  Spreadsheet programs, artifacts developed by non-programmers, are used for a
variety of important tasks and decisions. Yet a significant proportion of them
have severe quality problems. To address this issue, our previous work
presented an interval-based testing methodology for spreadsheets.
Interval-based testing rests on the observation that spreadsheets are mainly
used for numerical computations. It also incorporates ideas from symbolic
testing and interval analysis. This paper addresses the issue of efficiently
debugging spreadsheets. Based on the interval-based testing methodology, this
paper presents a technique for tracing faults in spreadsheet programs. The
fault tracing technique proposed uses the dataflow information and cell marks
to identify the most influential faulty cell(s) for a given formula cell
containing a propagated fault.
