[IxDA Discuss] Graphical methods for displaying time elapsed

[Will Parker]

On Mar 2, 2007, at 11:47 AM, dnp607 wrote:
>> Can you provide a _good deal_ more detail on the application,
>> audience and functional goals?
>
> Thanks for the response Will. Frustratingly, no. I'm sure it would
> yield excellent results from this learned group to give more detail,
> but I'll have to settle for collecting different UI methods of
> displaying a few alarms in relation to time.

OK, I can understand that you might not be able to implement this  
advice, but I'll point out that a working IxD practitioner needs to  
learn the art of diplomatically pushing back when the client hasn't  
provided enough information to properly characterize the overarching  
goals of the project. If the client is insisting on a generic  
solution that could lead to a bad (and possibly dangerous) user  
experience, it's _your responsibility_ to find that out before the  
trouble starts.

>> You mention "many alarms" in several different classes over a 30-
>> minute session, and indicate that the user will probably be
>> required to simultaneously track both current alarms and past
>> alarms, using only a simple graphical display. That doesn't sound
>> like a pleasant user experience no matter what how you design the
>> data presentation, and quite possibly could lead to a large number
>> of user errors while using the application.
>
> I correct my statement about "many alarms", it is only 3 types (let's
> say "Good' 'Not so Good' and "Bad"). Your point about having users
> juggle current and past alarms, however, is most salient.

First, I would consider whether we could entirely eliminate the 'good  
alarms'. Do we really need to see a signal indicating that all is  
going well? "Hey, you're still breathing and have a pulse!!" Looking  
at it another way, can we reduce the complexity of the real-time  
presentation by using the implicit assumption that "no signal" ==  
"state is good"?

Using this model, the primary presentation could show only 'Bad' and  
'Worse' events in a timeline, with an option to also show the 'Good'  
events if the user switched modes.

Second, remember that you should never use only one sensory modality  
to convey important information. Color alone is not enough. For your  
event timeline, you _can_ use just color, because those events are  
now history. However, you're describing a situation in which the user  
must assess the _current_ level of 'badness'; therefore, you should  
also provide a strong, immediately distinguishable signal of the  
current state.

For most cultures, you can probably get away with yellow and red for  
'kinda bad' and 'really bad'. Add a shape and/or animation to enhance  
that - perhaps a triangle for 'kinda bad' and a square for 'really  
bad', with a flashing effect added to the latter. Be prepared to  
defend your choices for the current-state signal if the design is  
going to be used across a number of cultures. The localization  
process is a real pain if you're not careful.

> I'm researching different options for a graphical display of when an
> alarm occurs in relation to time, but it can be accompanied by text
> as well (such as a rolling log). The user needs to know two things:
> Which of three alarm states are occurring right now, and which have
> occurred within a 30 minute window.

I recommend three main elements:

- Current-state indicator, as described above, to guide immediate  
user response to correct for bad states. Always visible, and  
prominently placed in the UI layout.

- Scrolling timeline of the events of the past 30 minutes, displayed  
in 30 1-minute blocks; square or rectangular blocks would work. Add  
some sort of hashmarks to visually separate the timeline into 5- 
minute segments. If you can have two adjacent signals of the same  
level of severity, you'll need to indicate the boundaries between two  
adjacent events of the same category. Here I'd recommend a black line  
extending above and below the boundaries of the main timeline. You  
might also arrange this as a series of six 5-minute rows, with a  
clear indication of sequence, from newest to oldest.

- Some method of selecting a given event and thus revealing the  
important details of that event - for example, start time, duration,  
type of event, source of error (e.g, '1201: 1206 - Navigation error -  
Yaw rate > 12 degree/sec').

For an alternative method of dealing with a timeline of events, see  
the Google Finance method of calling out important events  in a  
timeline (Example: http://finance.google.com/finance?q=aapl). They  
add flag markers to high-importance events, with links to detailed  
reports (news stories). They also offer less detailed callouts of the  
data at any point in the timeline when the mouse is moved across the  
timeline itself (watch top right corner of chart area while mousing  
across chart). Not simple to implement, but doable, and worth the  
effort for understanding complex data displays.

>
> Ari, thank you for the pie chart suggestion, that's a good one.
>
> I've also seen time (again, progress related) represented as a
> circular graphic, such as when a Mac boots up.

Might be a bit hard to display/access all the events in a 30-minute  
pie chart if space is limited and/or the number of events is much  
above 20 AND the selection method is something other than keyboard  
commands. I don't have a link to the research, but I've seen a number  
of usability studies that show most people display less fine-motor  
accuracy moving a mouse cursor in a circle or arc than they do when  
moving a mouse in a horizontal or vertical line.

>
> Any other novel representations of time or an event in time?
>
> Regards,
> -Dan
>
> -------------------------------------------------------------
> Dan Peknik * NASA Ames Research Center
>         San Jose State University, ID HF/E
> -------------------------------------------------------------


- Will

Will Parker
wparker at ChannelingDesign.com
206-228-3187 (cell-preferred)
206-783-1943 (home office)


"The only people who value your specialist knowledge are the ones who  
already have it." - William Tozier