Display Scale in a ‘Document’ perspective : size matters

Abstract

The work summarized in this thesis has its basis in technology to support human collaboration. I have investigated how large, high-resolution display (LaHiRD) technology, implemented using display wall technology (large, tiled displays implemented as one coherent display surface) could support clinical work. Hence, I have worked with the topic of technological support for human collaboration (or –interaction) in a medical context. This thesis is three-tiered; one layer is related to how a certain novel technology, (very-) large-high-resolution displays may be of clinical use. The second layer relates to specific cognitive effects users of the novel technology may experience. The third layer relates to a novel analysis framework for sosiotechnical (STS) systems (LaHiRD technology creates STSs in use). Summarized, I found LaHiRD technology’s most prominent and interesting features to be the possibility for arbitrary sized displays and vast pixel-counts achievable. This affords a wide-range of uses, but is particularly interesting for group work situations and may enable a more ‘natural’ and embodied ‘arena’ for reasoning. In collaboration with the Radiology department at UNN an implementation of a prototype radiology interface for a Display Wall was made. A crude interface was designed, which was presented in a demo for the UNN radiologists and a couple of other invited specialists. This demo was videotaped and transcribed and the main results were extracted from these data, and others from the notes and interviews made in the design process for the radiology interface. It was found that yes: the clinicians were quite positive towards the clinical potential for technology, such as the Display Wall. Focus in future studies should be information design with more diverse and currently (visually-) unavailable information – and specific information to support the workflow and specific cognitive processes of group work-settings. Regarding the Second layer, contemporary research was at this time focusing on cognitive effects of display size. For instance: how does it affect our experience of the documents displayed that size increases? Does increasing size help our problem solving? Does increasing size help some groups of users more than others? Which tasks are affected by display size in this regard? Such questions have been posed and answered during the last decade and some of the results were intriguing for my work as well. In collaboration with Department of Psychology at UiT we found that we could try and figure out how tasks similar to those performed at a Radiology department is affected by display size. We designed an experiment to test how display size affects a spatial ability called ‘mental rotation’ (MR). Mental rotation is the task of deciding whether two images of arm-like structures, made from cubes attached face to face, are the same. This task is intuitively similar to the kind of work performed at a radiology department. ‘Objects’ (organs, body-parts, blood vessels, etc.) are viewed from different angles (‘coronal’, ‘sagittal’, ‘transverse’) and ‘healthy objects’ are compared to ‘pathological’. We designed two separate experiments. Both were a mixed design with Display Size and Angle (-of rotation between the MR stimuli objects) were within-subjects factors, while Sex was between-subjects factor. Our first study included 40 subjects of 4 groups where we alternated the two groups of males/females of which display condition they were tested first in. We presented half of the participants in the first experiment with a hypothesis stating that large displays should yield better performance, while the other half were presented with the opposite hypothesis – that smaller displays provides better performance. We found that females were indeed faster than males on the large display (but no difference in accuracy). However, the group of females who had been presented prior to the experiment with the hypothesis that large displays are better were performing significantly faster than all other three groups (females ‘believing’ that small displays are superior and both male groups). In order to strengthen this finding, or reject the hypothesis that the display size was affecting female performance (and that ‘belief’ alone was making females better), we designed a new experiment where we left out any explicit information regarding hypothesis. In the second experiment we also recruited more subjects in order to provide more evidence to our finding. We had 36 males and 32 females perform the same task as in the first experiment and we improved the research design. We used a high-speed camera to compute – and ‘control’ – a network delay in stimulus onset for the large display condition. This made within-subjects comparison in performance on small contra large display more reliable. Again we found that females significantly outperformed males in the large display condition. On average, females were about 20% faster than males in the large display condition. However, females did not perform faster on the Display Wall than on the laptop display. What we found, rather, was that males and females performed similar in the smaller laptop display condition and that the Display Wall condition had a significant detrimental effect on male performance, actually deteriorating their small-display performance by 20%. In summary, we have found that visually enlarging objects may have a detrimental effect on work-tasks that involve mental rotation of three-dimensional objects – a task that resembles the work typically performed in Radiology departments. This effect was observed with objects about twice the size of typical object sizes used in the traditional Shepard-Metzler MR task (comparing two objects at a time). As for the Third layer of this thesis, this involved establishing a document lens – processing (and ‘extracting) ‘document theory’ and developing a model – in collaboration with Documentation Studies at UiT, for systems analysis. The document model which I have assembled is comprised of 7 components: agent, means, modes, configuration, connection, construction and results (Olsen et al., 2012). This model encompasses all issues that have been a part of this thesis; the agents (Radiologists/other healthcare personnel) the technical infrastructure (means and modes; the ‘what’ and the ‘how’), the perceptual qualities of the Display Wall (how ‘larger’ may not always better – i.e. the perceptual Configuration of the document) and the social affordances (Connection) and finally – the Result (resulting document): the radiology interface (although only a crude prototype). The document model, I found, is a holistic and broad model that arguably encompass traditional ‘physical objects’ (a printed book; a contract) and all novel, digital documents. I have tried to explicate- and place this model, concept and the theory behind in relation to other ‘sociotechnical methodology’. In the Document Analysis (DA), we use the framework of traditional document analysis to try and analyse, or predict novel documents. Analysing present documents (already created), or historical documents may create a basis, or casting mould for experimental analysis. A document analysis, as presented in my work, may well have value as a communicating artefact, or Boundary Object in the requirements phase of systems development and –design, especially for sociotechnical systems where non-technical (non-functional) requirements are important. As for how to utilize DA in this context, the novel document model provides a framework and a template for document analysis.