125,407 research outputs found
Modeling Human Visual Search Performance on Realistic Webpages Using Analytical and Deep Learning Methods
Modeling visual search not only offers an opportunity to predict the
usability of an interface before actually testing it on real users, but also
advances scientific understanding about human behavior. In this work, we first
conduct a set of analyses on a large-scale dataset of visual search tasks on
realistic webpages. We then present a deep neural network that learns to
predict the scannability of webpage content, i.e., how easy it is for a user to
find a specific target. Our model leverages both heuristic-based features such
as target size and unstructured features such as raw image pixels. This
approach allows us to model complex interactions that might be involved in a
realistic visual search task, which can not be easily achieved by traditional
analytical models. We analyze the model behavior to offer our insights into how
the salience map learned by the model aligns with human intuition and how the
learned semantic representation of each target type relates to its visual
search performance.Comment: the 2020 CHI Conference on Human Factors in Computing System
All mixed up? Finding the optimal feature set for general readability prediction and its application to English and Dutch
Readability research has a long and rich tradition, but there has been too little focus on general readability prediction without targeting a specific audience or text genre. Moreover, though NLP-inspired research has focused on adding more complex readability features there is still no consensus on which features contribute most to the prediction. In this article, we investigate in close detail the feasibility of constructing a readability prediction system for English and Dutch generic text using supervised machine learning. Based on readability assessments by both experts
and a crowd, we implement different types of text characteristics ranging from easy-to-compute superficial text characteristics to features requiring a deep linguistic processing, resulting in ten
different feature groups. Both a regression and classification setup are investigated reflecting the two possible readability prediction tasks: scoring individual texts or comparing two texts. We show that going beyond correlation calculations for readability optimization using a wrapper-based genetic algorithm optimization approach is a promising task which provides considerable insights in which feature combinations contribute to the overall readability prediction. Since we also have gold standard information available for those features requiring deep processing we are able to investigate the true upper bound of our Dutch system. Interestingly, we will observe that the performance of our fully-automatic readability prediction pipeline is on par with the pipeline using golden deep syntactic and semantic information
Implicit Measures of Lostness and Success in Web Navigation
In two studies, we investigated the ability of a variety of structural and temporal measures computed from a web navigation path to predict lostness and task success. The user’s task was to find requested target information on specified websites. The web navigation measures were based on counts of visits to web pages and other statistical properties of the web usage graph (such as compactness, stratum, and similarity to the optimal path). Subjective lostness was best predicted by similarity to the optimal path and time on task. The best overall predictor of success on individual tasks was similarity to the optimal path, but other predictors were sometimes superior depending on the particular web navigation task. These measures can be used to diagnose user navigational problems and to help identify problems in website design
MOOCs Meet Measurement Theory: A Topic-Modelling Approach
This paper adapts topic models to the psychometric testing of MOOC students
based on their online forum postings. Measurement theory from education and
psychology provides statistical models for quantifying a person's attainment of
intangible attributes such as attitudes, abilities or intelligence. Such models
infer latent skill levels by relating them to individuals' observed responses
on a series of items such as quiz questions. The set of items can be used to
measure a latent skill if individuals' responses on them conform to a Guttman
scale. Such well-scaled items differentiate between individuals and inferred
levels span the entire range from most basic to the advanced. In practice,
education researchers manually devise items (quiz questions) while optimising
well-scaled conformance. Due to the costly nature and expert requirements of
this process, psychometric testing has found limited use in everyday teaching.
We aim to develop usable measurement models for highly-instrumented MOOC
delivery platforms, by using participation in automatically-extracted online
forum topics as items. The challenge is to formalise the Guttman scale
educational constraint and incorporate it into topic models. To favour topics
that automatically conform to a Guttman scale, we introduce a novel
regularisation into non-negative matrix factorisation-based topic modelling. We
demonstrate the suitability of our approach with both quantitative experiments
on three Coursera MOOCs, and with a qualitative survey of topic
interpretability on two MOOCs by domain expert interviews.Comment: 12 pages, 9 figures; accepted into AAAI'201
Exploring Young Students' Functional Thinking
The Early Years Generalising Project (EYGP) involves Australian Years 1-4 (age 5-9) students and investigates how they grasp and express generalisations. This paper focuses on data collected from six Year 1 students in an exploratory study within a clinical interview setting that required students to identify function rules. Preliminary findings suggest that the use of gestures (both by students and interviewers), self-talk (by students), and concrete acting out, assisted students to reach generalisations and to begin to express these generalities. It also appears that as students become aware of the structure, their use of gestures and self- talk tended to decrease
An investigation into the application of Claims Analysis to evaluate usability of a digital library interface
There is a need for tools that help developers evaluate the usability of digital library interfaces. The potential for using Claims Analysis to help developers in this way has been investigated in three linked case studies. The first explored the design rationale of an existing design with its developers. This showed that they had considered positive consequences for novice uses but that they found it difficult to identify negative effects. The second study explored the detailed design of an add-on feature. A scenario and sample claims were introduced to evaluate exploratory use within an action cycle of planning, execution and evaluation. This framework provided an effective stimulus to enable the developers to evaluate the design and explore opportunities for redesign. Finally, some novice users explored the digital library and the findings from this were used to validate a user scenario and claims
- …