1. A computer-implemented method of providing a response to a query comprising: receiving a query request, to which a response containing a numerical value is expected, from a querying device; identifying at least one input series as relating to the query request, the or each input series having at least one numerical input measurement; assigning a weighted score to the or each input series identified as relating to the query request; selecting at least one input series from among the input series identified as relating to the query request, the selection being dependent on the weighted score assigned to the or each input series identified as relating to the query request; generating a response to the query request, the response containing a numerical value based on the or on one of the numerical input measurements of the selected at least one input series, thereby providing said response to the querying device.