The general GUI principle "don't off something that isn't available" shouldn't be used if it creates "can you figure out why this isn't available?" I was part of the team that created the first principle and I have watched people struggle with its result "can you figure out why...", as have I, during the intervening 25+ years. ;-)
There is always a trade-off between explicit information, effective use of the available screen space, and visual clutter. The latter two raise considerable usability issues of its own when we try to force too much into too little space. We need to design for the primary task. Remember that the user very likely already has a specific disk in mind for the install and will look for and select that disk directly, ignoring the others, so we want to make locating a specific disk as easy as possible even if it isn't usable. If we knew in advance which disk he is looking for we wouldn't even show the others. :-) The emblem tells the user that the disk isn't usable. The high-order bit of information is immediately visible. The message, definitely the second-order bit, is visible only when selected thus reducing visual clutter and saving screen space that can be used for more high-order information. We don't show the message on roll-over as that action already provides additional information about the disk, e.g. disk manufacturer and perhaps controller info, to enable the user might use to more accurately identify the actual disk. Combining both identification and error information creates a confusing situation and forces the user to mentally separate the two messages. The warning triangle will be used in cases where the disk is usable but there might be some sort of issue of limitation in its use. Not sure what these might be yet, but expect that they will arise. Frank Michael Pogue wrote: > Yes -- I like that idea as well. It addresses the general GUI > principle "don't offer something that isn't available" (also known as > "Want this? Can't have it.") :-) > > If the circle with a line through it is still not enough info, we > could alternately overlay a yellow warning triangle and some text "too > small for installation", or "not enough space", etc...that would both > make it not selectable, and make it clear why it wasn't available for > selection (before it was clicked on). > > Mike > > Shawn Walker wrote: >> On 06/04/07, William D. Hathaway <william.hathaway at versatile.com> wrote: >>> If disks that are too small (or otherwise invalid choices) can't be >>> "unselectable" can the icons for them be different at least (like a >>> hard disk image behind a "circle with a line through it") than the >>> legal disks? If I have 10 disks, but 9 are too small to install on, >>> it seems tedious to make the user select all 10 one by one before >>> finding the disk that it is legal to install on. >>> >> >> The different icon seems like a great compromise, that way people can >> still select the disk in question to find out specifically why it >> can't be used. >> >>> I'm not sure what ordering the disks are displayed in, but I'd also >>> recommend making the first usable disk be in the position that users >>> would be most likely select (the disk on the far left or top >>> depending on how the layout goes). >>> >> >> That also seems helpful. >> > _______________________________________________ > install-discuss mailing list > install-discuss at opensolaris.org > http://opensolaris.org/mailman/listinfo/install-discuss
