Modifiable temporal unit problem

In spatial thinking (thus, in solving many geographic tasks), time is a fundamental element. This has been broadly acknowledged and demonstrated in geographic information science literature for decades (Hägerstrand 1970; Thrift 1977, Pequet 1988; Miller and Bridwell 2009). For example, when studying human activities in physical space, or when assessing the environmental impact of geographic processes, temporal aspect is critically important (Meentemeyer 1989; Kraak 2000; Ott & Swiaczny 2001). But how do people decide whether a temporal resolution is appropriate or not to perform the spatio-temporal analysis of a geographic process? This is essentially a question of scale in temporal dimension. In this position paper we treat this question at a conceptual level, drawing a parallel with the well known Modifiable Areal Unit Problem (MAUP), and introducing the term Modifiable Temporal Unit Problem (MTUP). In spatio-temporal analysis of geographic processes, temporal granularity can introduce critical issues (Meentemeyer 1989; Gibson et al. 2000; Hornsby and Egenhofer 2002). These issues are similar to those related to the MAUP (Openshaw and Taylor 1979). The MAUP is a well studied, yet formally unresolved problem (Reynolds 1998; Shawna and Bram 2007). It can introduce strong bias to the interpretation of the statistical hypotheses; even produce false positives or