While the so-called replication crisis is increasingly discussed and addres sed through reformed research practices and institutional structures, this contribution diagnoses a theory or interpretation crisis and argues that the current emphasis on transparency, reproducibility, and reliability should be complemented by stronger efforts in terms of theory and validity. The article identifies different types of unsystematic (e.g., ad hoc, asymmetric, or trivial) theory building. Furthermore, objects of investigation, measure ments, and findings are not interpreted carefully in the light of sufficiently elaborate and well-justified theoretical concepts or frameworks. Different consequences of such shortcomings are discussed-whether unfruitful or implausible hypotheses are tested or the implications of findings are re main poorly understood or are not critically reflected. Readers are invited to engage not only with methodological literature and previous research, but also with theoretical works and particularly with literature on methods or strategies of theorizing, and to practice theory building based on a clearer understanding of the multiple meanings and functions of theory.