Heterogeneity is Here to Stay and Semantics is Not About Agreement
- 1. Heterogeneity is Here to Stay and Semantics is not about Agreement Krzysztof Janowicz STKO Lab University of California, Santa Barbara, USA EarthCube All-Hands Meeting Addressing Data Heterogeneity 2014 June 2014 Heterogeneity is Here to Stay and Semantics is not about Agreement K. Janowicz
- 2. The Data Retrieval Problem Is Real Even the major data hubs such as Data.gov still rely on keyword-based search and have unreliable, incomplete, and missing metadata. For this type of retrieval problems, even ’a little semantics goes a long way’ (Hendler 1997). Heterogeneity is Here to Stay and Semantics is not about Agreement K. Janowicz
- 3. Sensemaking is Difficult – Fitness for Puspose is Key There is no shortage of data, but finding data that is fit for a certain purpose is difficult. Data as statements (think RDF) not as truth. Heterogeneity is caused by cultural differences, progress in science, viewpoints, granularity, ... Alchemist Fallacy1; semantics does not come for free. Lack of provenance information Sensemaking requires more powerful semantic technologies and ontologies (compared to IR). 1You cannot transmute base metals into gold and even if you could, gold would not be precious anymore. Recall the data citation discussion. Heterogeneity is Here to Stay and Semantics is not about Agreement K. Janowicz
- 4. Meaningful Analysis and Synthesis is Difficult Ensuring that data is analyzed and combined in a meaningful way is far from trivial. What if the information on how to use the data would come together with these data? Focus on smart data instead of (merely on) smart applications. The purpose of ontologies is not to agree on the meaning of terms but to make the data provider’s intended meaning explicit. A little experiment: The statement all rivers flow into other water bodies is not useful because it is ’true’2, but because...? 2It is not; rivers can flow into the ground or just dry up entirely before reaching another water body. Heterogeneity is Here to Stay and Semantics is not about Agreement K. Janowicz