- Download this repository as a .zip file cy clicking the green Code button > Download ZIP.
- Open the zip file, to unzip it into a folder.
- In Chrome, go to chrome://extensions (in the search/URL bar).
- Toggle on developer mode.
- Click on "Load unpacked extension".
- Open the unzipped folder.
- Turn off developer mode.
- All done! Open a new tab to start the Map Quizzer.
This repo contains the files for a Chrome extension that opens a map quiz every time a blank tab is opened in Chrome. The quiz pulls a random map from the online collections of the Library of Congress and asks you to guess which year the map was published. Three options are given: the correct publication year and two other years pulled randomly from the same corpus of maps.
The extension is built using Vue.js (a JavaScript framework) and Tify (a IIIF image viewer and zoomer, from the Göttingen State and University Library).
Map Quizzer selects from a pre-processed json-formatted list of maps online from Library of Congress at loc.gov/maps. The data was pulled using the loc.gov API, and maps were bias sampled with the following filters:
- Maps must be published to loc.gov via the Library of Congress catalog. This excludes maps from the Sanborn set.
- The publication year must be known (no question marks in the date field)
- Approximately 3/5 of English-only language maps were filtered out, to increase hetergeneity of data.
- Common publication years were thinned. Years with 100+ maps often represent homogenous map series or US Civil War maps.
The IIIF links pulled from the API were also altered to increase or decrease the image size to better fit the extension layout. For example, this IIIF url provided by the API would return an image 1052px wide, which is much wider than the extension needs:
Whereas this slightly altered URL returns the same image at only 673px wide:
Using Vue.js, the data is loaded directly from the background.js file.