Learning linked data, one year at a time


Jack O’Malley


Learning to understand and use linked data presents challenges to both students and teachers. By linked data, we mean the processes, standards, and technologies that people use to make semantic information, such as factual statements, comprehensible to machines. Linked data enables interoperability, allowing users to search multiple databases at once. This interoperability results from a specific format of structured data. While it may seem like a highly technical concept, we constantly create structured data when we use digital technology. Linked data particularly benefits from community generated data, so facilitating the education and empowerment of new users has become an imperative for the field. This report explores how a timeline visualization might facilitate the rapid education of users interested in learning about linked data.

The report uses the web tool Timeline JS. My content comes largely from Wikipedia, Wikimedia Commons, and media licensed under Creative Commons. Selecting openly licensed and accessible media aligns my visualization with the spirit and practice of linked open data.

View my timeline!


To create this visualization, I used the step-by-step tutorial provided by the Knight Lab for their Timeline JS web tool. Timeline JS uses a Google spreadsheet to populate a sleek, professional timeline visualizing events based on their date, text, and media. First the tutorial asks users to copy the spreadsheet template and publish it to the web, which allows the tool to grab the URL and visualize its contents. Feeding that Google URL to the Timeline JS website returns another link, which users can click on to view their visualization. 

Then the research process begins. As users fill out the required fields (the start date) and optional fields (the headlines and media), the timeline quickly fills with chronologically arranged images and descriptive text. I found that the simple and intuitive process allowed me to focus on the content of my timeline rather than fuss with getting the visualization to display properly. 


In designing my visualization, I wanted to think critically about how the three basic units of time, text, and visual media could work together to create a comprehensible narrative. For instance, in selecting visual media such as diagrams, code, or visualizations that had minimal accompanying explanatory text, I assumed that most viewers had heard the phrases linked data or semantic web before and perhaps seen one or more of these images. My goal was to empower those with some knowledge to draw logical conclusions about the nature, purpose, and applications of linked data without further extensive explanation while sparking the curiosity of those who knew less. 

Here are a few of the slides from my timeline, followed by a discussion of whether or not they achieve their goals.

This opening slide does little to communicate anything about linked open data, and I question what it does to set up a narrative about the ideas and processes behind the technology. In the descriptive text, I included a link to the famous article introducing the idea of linked data. Using visual tools to decode the information from that article would probably better leverage the visualization format.  

This screenshot demonstrates several qualities I see as strengths of Timeline JS. First, the image shows the progression from code, to platform, to user-generated visualization in such a way that, without any additional text, someone might get the gist of how this technology works. Although the visualization itself comes from 2021, the little chronological sleight of hand serves to compress the history of the Wikidata Query Service. In fact, I felt confident I could keep text to a minimum here, which I almost always see as a benefit. Timeline JS also displays the timeline in grey at the bottom of the screen, clearly showing how these events follow or overlap with one another both logically and chronologically.

My concluding slide depicts a Google knowledge panel and explains the image’s connection to the Google Knowledge Graph, a massive proprietary linked data knowledge base. From a narrative perspective, this slide should surprise viewers by connecting a novel topic, linked data, to a fairly ubiquitous feature of everyday digital life. Supposing that most people ask of the knowledge panels “how do they work” and “where does the information come from,” viewers of this visualization should now have enough information to formulate an answer.


I found that timelines provide an effective visual tool for thinking about technology, both conceptually and technically. In his book The Information, James Gleick deploys narrative and biography to explore the concepts of data, information, and computation. This timeline (somewhat) mimics how a rich conceptual narrative like Gleick’s might look if both time and visual images accompanied it. This accessible timeline tool might allow more storytellers to utilize the dynamic interplay of time and imagery into their explanation of some of the complex, technical elements of visualization.

As an experiment, I included a final slide that links out to the Google sheet used for the timeline. In theory, this slide could challenge a weakness I saw in the timeline visualization: the relative passivity of the viewer clicking through slides. Whether or not the experiment successfully or appropriately invites participation (it undermines preservation and security), the recursive link should raise questions about how creators can dominate the information narrative when they design a timeline. In other projects, I would like to further develop this element of openness in visualization. 

More Information

The Programming Historian Introduction to Linked Open Data

Wikidata: Introduction to Wikidata

IBM: What is a Knowledge Graph?