Requirements Fixation

Author(s): Rahul Mohanani, Paul Ralph, and Ben Shreeve
Venue: International Conference on Software Engineering
Date: 2014

Type of Experiement: Controlled Experiment
Sample Size: 42
Class/Experience Level: Graduate Student, Professional
Participant Selection: Solicitation using relevant student mailing lists at management and engineering programs at authors' university
Data Collection Method: Observation, Project Artifact(s)


This paper presents work related to Requirements Engineering (RE). It is widely accepted that both an understanding of system desiderata, or system requirements, and design creativity are key factors to success in software engineering. However, cognitive biases play a role in problematic requirements engineering. These cognitive biases led the authors to develop a theory of "requirements fixation: the tendency to disproportionately focus on desiderata that are explicitly framed as requirements." In order to attempt to begin the evaluation of this theory, the authors conducted a study to investigate the possibility that the way the concept of system desiderata is framed can have an affect on creativity in system design. Forty two people were randomly assigned to two equally sized groups, Group A and Group B. Both groups were given almost the exact same prompt to complete a task in one hour, except for a few words. Each group was tasked with developing a design concept for a mobile application to encourage healthy living, but Group A was expected to produce a "requirements specification" while Group B was asked to produce a "list of ideas." The designs were then shuffled randomly and graded by two expert judges that had a reasonable agreement and reliability level.

The results found a significant relationship between the phrasing of desiderata and the level of creativity from the designs. Group A reported significantly greater importance of specification and on average, produced less creative concept designs. This result suggests that framing desiderata as "requirements" significantly increased fixation on requirements and can diminish creativity. Designers are typically sensitive to how desiderata is framed; "requirements" are treated as definitive goals while "ideas" are treated with skepticism in mind. This does not mean that the term "ideas" should be used instead of "requirements" in all cases. This study only suggests that innovation has the potential to be stifled with the term "requirement," which may or may not be the best term to use depending on the needs of the system to be designed.