The present work analyses decision making behaviour in personnel selection. The analysis focuses on the investigation of the relative importance of particular characteristics of the applicant on his or her hirability (applicant competencies, person-organisation and person-job fit, and social capital). Furthermore, it is analysed how firm size and age moderate this relative importance and in how far decision makers possess insight into their own decision making behaviour. The work is structured as follows: In the first chapter, the research topic is introduced, its importance and research gaps are described and the research approach is laid out. Furthermore, a literature review (chapter 2) provides a brief overview of the literature written on staffing in small and / or emerging firms. In chapter 3, I will elaborate that personnel selection is basically a decision making process with three major components: decision cues, criteria, and predictors. The description of selection theory with the interaction of criteria and predictors in the process of predicting future job performance of the applicant as well as a brief overview of selection practices with a vast number of potential decision cues leads to the next chapter. Chapter 4 presents an excursus in this thesis. As the findings of the previous chapter created a particular tension between theory and practice, an empirical pilot investigation was conducted to close that gap and to reconcile both theory and practice. Five case studies in emerging German IT and high-tech companies shed light on the elements to focus on in further research. These case studies also help to reconcile the theory of personnel selection with the special aspects of selection in the IT-context which is the particular focus industry of this thesis. In chapter 5, I continue with laying out the theory of personnel selection and close the theoretical part. I analyse the role and impact of three sets of decision cues: applicant competencies, applicant-organisation fit and applicant networks. This chapter is closed with the generation of a number of hypotheses on the use and importance of these decision cues in personnel selection in emerging high-technology firms. The third part of this thesis describes the empirical research undertaken to further investigate decision making in selection situations and to test the hypotheses. Chapter 6 introduces conjoint analysis as an appropriate means to capture decision policies and to answer the research questions. Variables, research instrument, and research approach are presented. The results of the described experimental survey are laid out in the following chapter 7. After the sample has been described, the data collected is analysed and presented and the hypotheses are tested. The fourth and final part of this thesis comprises the conclusion. In the last chapter, the results are discussed in the light of the previously laid out theory. Both limitations of the study as well as hints for future research are presented.