The Spanish organizers por un lado, por otro lado and discursive overmarking: An experimental study

The Spanish correlative pair por un lado (Eng. ‘on the one hand’) and por otro lado (Eng. ‘on the other hand’) fulfill an informative structuring function: it presents two subcomments and organizes them under the same topic. Its procedural meaning does not provide a clear instruction on the argumentative orientation of the cohesive segments. Thus, they can be used both in argumentatively co-oriented and anti-oriented contexts, depending on the argumentative orientation raised by the conceptual words that make up the segments in the discourse. However, two self-paced reading experiments (grammatical judgement and production) that were carried out with 95 and 60 native speakers of Spanish, respectively, show that the degree of acceptability differs according to whether this correlative pair of markers is used in contexts of argumentative co-orientation or anti-orientation. Results suggest that the use of this pair in argumentatively co-oriented segment may result in overmarking if the volume of information is not relevant.