Machine Learning Coffee Seminars

Machine Learning Coffee Seminars2019-01-14T11:39:04+03:00

About Us

Machine Learning Coffee seminars are weekly seminars held jointly by the Aalto University and the University of Helsinki. The seminars aim to gather people from different fields of science with interest in machine learning. Seminars will be held weekly on Mondays at 9 am – 10 am. The location alternates between Aalto University and the University of Helsinki. At Aalto University, talks will be held in Konemiehentie 2, seminar room T6 and at the University of Helsinki in Kumpula, seminar room Exactum D122 (Gustaf Hällströmin katu 2b), unless otherwise noted. Talks will begin at 9:15 am and coffee will be served from 9:00 am.

Subscribe to our mailing list where seminar topics are announced beforehand.

Upcoming Talks (2019)

June 2019

Generating Captions for Search Results with Lexical and Semantic Features

Date: June 17, 2019

Abstract: In exploratory search, users try to acquire new knowledge or investigate novel data sets. Exploratory search is challenging: users’ lack of domain knowledge can negatively impact their ability to assess the quality of search results. Indeed, as search proceeds, the accumulation of feedback can result in the presented documents no longer being related to the initial search query. Users’ information needs are assumed to be highly dynamic and therefore expected to evolve over time, but this is difficult to distinguish from query drift, where improper feedback has adversely affected results. Unfortunately, in either scenario, users engaged in exploratory search can be unaware of their changing search trajectory.

With these issues in mind, we present Exploratory Search Captions (ESC) inspired by research in image caption generation. ESC is an ensemble method that generates captions by combining semantic and lexical features. Semantic information is derived from a novel sequence-to-sequence autoencoder that performs representation learning on ranked search results. ESC aims to provide a succinct description of ranked search results in order to assure users that their search is proceeding as intended and to alert them when it is not. In the context of scientific literature search, ESC generated 26% more relevant captions than methods from the query expansion literature according to an expert evaluator. All other methods were comparatively noisy, including many more captions that were too generic to be useful.

Speaker: Dorota Glowacka
Affiliation: Professor of Computer Science, University of Helsinki

Place of Seminar: Lecture Hall Exactum D122, University of Helsinki

NOTE: We will have summer break until the end of August.


Samuel Kaski  Professor of Computer Science, Aalto University
Teemu Roos Professor of Computer Science, University of Helsinki
Homayun Afrabandpey Researcher, Aalto University