Page Previews

The Hovercards beta feature solves the core problem of users needing to open multiple tabs to gain an understanding of a word or concept within the context of the subject they are reading. With Hovercards, whenever a reader hovers over a link to another article, a short summary of the subject and an image (if available) is displayed. The user can then decide whether they wish to visit that subject more thoroughly before continuing with the current article. A complete description of hovercards functionality can be found here.

Introduction
Hovercards are designed to reduce the cost of exploration of a link, as well as to promote learning by allowing readers to gain context on the article they are reading or to define an unfamiliar term, object, event, or idea without navigating away from their original topic. For casual readers, Hovercards will make it easier for users to get an overview of an article before deciding whether or not to browse to it. Users interested in reading an entire article in its totality will not be distracted or discouraged by viewing unfamiliar concepts - they can simply preview the concept without navigating to a new page. Consequently, the smoothness of the user experience for these users will be increased.

There have been many requests over the years for a similar feature; there are browser extensions (see list) and one heavily used gadget (the more editor-focused Navigation popups) that also exist to solve this problem. Hovercards were first built as a beta feature in 2014 and have been among our most popular beta features in terms of adoption, user feedback and impact on usage. On the primary talk page for Hovercards, over the course of 2 years, numerous issues across all projects were identified and resolved. The mobile equivalent of Hovercards, implemented on the Android app in September, 2015, led to a 20% increase in links clicked per page.

The Hovercards settings panel enables logged-out users to enable and disable the feature based on their preferences. Logged-in users can currently enable and disable the feature from their beta settings. If Navigation popups and Hovercards are enabled at the same time (typically, for logged in users who have opted in via the beta feature), Navigation popups takes precedence. To enable Hovercards, Navigation pop-ups must be disabled.



Design
For the current iteration of Hovercards, each hovercard will contain the following:
 * A portion of the first paragraph from the article
 * An image (if available) from the article. Images will appear horizontal of vertical depending on the location of the link within the article.
 * A settings cog which will allow users to turn Hovercards on and off

Key differences to Navigation Popups

 * Navigation popups are for power users and has many features that are not relevant to most site users.
 * Hovercards is styled to enable easy reading. Currently, Navpop-ups' type-size is small and the margins are tight.
 * Hovercards will be available to all users, not just logged-in users
 * Create a consistent visual style with the article type treatment.
 * Emphasize the lead images, so a user gets an idea of a term using both text and image.
 * The action set in the gadget feels out of context, hence we need to validate which of those actions are useful for readers and editors.
 * Include the last edited timestamp that we have tested on Wikipedia mobile web.

Upcoming Name Change
Hovercards is the beta name for this feature. As this name contained potential usability issues (it doesn't make it clear what this feature actually does), upon graduating the feature to stable, Hovercards will be known as Page Previews. The name was derived during our qualitative tests by observing the names with which users naturally referred to the feature.

Logged Out Users
Logged out users may turn Hovercards off via the cog-icon displayed at the bottom of each hovercard. If a user wishes to re-enable Hovercards, they can be enabled via the "Enable Previews" link available at the bottom of any wikipage.

Logged-In Users
Currently, logged in users may enable or disable Hovercards from the beta features page. Upon promotion of the feature, logged-in users will be able to control their settings from two places - the settings cog and the user preferences page. There is currently agreement that logged in users should opt-in via their user preferences if they would like to use Hovercards.
 * If a user chooses to select the settings cog, the system will redirect them to the user preferences page.

Open/Close delay timing
Logged-in users can change the timing of how fast Hovercards appear and disappear (open/close delay). See Extension:Popups for instructions.

Success Metrics and Feature Evaluation
A number of qualitative and quantitative tests were performed to evaluate the performance of the Hovercards feature. These tests were focused on the following questions:
 * Do users enjoy Hovercards and find them useful?
 * How do Hovercards change reading behavior and do they help users be more accurate when selecting the articles they wish to read?
 * Would launching the Hovercards feature have effects on fundraising?

2015 Greek and Catalan Wikipedia test
A feature test on was implemented for a period of 4 months on Greek and Catalan Wikipedias. A number of issues and bugs were reported and user satisfaction was recorded using a survey. Users had generally favorable feedback, with the majority of users finding Hovercards useful, easy to use, and enjoyable to use.

Read the full results of these tests.

2016 Qualitative test
To determine user attitudes towards the Hovercards feature and trace further changes in reader behavior, an unmoderated remote panel study was performed using UserZoom software. The majority of participants reported positive attitudes to the Hovercards feature. In addition, the majority of participants had no issues in turning the feature on and off. Users also described the feature in generally positive terms and reported it was not distracting to their reading experience.

Read the full results and analysis of this test.

2016 A/B tests on Hungarian, Italian, and Russian Wikipedias
To determine changes in reading behavior and evaluate the success of the Hovercards beta feature, three A/B tests were launched on Hungarian, Italian, and Russian Wikipedias. The A/B test on Hungarian was launched June 7, 2016, the A/B tests on Italian and Russian were launched Sept 23, 2016.

From the results of these tests, we can conclude that Hovercards facilitate positive changes in reading behavior by increasing the precision with which users select the pages they read, reducing the cost of exploration of other pages, and allowing users to selectively focus on a single topic by providing context within a page.

Read the full results and analysis of these tests.

Future Iterations and Potential Improvements
Upon success of an initial launch of Hovercards, we are planning on iterating on the feature to add functionality. These items will include:
 * Configuration - a number of users have requested making images configurable within Hovercards. We're marking this feature for future implementation and tracking it in https://phabricator.wikimedia.org/T148995
 * Article titles - currently, only the summary of the article is available within Hovercards. As an iteration, we would like to display the title of each article along with its summary
 * Reference Tooltips (T67114)

FAQ
This is a feature intended to improve the experience for any reader who normally would have clicked on a blue-link in Wikipedia because they needed an overview (definition) of that entity.
 * Why Hovercards?

The theory of impact for Hovercards is that they lower the cost of exploring a link. This should mean that users are less inhibited and more focused when exploring links. We should see that the overall links clicked + (non-accidental) hovers exceed the number of links clicked without Hovercards. This is what success looks like. There are also some indications of failure that we will look for: If you have Navpops enabled, Hovercards are automatically disabled. You will have to disable Navpops in order to experience Hovercards. This is an intentional decision to ensure that Navpop users' do not have their preferences interrupted. Note: for certain browsers, you might have to clear your browser cache first for the change to take place. Right now, Hovercards will either be turned on or off by a user. The option to turn them off lives in each hover event. So at each hover event, a user can decide that they are no longer interested. For logged-in users, Hovercards may be re-enabled from user settings. For logged-out users, Hovercards may be enabled by selecting the "Enable Previews" link at the bottom of the page.
 * How do we measure Hovercards performance?
 * hovers can be accidental-we need to measure normal dwell time in a controlled condition to ensure that the likely rate of accidental hovers is not too high. To give an example, if a user must dwell on a link for 250 msecs before a hover shows, then we would want to make sure that there are not a large number of users who tend to dwell on a link for more than 250 msecs without clicking it.
 * Hovercards could lead to fewer pageviews, because the user gets the information that they need from the preview- this is not a problem, but we want to make sure that the decrease (if any) does not result in significantly less editing or fundraising.
 * the % of hovers that result in a user continuing to the page is high - this would suggest that most people wanted to go to the page anyway. If this is the case, then the hover is likely just adding an unnecessary step. We expect some significant % of click throughs for hovers. It is ~60% on Android for a similar feature, but we expect it to be lower on desktop.
 * the percentage of users who disable Hovercards is low (given that users are aware on how to disable the feature) - this suggests that users enjoy the feature
 * What if I have Navpops enabled by default?
 * How many options do I have in Hovercards preferences?

At the project level, administrators can determine how long a user should dwell on a link before a hover is triggered. If a project wants to be conservative, the lag can be longer. WMF will have a recommendation as to optimum dwell time that provides the best user experience while minimizing accidental hovers. Unfortunately, there is no good way to tell users about a new feature without showing it to them first. Central notice banners have been suggested, but running them for 2 weeks would not solve the needs of future users and we do not want to run them continuously. Notifying a user of a new feature is best done using a...hover-over. So that is why we are planning to show an initial hover on the users first hover event, followed by an explanation of what the user has seen. They can choose to turn them off in that dialogue. Please go to the Hovercards discussion page, here: Talk:Beta Features/Hovercards
 * Why can't users just turn on Hovercards if they want them?
 * Why can't users just turn on Hovercards if they want them?
 * If I have Hovercards feedback or if I have a suggestion for making them better, where should I go?
 * If I have Hovercards feedback or if I have a suggestion for making them better, where should I go?

Code

 * Analytics and instrumentation
 * Hovercards are currently instrumented to measure various aspects of usage. Please see the popups extension page for details and feel free to ask any clarifying questions.

Rollout Plan
We would like to begin rolling out to Greek and Catalan Wikipedias, as those users represented highly favorable views of the feature. After this, we would like to continue rolling out in stages to other projects:

Onboarding Experience
The onboarding experience for the feature will depend on the consensus of each community on having Hovercards on by default or providing users with an onboarding experience during which they can reject the feature. The discussion has began on English Wikipedia with no current consensus. More info here: https://en.Wikipedia.org/wiki/Wikipedia:Village_pump_(proposals)/Archive_131#Proposal:_Enable_Hovercards_by_default