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This first paper in a series describes the design of a study testing whetherpre-appearance signatures of solar magnetic active regions were detectableusing various tools of local helioseismology. The ultimate goal is tounderstand flux-emergence mechanisms by setting observational constraints onpre-appearance subsurface changes, for comparison with results from simulationefforts. This first paper provides details of the data selection andpreparation of the samples, each containing over 100 members, of twopopulations: regions on the Sun that produced a numbered NOAA active region,and a "control" sample of areas that did not. The seismology is performed ondata from the GONG network; accompanying magnetic data from SOHO/MDI are usedfor co-temporal analysis of the surface magnetic field. Samples are drawn from2001 -- 2007, and each target is analyzed for 27.7 hr prior to an objectivelydetermined time of emergence. The results of two analysis approaches arepublished separately: one based on averages of the seismology- andmagnetic-derived signals over the samples, another based on DiscriminantAnalysis of these signals, for a statistical test of detectable differencesbetween the two populations. We include here descriptions of a newpotential-field calculation approach and the algorithm for matching sampledistributions over multiple variables. We describe known sources of bias andthe approaches used to mitigate them. We also describe unexpected bias sourcesuncovered during the course of the study and include a discussion ofrefinements that should be included in future work on this topic.

Helioseismology of Pre-Emerging Active Regions I: Overview, Data, and Target Selection Criteria