Replication and the search for the laws in the geographic sciences

Replication is a means of assessing the credibility and generalizability of scientific results, whereby subsequent studies independently corroborate the findings of initial research. In the study of geographic phenomena, a distinct form of replicability is particularly important–whether a result obtained in one geographic context applies in another geographic context. However, the laws of geography suggest that it may be challenging to use replication to assess the credibility of findings across space and to identify new laws. Many geographic phenomena are spatially heterogeneous, which implies they exhibit uncontrolled variance across the surface of the earth and lack a characteristic mean. When a phenomenon is spatially heterogeneous, it may be difficult or impossible to establish baselines or rules for study-to-study comparisons. At the same time, geographic observations are typically spatially dependent, which makes it difficult to isolate the effects of interest for cross-study comparison. In this paper, we discuss how laws describing the spatial variation of phenomena may influence the use of replication in geographic research. Developing a set of shared principles for replication assessment based on fundamental laws of geography is a prerequisite for adapting replication standards to meet the needs of disciplinary subfields while maintaining a shared analytical foundation for convergent spatial research.