Denotation and connotation in the human-computer interface: The ‘Save as...’ command

This paper presents a semiotic technique as a means of exploring meaning and understanding in interface design and use. This is examined through a study of the interaction between the ‘file’ metaphor and ‘save as’ command metaphor. The behaviour of these (from a functional or computational basis) do not exactly match, or map onto, the meaning of the metaphor. We examine both the denotation of a term to the user, i.e. its literal meaning to that person, and the term’s connotations, i.e. any other meanings associated with the term. We suggest that the technique applied is useful in predicting future problems with understanding the use of metaphor at the interface and with designing appropriate signification for human-computer interaction. Variation in connotation was expected but a more fundamental difference in denotation was also uncovered. Moreover, the results clearly demonstrate that consistency in the denotation of a term is critical in achieving a good user understanding of the command

Social network ties beyond nonredundancy: An experimental investigation of the effect of knowledge content and tie strength on creativity

This is the author accepted manuscript. The final version is available from American Psychological Association via the DOI in this record.Social network research emphasizes the access to nonredundant knowledge content that network ties provide. I suggest that some content is more beneficial than others and that tie strength may affect creativity for reasons other than the associated structure. That is, tie strength may affect how individuals process nonredundant knowledge. I investigate 2 types of knowledge content-information (i.e., facts or data) and frames (i.e., interpretations or impressions)-and explore whether tie strength influences their effect on creativity. Drawing on creativity theory, I employ an experimental design to provide greater theoretical clarity and to isolate causality. According to the results from 2 studies, distinct frames received from contacts facilitate creativity, but the effect of distinct information is more complex. When individuals receive distinct information from strong ties, it constrains creativity compared to distinct frames. Content from weak ties appears to facilitate creativity across all scenarios. The results of mediated moderation analysis indicate the effect of framing versus information for strong ties is driven by decision-making time, as an indicator of cognitive expansion

Toward Effective Hospital Utilization Management

The challenges presented by managed care ar rangements and third-party utilization controls have led hospitals to strengthen internal utilization man agement programs. This article reports findings from a set of case studies on how hospitals have adapted their utilization management programs to their en vironments. While knowledge acquired from case studies should not be overgeneralized, the findings of these studies suggest some lessons that merit consid eration by hospitals advancing their own programs in utilization management.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66618/2/10.1177_0885713x9200700407.pd

Estimation under group actions: recovering orbits from invariants

Motivated by geometric problems in signal processing, computer vision, and structural biology, we study a class of orbit recovery problems where we observe very noisy copies of an unknown signal, each acted upon by a random element of some group (such as Z/p or SO(3)). The goal is to recover the orbit of the signal under the group action in the high-noise regime. This generalizes problems of interest such as multi-reference alignment (MRA) and the reconstruction problem in cryo-electron microscopy (cryo-EM). We obtain matching lower and upper bounds on the sample complexity of these problems in high generality, showing that the statistical difficulty is intricately determined by the invariant theory of the underlying symmetry group. In particular, we determine that for cryo-EM with noise variance $\sigma^2$ and uniform viewing directions, the number of samples required scales as $\sigma^6$. We match this bound with a novel algorithm for ab initio reconstruction in cryo-EM, based on invariant features of degree at most 3. We further discuss how to recover multiple molecular structures from heterogeneous cryo-EM samples.Comment: 54 pages. This version contains a number of new result