Determinación de la capacidad de eliminación del H 2 S

A questionnaire (appendix 3) was designed that consists of two parts. The development of the questionnaire is mainly based on the empirical study of Hachmeister (2007) in chapter 3.1.5. This study analysed the decision criteria of 3.600 pupils in their final school year entering university in Germany. For this study Hachmeister (2007) considered the existing research at that point of time and adapted the studies of Guggenberger (1991), Bock (1991), Tutt (1991) and Binsardi and Ekwulugo (2003) (chapter 3). Thus, it is one of the largest seminal studies in the area of prospective students’ decision making criteria in Germany. In the next step three expert interviews were conducted where the decision criteria used in the study of Hachmeister (2007) had to be evaluated. Based on the experts’ evaluations these decision criteria were ex- tended and adapted for the purpose of this study. The aims of this study were to identify the most important students’ expectations and experiences of undergraduate students, their rele- vant selection and evaluation criteria and specific types of students to recruiting to private universities.

Some criteria mentioned in previous studies (chapter 3.1) were excluded. Due to the specific conditions of the German education market, for example the vast majority of German students choose a university that is close to their parents’ home (Hachmeister, 2007). The same applies to tuition fees which are not relevant for state universities and highly regulated at private uni- versities as they are not-for profit organisations. Since these factors can therefore hardly be in- fluenced by university marketers, they were not included in the questionnaire.

The first part of the questionnaire pointed out the importance of selection criteria by choosing an institution and the second part emphasised the importance of criteria from students’ eval- uation perspective. For both parts 11 criteria based on the literature review (chapter 3) and

63 expert evaluations (chapter 6.2) were chosen. Also the questionnaire considered personal de- mographics such as age, gender, links to private institutions, background of the parents, em- ployment status of parents, work experience of the student, city of origin and nationality. The questionnaire was tested in a pilot study with 25 students and subsequently improved to in- crease validity. Especially some misleading questions were rephrased. Table 14 shows the relevant student criteria being named and discussed in the considered research (chapter 3) as well as in the expert evaluations (chapter 6.2) and therefore included in the study.

Table 14. Considered student selection criteria for the questionnaire Number Student Selection Criteria Studies

1 Image of the Institution Hachmeister (2007); Expert evaluations: Prof. Dr. Holtbrügge; Prof. Dr. Berg

2 Academic Reputation Binsardi and Ekwulugo (2003); Hachmeister

(2007); Expert evaluation: Dr. Lobin; Prof. Dr. Holtbrügge; Prof. Dr. Berg

3 Research Reputation Binsardi and Ekwulugo (2003); Expert evaluation:

Prof. Dr. Berg

4 University Fair-Positive Impression Bock (1991); Tutt (1997); Expert evaluation: Dr. Lobin; Prof. Dr. Berg

5 Recommended by Friends Guggenberger (1991); Tutt (1997)

6 Ranking of the Institution Tutt (1997); Expert evaluations: Prof. Dr. Holt- brügge; Prof. Dr. Berg

7 Reputation of the Professors Expert evaluation Prof. Dr. Berg

8 Fluctuation Rate of Lecturers Expert evaluations: Prof. Dr. Holtbrügge; Prof. Dr. Berg

9 Employability after Graduation Guggenberger (1991); Binsardi and Ekwulugo (2003); Hachmeister (2007); Expert evaluations: Dr. Lobin; Prof. Dr. Holtbrügge; Prof. Dr. Berg

10 Close links to Companies Guggenberger (1991); Expert evaluations: Dr.

Lobin; Prof. Dr. Holtbrügge; Prof. Dr. Berg

11 Very good Facilities Binsardi and Ekwulugo (2003); Hachmeister

(2007); Tutt (1991); Expert evaluations: Dr. Lobin; Prof. Dr. Holtbrügge; Prof. Dr. Berg

64 4.3 Time Horizon and Data Collection

The next step of the research process is the selection of a suitable time horizon. The time horizon is interrelated to the research strategy and determines if datais collected from various respndents at one point of time (cross-sectional) or from one respondent at various points of time (longitudinal).

Two time horizon strategies can be distinguished. A longitudinal time horizon is character- ised by multiple observations of a research problem and the development of the research pro- ject over a longer period of time (Hasset and Paavilainen, 2013). An example of the latter is change processes in companies (Kusterer, 2008). While this thesis aims to compare expecta- tions and experiences before and after entering a higher education institution, a longitudinal design would be appropriate. However, this would be confronted with several challenges. First, it would be difficult to identify future students of state and private universities before they entered this institution. Second, longitudinal studies require a panel design, i.e. the same students should participate in the study at two different points of time. In the case of this study, a time frame of at last one year would be required that allows students to make suffi- cient experiences with various lecturers and professors, examinations, student services, for- eign offices and other relevant departments and services. Such a long time frame, however, would make it difficult to administer the survey and to ensure an acceptable response rate. Therefore, a quasi longitudinal strategy will be used by asking students to report about their expectations before and experiences after they entered a higher education institution.

Cross-sectional designs are useful for snapshots of a research problem. They are often used in surveys and are appropriate to analyse causal relationships between various dependent and independent variables (Scandura and Williams, 2002). Since this study aims at exploring the relevance of various selection criteria and their relationship with demographic characteristics, such as age and gender of students a cross-sectional design is regarded as appropriate. More- over, it allows for comparing students at different higher education institutions, i.e. state and private universities. The core of the research onion is the selection of appropriate methods of data collection and analysis. This involves choosing suitable research objects and partici- pants (sampling). Different methods are possible to collect appropriate data. One method is the observation of a research problem or participants of a research project. The observation method supports empirical learning from an external perspective (Kusterer, 2008, 83). Anoth- er method to collect data for a research project is interviews. This qualitative technique in-

65 volves a direct interaction with the participants in the research project. It can be distinguished between standardised and semi-standardised interviews (Glaser and Strauss, 2012). Standard- ised interviews include a fixed interview approach where participants cannot deviate from the interview guide. Thus, this interview technique is very structured and planned. On the contra- ry, a semi-structured interview allows the participant and the researcher to differ from the in- terview guide. An advantage of semi-structured interviews is that aspects can be discussed which were not regarded as relevant at the beginning of the research process (Saunders et al., 2012). As this aspect is also relevant for this study, a semi-structured approach is also used for the expert interviews. The subsequent survey is than based on a quantitative research ap- proach. However, the appropriate quantitative data collection for this study was done by ques- tionnaires and followed the survey strategy.