Methodology I: Task Analysis - Foundations for Designing User-Centered Systems - page 311

1. Interviews
2. Concept (or card) sorting
3. Verbal reports
4. Cognitive walkthroughs
5. GOMS (described in more detail below).
The choice of methods is influenced by factors such as the objectives of the
CTA, the available resources, the types of tasks involved, and the skills of the
person doing the CTA.
Once the data for a CTA has been collected, the results from the various
methods have to be compiled and interpreted. The results of the CTA should
provide details about the cognitive aspects of how tasks are performed, as well as
details of the information and knowledge needed to perform those tasks and how
that information and knowledge are used.
11.4.2 Example Application of CTA
Baxter et al. ( 2005 ) carried out a case study of work in a neonatal intensive care
unit where a new decision support system (Fuzzy Logic Respiratory Neonatal Care
Expert, FLORENCE) was being developed. FLORENCE was intended to help
clinical staff make decisions about changes to the mechanical ventilator that is
used to treat respiratory distress syndrome (RDS) in premature babies. It was
important that the introduction of FLORENCE did not adversely affect the
dependability of the delivery of care in the unit, and that it was acceptable to users.
A CTA was therefore carried out using lightweight rich pictures analysis (Monk
1998 ), the critical decision method (CDM; Klein et al. 1989 ), and observation.
Task analysis methods, in general, pay little attention to the context in which
the tasks are carried out; rich pictures analysis provides a way to take account of
that context, although it is quite novel for it to be included as part of a CTA. In this
case study, a rich pictures analysis was carried out to capture details about the
context in which FLORENCE was to be deployed. Data was collected using semi-
structured interviews to identify the roles, responsibilities, and concerns of eight
members of staff working in the unit, including the staff that provide adminis-
trative support in the unit. The analysis also showed how staff communicate and
interact with members of staff who work in other parts of the hospital, such as the
test laboratories. The importance of communication within the unit was also
identified, since it forms the basis for clinical care of the babies. Furthermore, the
central role of the various patient records was highlighted: FLORENCE would
have to find some way to produce appropriate records.
The CDM was used to analyze how clinical staff make decisions about any
changes that need to be made to the settings of the mechanical ventilators used to
treat the babies. It is critical that these decisions are correct and timely, otherwise
they can seriously adversely affect the babies' health. The basic steps of the CDM