Evaluating library software and its fitness for purpose

Purpose - To adapt general principles used for evaluating software quality to more specific requirements characteristic of information retrieval and educational applications in library environments. Design/methodology/approach - A conceptual paper based on existing software evaluation models, but one which tries to add some important refinements to key aspects of these received concepts. Findings - That the application of engineering concepts to technologically mediated tasks where crucial system outputs consist of the facilitation of specific mental events in the user of the system (e.g. ``learning outcomes'') can be problematic. In such scenarios it may be valuable to avoid incorporating the production of specific mental events into the ``objective functionality'' of the software in question. Rather, it is suggested that the creation of these outputs should be left to the user, not to the mechanised routines of the system (i.e. these mental system outputs should be facilitated by the system as part of the ``subjective functionality'' of the overall design). Research limitations/implications - These are purely conceptual approaches to library and e-learning software that should be tested by practical case study investigation (e.g. comparative user evaluations both of software designed along general quality models standards, and of software designed to the model suggested here). Practical implications - You can get better results in terms of human outputs and benefits (i.e. better learning outcomes, or a higher level of engagement with effective information retrieval) by means of simple, minimalist implementations of information technology and educational technology-based systems. Originality/value - This library and information science paper attempts to use ideas from software engineering and software evaluation to create an original perspective on real-life problems in the sphere of information retrieval technology and educational technology.