As it turns out that even after my previous rant, I’m still trying to reason out UX patterns and their reasons on a daily basis. If you haven’t yet read the rant, you should — here you go.
So question for today, Why are timelines horizontal?
Sometime back, I started making an data driven interface which has a timeline as its central requirement. You go ahead in time to see the future predictions and back in time to see how off those prediction were. In the present with all of the live data, you get to take actions to make those predictions better for the next time.
This begs the question, what is ahead and back in time, or forward and backward in time. How have these been assimilated in our language?
Timelines have always been horizontal. The horizontal time axes in all graphs made in sciences, history, geography, reaffirms its lineage. Past time has been to the left and future to the right. Even when writing on an A4 size sheet in portrait mode, where things written above are in the past while below is the most recent writing, one would instinctively turn the page into landscape when asked to draw a timeline. There would be no infographic made with B.C. above and A.D. below in the vertical format.
The usage of vertical for time came with the mass adoption of the mobile phone which predominates in portrait mode. Even within such a vertical mode, the user’s mental model switchs from ‘up being the future/new’ — as used in feeds, while up being the past and down being the new/recent — as used in chatting applications.
Another analogy that comes to mind is that of walking. Walking into the future from the past. Thus making the place where one is standing as the most recent, which is down and at the user’s feet (hand in case of phones); and behind the user as the past and away from the user, in front of the eyes of the user as the future. This represents the feeds.
Since there are already conflicting mental models within the vertical representation of time so much so that it is almost magical that both of these conflicting user experience exist in some of the most successful companies simultaneously.
Another possible reason may be that the position of the keyboard towards the bottom of the screen. It helps to keep consistency and let things flow from the keyboard towards the bottom of the screen and the on screen information moving from the bottom to the top of the screen.
As one of my friends pointed out, any sequence building generally exhibits horizontal timeline. Such as music and video production has horizontal. It would be almost impossible to imagine a video editor with a vertical timeline. Whereas position in a group such as playlists, filters within tables, documents sorting is on a vertical timeline.
Adding to this, a horizontal widescreen desktop monitor reaffirms the usage of a horizontal timeline.
With all of this, I decided to go with a horizontal timeline. Left imply things that are now left out, and right imply the things that are right around the corner!
As goes always, these are my opinions and would love to hear out yours.