The invention in a first embodiment comprises a method of utilizing seismic data attributes for interpreting seismic data from a region of the earth's subsurface, in which values are calculated for a plurality of seismic data attributes of said seismic data, and combinations of said calculated values are generated to develop an indication of shaliness of said region of the earth's subsurface. In another embodiment the invention comprises a device, which is readable by a digital computer, having instructions thereon for defining a process and instructing a computer to perform a process for calculating values for seismic data attributes of said seismic data indicative of thinness of subsurface strata, parallelism of subsurface strata, lateral continuity of subsurface strata and continuity consistency of subsurface strata, and generating combinations of calculated values for said seismic data attributes to generate an indication of shaliness of said region of the earth's subsurface.