A Statistical Evaluation of Thin Slice Size

Program slicing is a technique which supports program comprehension. Program slicing extracts all statements — called a program slice — that may affect a certain statement. However, program slicing is not useful if an analysis target program is too large since program slices of such a program are also often too large. Thin slicing is a technique reducing the size of program slice by extracting only statements producing data which is used by a selected statement. However, the size of Thin Slice in general has not been revealed. In this paper, we computed Thin Slices for every data-flow path in 7 Java programs, and then performed statistical evaluation. As a result, the average size of Thin Slice is 2.1% of a program. Furthermore, 60 to 80% of Thin Slices are 0.1% or less.