, there was no further sampling required (there are two directors and seven heads of business divisions, two heads of staff divisions as well as one director of the distribution grid service company). Instead, all twelve managers were asked to participate in the study. Thereby the aim of the sampling was to select key informants as interview partners and this group of informants was selected as a 100% sample.

The objective for the initial stage of the data collection was to gain at least eight participants for the interviews, due to the small population of identified key informants. When the findings suggested that more interviews would be necessary due to the iterative nature of interviewing for a case study, more interviewees would be acquired. This would be achieved by expanding the group of key informants by including the managing directors and heads of business divisions of the subsidiaries of the Stadtwerke Bielefeld group of companies. As these managers do not operate within the core business of Stadtwerke Bielefeld, they are affected by the need for change in different ways. However, as the companies are integrated financially they do have an interest in the financial stability of the parent company.

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As planned, the identified key informants of Stadtwerke Bielefeld were listed. According to the organisational structure displayed in figure 2 (p. 8), the management board, the heads of business units and staff departments were identified as key informants as well as the managing director of the subsidiary Stadtwerke Bielefeld Netz GmbH, which was unbundled under company law due to legislatory requirements. This formed a total of twelve key informants to be invited to participate in the interviews. Due to the impending retirement of one of the managers, for one management position two persons were asked to participate. Internal consent for the conduction of interviews was obtained on October 15th, 2013 with one of the managing directors in a face-to-face meeting with me. After that a brief description of the research project, the interview guideline and the group of possible interviewees was provided to the managing director, who then informed the designated group of persons on November 11th, 2013. In the following two weeks, I called the designated participants on the phone, offered to provide further general information about the research project, answered potential questions and asked if the person was willing to participate. If the person agreed, a time for the interview was scheduled. Even though the assumed duration of the interview would be about an hour to an hour and a half, a slightly longer time frame was scheduled, to buffer possible delays, to clarify questions beforehand, to explain the interview procedure and to ask for final permission for recording of the interview. The interviews were to take place in the office of each manager, to be undisturbed and to have a natural real-life setting. In accordance with the proposal of Schreier (2012) that phenomena researched can only be interpreted in their unique setting and circumstances, the surrounding of the interview was chosen to be as authentic as possible. As it was assumed, willingness to participate in personal face-to-face interviews was high, and therefore all thirteen persons asked were willing to be interviewed, which made a participation rate of one hundred per cent. The interviews were conducted between November 15th, 2013 and January 29th, 2014. About two to five working days before the interview was to take place, the interview guideline (see annex 1), which included a brief description of the aim of the research and an exemplary definition of organisational readiness for change

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was mailed to the participant via in-house mail. Therewith the interviewee had the opportunity to prepare for the interview and a high level of transparency was ensured. The electronically recorded interviews were passed to professional transcribers, who signed confidentiality agreements beforehand. After the interviews were conducted and electronically recorded, transcripts were drawn up and a printout of each mailed to the interviewee within two weeks from the interview date. This offered the chance for the participants to read through their answers again and correct something, if necessary, and also participants felt valued by the confirmation in a short time. With the consent to the transcript of the participants the process of data collection was completed.

3.6.1 The management sample profile

Thirteen interviews including a pilot interview were conducted. Of the thirteen interviewees, one was female and twelve were male. The high ratio of males in the workforce, with an overall gender balance of 73% male to 27% female (Stadtwerke Bielefeld GmbH, 2013/2014), is skewed even more in favour of males in management positions. The age range was from 42 to 69 with an average of 55.4 years. Most of the respondents were in the age group 51-55. The distribution of age groups, professional education and gender are shown in figure 11:

Figure 11: Characteristics of the management sample

The relatively high average age might be explained by the selection of top management with the highest level of responsibility within Stadtwerke Bielefeld for the interviews, as top management positions are usually filled with experienced

Age Group Respondents Education Respondents Gender Respondents

40-45 1 Commercial 7 Male 12 46-50 1 Technical 5 Female 1 51-55 6 Both 1 56-60 2 61-65 2 66-70 1

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professionals. Consequently, the average duration of professional experience was also high with 30.2 years per person and an average professional experience at Stadtwerke Bielefeld of 20.0 years, with a combined total of 260 years of work experience with the company.

3.6.2 The sample of non-managerial employees

It was initially proposed to the senior management that it would add a valuable dimension to the evaluation of readiness to be able to compare the results of the interviews of managers with the assessments made by non-management employees. However, it was then decided that it was not possible to interview these employees, due to company confidentiality policies. Therefore a short questionnaire-based survey of employees at Stadtwerke Bielefeld was developed and implemented. For this purpose, a questionnaire was designed using only the six statements phrased to function as Likert items about change readiness as discussed cited above (see 3.5.2; annex 1, section II, questions 5, 6 and 9). The statements were formulated in exactly the same way as in the management interview guideline. To test the questionnaire, a project group, of which two persons also participated in the interviews, was asked to pretest and evaluate the statements. The pretesting resulted in slight changes to the wording of the statements (see also figure 5). The questionnaire, a one-pager in its original format, is included as annex 2.

The next step was to randomly select non-managerial employees to participate. It was intended to obtain fifty completed questionnaires as well as to recruit fifty persons to participate in a short workshop to discuss change readiness and other issues not of specific relevance to this research. That was not a statistical determination, as the survey was of a qualitative nature. For that purpose, 70 non- managerial employees of entire Stadtwerke Bielefeld were selected randomly with a SAP HR query by the HR department and were asked to fill out the questionnaire about change readiness. The 70 employees represented about 5.9% of the non- managerial employees of Stadtwerke Bielefeld, based on a population of 1184 non-

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managerial employees (end of 2012). The survey was emailed out by the HR department with an enclosed explanation of the purpose of the survey. The only criterion for selection was non-managerial; profession, age group or other possible selection criteria were not applied. Of the 70 employees who were invited, 65 returned the completed questionnaire. Again, as it was an internal questionnaire, the response rate was expected to be high and a 92.9 % rate was achieved.

Even though the short questionnaire was worded exactly the same as the interview questions to maximise validity and provide a basis for triangulation, there are limitations to comparability, as the setting of the questions was different as part of a face-to-face interview with the managers and a written, emailed questionnaire for the employees. The employee survey was mailed out with a short explanation, so the respondents had the chance to get some clarification of the meaning of the questions. However, the explanation was carefully worded so as not to influence responses by my intervention. Some comments sent back with the survey questionnaires showed that follow-up interviews with these employees would have been interesting. Further comparability is limited due to the differing population size of managers identified as key informants and employees. The procedure of data analysis and the comparison of the management and non-management sample’s answers is described in the next paragraph.