The aim of this book is to explain the philosophical foundations, specific techniques, common evidentiary sources, and standards and best practices of process tracing in order to reduce the risks of making inferential errors in the analysis of historical cases.
"The essential meaning that the term process tracing has retained from its origins in cognitive psychology is that it refers to the examination of intermediate steps in a process to make inferences about hypotheses on how that process took place and whether and how it generated the outcome of interest. In previous work together with George (George and Bennett, 2005: 6), one of us defined process tracing as the use of “histories, archival documents, interview transcripts, and other sources to see whether the causal process a theory hypothesizes or implies in a case is in fact evident in the sequence and values of the intervening variables in that case.” We added that “the process-tracing method attempts to identify the intervening causal process - the causal chain and causal mechanism - between an independent variable (or variables) and the outcome of the dependent variable” (George and Bennett, 2005: 206)."
Source: Process Tracing: From Philosophical Roots to Best Practices p5.
Bennett A & Checkel J T, (2012), Process Tracing: From Philosophical Roots to Best Practices, Department of Government, Georgetown University, Washington, DC, School for International Studies, Simon Fraser University, Vancouver, BC.Retrieved from http://www.prio.no/sptrans/778821635/PT-MS-Chapter1.0212.pdf