This is a knowledge sharing group. We want to learn more about machine learning.
There will be two types of sessions: - Go in depth sessions: the objective is the good understanding of the machine learning techniques. These sessions can also be used to learn other closely related areas such as optimization, classic statistics, game theory...
Disclaimer: some topics may require the use of mathematical tools, so one should be opened to working with mathematics.
- Exploratory sessions: the objective is to explain the general/key ideas of techniques and experiences with machine learning.
letgo is a two-sided marketplace to buy and sell second-hand goods locally. Search relevance for local marketplaces faces challenges that are significantly different from the ones in web or e-commerce search: each listing is unique and the catalog is extremely volatile as listings get sold and posted continuously. In addition, listing descriptions, being user generated content, are usually short and noisy.
We will discuss those differences and present the solutions we developed at letgo with two main focuses: How the search platform was designed in order to scale to millions of daily users, and how relevance was improved. We will also survey techniques to improve precision and recall, and how to evaluate offline and online candidate changes in the system.
About the meetup
Multidimensional Scaling (MDS) is a statistic tool for reduction of data dimensionality. In this meet-up, we introduce this method along with some of its applications and use cases.
When the sample size is large, classical algorithms for obtaining MDS suffer from computational problems and it is not possible to get a configuration. A set of algorithms for MDS with Big Data are also presented.
About Cristian Pachón
Cristian Pachón works as a Data Scientist at Softonic, the largest trusted-apps and software platform in the word. He is part of the co-founder team of Barcelona Data Science Society (Badass) as well as an active member of the Machine Learning community, helping and organizing meetups.