This paper focuses on some of the major methodological and theoretical problems raised by the fact that there are currently no appropriate notation tools for analyzing and describing signed language texts. We propose to approach these problems taking into account the fact that all signed languages are at present languages without a written tradition. We describe and discuss examples of the gloss-based notation that is currently most widely used in the analysis of signed texts. We briefly consider the somewhat paradoxical problem posed by the difficulty of applying the notation developed for individual signs to signs connected in texts, and the more general problem of clearly identifying and characterizing the constituent units of signed texts. We then compare the use of glosses in signed and spoken language research, and we examine the major pitfalls we see in the use of glosses as a primary means to explore and describe the structure of signed languages. On this basis, we try to specify as explicitly as possible what can or cannot be learned about the structure of signed languages using a gloss-based notation, and to provide some indications for future work that may aim to overcome the limitations of this notation.