34,296 research outputs found
Opening the Black Box: Explaining the Process of Basing a Health Recommender System on the I-Change Behavioral Change Model
Recommender systems are gaining traction in healthcare because they can tailor recommendations
based on users' feedback concerning their appreciation of previous health-related messages. However,
recommender systems are often not grounded in behavioral change theories, which may further increase
the effectiveness of their recommendations. This paper's objective is to describe principles for designing
and developing a health recommender system grounded in the I-Change behavioral change model that
shall be implemented through a mobile app for a smoking cessation support clinical trial. We built upon
an existing smoking cessation health recommender system that delivered motivational messages through a
mobile app. A group of experts assessed how the system may be improved to address the behavioral change
determinants of the I-Change behavioral change model. The resulting system features a hybrid recommender
algorithm for computer tailoring smoking cessation messages. A total of 331 different motivational messages
were designed using 10 health communication methods. The algorithm was designed to match 58 message
characteristics to each user pro le by following the principles of the I-Change model and maintaining the
bene ts of the recommender system algorithms. The mobile app resulted in a streamlined version that aimed
to improve the user experience, and this system's design bridges the gap between health recommender
systems and the use of behavioral change theories. This article presents a novel approach integrating
recommender system technology, health behavior technology, and computer-tailored technology. Future
researchers will be able to build upon the principles applied in this case study.European Union's Horizon 2020 Research and Innovation Programme under Grant 68112
Predictive User Modeling with Actionable Attributes
Different machine learning techniques have been proposed and used for
modeling individual and group user needs, interests and preferences. In the
traditional predictive modeling instances are described by observable
variables, called attributes. The goal is to learn a model for predicting the
target variable for unseen instances. For example, for marketing purposes a
company consider profiling a new user based on her observed web browsing
behavior, referral keywords or other relevant information. In many real world
applications the values of some attributes are not only observable, but can be
actively decided by a decision maker. Furthermore, in some of such applications
the decision maker is interested not only to generate accurate predictions, but
to maximize the probability of the desired outcome. For example, a direct
marketing manager can choose which type of a special offer to send to a client
(actionable attribute), hoping that the right choice will result in a positive
response with a higher probability. We study how to learn to choose the value
of an actionable attribute in order to maximize the probability of a desired
outcome in predictive modeling. We emphasize that not all instances are equally
sensitive to changes in actions. Accurate choice of an action is critical for
those instances, which are on the borderline (e.g. users who do not have a
strong opinion one way or the other). We formulate three supervised learning
approaches for learning to select the value of an actionable attribute at an
instance level. We also introduce a focused training procedure which puts more
emphasis on the situations where varying the action is the most likely to take
the effect. The proof of concept experimental validation on two real-world case
studies in web analytics and e-learning domains highlights the potential of the
proposed approaches
Spatial Distributions of Multiple Dust Components in the PPN/PN Dust Shells
We investigate spatial distributions of specific dust components in the
circumstellar shells of a proto-planetary nebula candidate, HD 179821, and a
planetary nebula, BD3639, by means of spectral imaging. With
high-resolution ground-based images and ISO spectra in the mid-infrared, we can
derive ``dust feature only'' maps by subtracting synthesized continuum maps
from the observed images at the feature wavelength. Such spatially detailed
information will help to develop models for the evolution of dust grains around
evolved stars.Comment: 4 pages + 7 figures, to appear in the proceedings of the conference,
"Post-AGB Objects (proto-planetary nebulae) as a Phase of Stellar Evolution",
Torun, Poland, July 5-7, 2000, eds. R. Szczerba, R. Tylenda, and S.K. Gorny.
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