Reading/Web/Desktop Improvements/Features/Collapsible sidebar

We would like to give readers and editors the flexibility to collapse and uncollapse the left menu (the sidebar>Sidebar|sidebar) so that a more focused view of the content, as well as the most important functionality, can be available when needed.

By this functionality, we would like to pursue two of the main goals of our project. First, we would like to make it easier for people to focus on the content itself, whether during reading or editing. The other of these goals is to highlight important functionality such as the edit and history buttons, language switching, and search.

Release plan
We began deploying the first iteration in May 2020 to Office Wiki and Test Wiki, and plan to continue to our early>Special:MyLanguage/Reading/Web/Desktop_Improvements#List_of_early_adopter_wikis_(test_wikis)|early adopter wikis in following months. See our features>Special:MyLanguage/Reading/Web/Desktop Improvements/Features|main Features page for more details.

Feature description and requirements
The collapsible sidebar feature will introduce a button in the top left corner of the screen. Selecting this button will collapse the sidebar and hide the items within it. To open - press the button again.

If logged-in, your sidebar collapsing preference will be saved. This means that if you chose to have the sidebar collapsed, and then end your session, your sidebar will still be collapsed when you start a new session, and vice-versa.

For logged-out users, the preference will only be saved within a given browser window.

Design requirements and guidelines
We have prepared a [https://di-collapsible-sidebar-5.firebaseapp.com/Hathor  prototype of this functionality].

Constraints
Currently, a few projects (such as Korean Wikipedia) already implement similar behavior by default. We would like to work closely with the communities of these wikis to ensure there are no bugs or other issues with sidebar collapsing.

If your wikis are currently using a gadget for collapsing the sidebar, please contact us.

With editors
We performed a feedback round with a prototype of the collapsible sidebar with editors across multiple wikis. Editors were invited to explore the prototype and provide their feedback using a central notice banner. The majority of users who provided feedback liked the collapsed sidebar for personal use, and especially for the purposes of reading. Please read through our report>Special:MyLanguage/Reading/Web/Desktop Improvements/First Prototype Feedback Report|report for more details on feedback, concerns raised, and iterations.

With readers
A prototype of the sidebar was also tested with readers through a user study done in collaboration with an independent user testing firm, Hureo, based in India. During the course of the study, we studied readers unfamiliar with Wikimedia projects, as well as casual readers who use Wikimedia projects regularly. The tests were performed in English, Hindi, Telugu, Tamil and Marathi.

Readers reported a strong preference towards the collapsed version of the menu, stating that it created a better reading experience than the current version.

We will be publishing the full results of this study soon.

Quantitative testing
Once deployed, we are planning a series of quantitative tests on the collapsible sidebar which will help us determine the success or failure of the feature. In particular, we will be focusing on the following questions:


 * Does introducing a collapsible sidebar lead to a significant increase to sidebar links?
 * In what ways is the sidebar used? Do people have it open or closed for the majority of the time?