To rationalize the selection of a research methodology, one must understand its philosophical origins and unique characteristics. This process can be challenging in the landscape of evolving qualitative methodologies. Grounded theory is a research methodology with a distinct history that has resulted in numerous approaches. Although the approaches have key similarities, they also have differing philosophical assumptions that influence the ways in which their methods are understood and implemented. The purpose of this discussion paper is to compare and contrast three (...) widely used grounded theory approaches with key distinguishing characteristics, enabling a more thoughtful selection of approach. This work contributes to the existing literature through contrasting classic Glaserian grounded theory, Straussian grounded theory, and constructivist grounded theory in a systematic manner with prominent distinguishing characteristics developed from a review of the literature. These characteristics included historical development, philosophical perspective, role of the researcher, data analysis procedures, perspective of the grounded theory, and strengths/critique. Based on this analysis, three considerations are proposed to direct the methodological choice for a study: purpose, philosophy, and pragmatics. Understanding the similarities and differences in the grounded theory approaches can facilitate methodological transparency and determine the best fit for one's study and worldview as a researcher. (shrink)