Online machine learning (OML) is a type of machine learning (ML) in which data is acquired sequentially and utilised to update the best predictor for future data at each step, in contrast to batch learning techniques, which generate the best predictor by learning on the full training data set at once. In comparison to "conventional" machine learning solutions, online machine learning takes a fundamentally different approach, one that recognises that learning environments can (and frequently do) change from second to second. It is employed in cases when the algorithm must adapt dynamically to new patterns in the data or when the data is generated as a function of time. OML is a widely used technique in areas of machine learning when training over the complete dataset is computationally impractical, necessitating the employment of out-of-core algorithms. OML, in its simplest form, is a machine learning technique that ingests a sample of real-time data, one observation at a time.

We revisit the interest of classical statistical techniques for sales forecasting like exponential smoothing and extensions thereof (as Holt's linear trend method). We do so by considering ensemble forecasts, given by several instances of these classical techniques tuned with different (sets of) parameters, and by forming convex combinations of the elements of ensemble forecasts over time, in a robust and sequential manner. The machine-learning theory behind this is called "robust online aggregation", or "prediction with expert advice", or "prediction of individual sequences" (see Cesa-Bianchi and Lugosi, 2006). We apply this methodology to a hierarchical data set of sales provided by the e-commerce company Cdiscount and output forecasts at the levels of subsubfamilies, subfamilies and families of items sold, for various forecasting horizons (up to 6-week-ahead). The performance achieved is better than what would be obtained by optimally tuning the classical techniques on a train set and using their forecasts on the test set. The performance is also good from an intrinsic point of view (in terms of mean absolute percentage of error). While getting these better forecasts of sales at the levels of subsubfamilies, subfamilies and families is interesting per se, we also suggest to use them as additional features when forecasting demand at the item level.

It is well known that a systematic analysis of the pupil size variations, recorded by means of an eye-tracker, is a rich source of information about a subject's cognitive state. In this work we present end-to-end models for the diagnosis of Parkinson's disease (PD) based on the raw pupil size signal. Long-range registration (10 minutes) of the pupil size were collected in scotopic conditions (complete darkness, 0 lux) on 21 healthy subjects and 15 subjects diagnosed with PD. 1-D convolutional neural network models are trained for classification of short-range sequences (10 to 60 seconds of registration). The model provides prediction with high average accuracy on a hold out test set. A temporal analysis of the model performance allowed the characterization of pupil's size variations in PD and healthy subjects during a resting state. Dataset and codes are released for reproducibility and benchmarking purposes.

I did a series of blog posts on different machine learning techniques recently, which sparked a lot of interest. You can see part 1, part 2, and part 3 if you want to learn about classification, clustering, regression, and so on. In that series I was careful to differentiate between a general technique and a specific algorithm like decision trees. Classification, for example, is a general technique used to identify members of a known class like fraudulent transactions, bananas, or high value customers. Read this machine learning post if you need a refresher or are wondering quite what bananas have to do with machine learning.

Your brain may be the best predictor for whether or not you're a musician, a new study finds. Researchers at Finland's Aarhus University used functional magnetic resonance imaging (fMRI) scans to capture images of the brain activity of 18 musicians and 18 non-musicians while they listened to different genres of music. The images revealed that certain brain areas are better predictors for whether we are musically talented: specifically, the frontal and temporal areas of the brain's right hemisphere. Researchers at Finland's Aarhus University used functional magnetic resonance imaging (fMRI) scans to capture images of the brain activity of 18 musicians and 18 non-musicians while they listened to different genres of music The scientists used six varieties of music during the test, including ones representing timbre and rhythm or tonality. Tonality and pulse are the best predictors of musicianship, the scientists noted.

Although compelling assessments have been examined in recent years, more studies are required to yield a better understanding of the several methods where assessment techniques significantly affect student learning process. Most of the educational research in this area does not consider demographics data, differing methodologies, and notable sample size. To address these drawbacks, the objective of our study is to analyse student learning outcomes of multiple assessment formats for a web-facilitated in-class section with an asynchronous online class of a core data communications course in the Undergraduate IT program of the Information Sciences and Technology (IST) Department at George Mason University (GMU). In this study, students were evaluated based on course assessments such as home and lab assignments, skill-based assessments, and traditional midterm and final exams across all four sections of the course. All sections have equivalent content, assessments, and teaching methodologies. Student demographics such as exam type and location preferences are considered in our study to determine whether they have any impact on their learning approach. Large amount of data from the learning management system (LMS), Blackboard (BB) Learn, had to be examined to compare the results of several assessment outcomes for all students within their respective section and amongst students of other sections. To investigate the effect of dissimilar assessment formats on student performance, we had to correlate individual question formats with the overall course grade. The results show that collective assessment formats allow students to be effective in demonstrating their knowledge.

Taste in movies is idiosyncratic, and not linked to the demographic traits that film studios target, a study has found. It also shows that moviegoers' ratings don't always match those of film critics. The survey of more more than 3,000 people found that the best predictor of a non-critics' response to a film was the aggregated evaluations of other non-critics, such as those on the Internet Movie Database (IMDb). The results of a study revealed that there were generally low levels of correlation in movie preferences among non-film critics - in other words, their movie tastes were highly individualistic. 'What we find enjoyable in movies is strikingly subjective - so much so that the industry's targeting of film goers by broad demographic categories seems off the mark,' says Dr Pascal Wallisch, a clinical assistant professor in New York University's Department of Psychology and the senior author of the study.