User interface paradigms that need changing? - windows

Often times convention is one of the most important design consideration for user interface. Usually the advice goes to do it like Microsoft does.
This is for three reasons:
If it ain't broke, don't fix it.
If your users expect to click on a floppy disk icon to save, don't change the icon (even though some of them may have never seen an actual floppy disk).
Users don't want to re-learn the interface (and hot keys, etc.) with each different application they use.
At the same time Emmerson said "*A foolish consistency is the hobgoblin of little minds.*" So when does maintaining a consistent user interface cross the line from a good idea to stagnated innovation?
Microsoft shook up the good old WIMP GUI with the introduction of the tool bar, and then again with the Ribbon control (which is the natural evolution of the tool bar, like it or not.) Now we are seeing ribbons everywhere.
So my question is, what are some user interface paradigms that are accepted and consistent across multiple applications, but have stayed past their prime and are starting to reek? Are there some important changes that would benefit from a grass roots push by developers to innovate and improve the user interface experience for our users?
One thought that came to mind for me is the modal pop-up dialog. You know the ones that say: "Are you sure you want to . . .. - [Yes] [No] [Cancel] [Maybe]" and its evil twin "Successfully completed what you wanted to do! [OK]." We are seeing a movement away from these with the "info panel" in browsers. I think they need to be adopted in windows application development as well.
If possible please list a solution for each stale UI item.
And please don't list clippy. We all know he was a bad idea.
NOTE: This is specifically Windows client user interface paradigms, but I am certainly open to drawing inspiration from the web, the Mac, etc.

You mentioned popup modal dialogs , and I'd argue that non-modal ones are just as bad. Any dialog box remove focus from the program, they could end up behind the program and make it hard to find it, they might not even appear on the same virtual screen.
I'd like to see an end to all dialog boxes. If you need to stop someone from using the UI because of some non-normal circumstance, then remove the relevant parts of the UI from the window, and replace it with what the dialog would contain. Bring back the UI once the problem has been handled.

Clicking things on touch interfaces
It's incredibly difficult to click on things on a touch interface, because you don't know when you have pressed the screen hard enough. And if you add an animation to the button you are clicking, you most likely wont see it, because your finger is in the way. Adding other reactions, like vibrating the phone or painting waves on the screen might work, but there is usually a delay which is too large, much larger than the tactile sense of a button being pressed. So until they invent a screen with buttons that can be pressed, all touch devices should move towards dragging user interfaces (DUIs) instead.
Counter intuitively it is easier to press an object on the screen, drag it, and then release it than it is to just press and release it. It's probably because you can see the object moving when you start dragging, and you can adjust the pressure while dragging it. Dragging also has a lot more options, because you now have a direction, not just a point that you clicked. You can do different things if the user drags the object in different directions. Speed might also be used, as well as the point where the user releases the object. The release point is the real strength of DUIs, because it is very easy to release something, even with pixel precession.
Some designs have started to use DUIs, like (here we go) the iPhone, palm pre and android phones. But only part of their design is DUI, the rest is clicking. One area they all have in common is the keyboard. Instead of clicking on a key the user presses any key, then drags their finger towards the key they really wanted to click. Unlocking these phones also uses dragging.
Other easily implemented DUI features would be things like mouse gestures, where dragging in different directions, or drawing different shapes does different things. There are also alternate keyboards being researched which puts a bigger emphasis on dragging. All buttons can be changed into switches, so have to drag them down a bit to click them. With a well designed graphics, this should be intuitive to the user as well.

The Apple Human Interface Guidelines are a good read on this topic. They discuss this from a very broad point of view and the guidelines apply to any platform, not only Mac.

The file system. I want to save a file.. >OOOPs I need to think of a file name first. Well.... how about ... blah.doc.
6 months later...
Where the %#*(%& * did I save that %()#*()*ing file?
The solution is build a versioning system into the application, or better, the OS. Make files findable by their content, with a search engine, instead of forcing the user to come up with a memorable name, when all they want is for their file to not get lost.
Eliminate the save step. Type something in to the application, and it's just there, and there's no risk of losing it by some misstep, like forgetting to save. If you want an older version, you can just pick a date and see what the document looked like back then.
To build on the search engine idea: It's a pain having to navigate some arbitrary tree structure to find your stuff. Searching is much easier. However, you might still want to have something like a "folder" to group multiple files together. Well, you can build a richer metadata system, and have a "category" or "project" field, and setup the search engine to show items by project, or by category. Or group by those, or whatever new UI discovery we make next.

This question is a bit too open-ended, IMHO.
However, my main approach when designing anything is:
Fits in to wherever it is. If it's a windows app, I copy MS as much as a possible
It's simple.
It provides options
Buttons have a nice description of what the result of clicking will be, as opposed to 'yes or 'no'
Harder to answer the rest of your post without spending hours typing out an arguably useless (and repeated) set of guidelines.

In my mind, the one thing that really stands out is that USERS need more and easier control over the application's user interface appearance and organization.
So many interfaces can not be modified by the user so that the most used/favorite functions can be grouped together. This ability would make your favorite software even easier for you to get things done.

Error messages need a "Just do it!" button.
Seriously, I really don't care about your stupid error message, just DO WHAT I TOLD YOU TO DO!!!

I think the entire Document model of the web needs to change. It's not a user interface, but it leads to many, many bad user interfaces.
The document model was a good idea to connect a bunch of documents, but now the web is also a collection of applications. Today, I think the Page/document model corrupts our thinking. We end up lumping things together that aren't related, modularizing our code wrong, and in the end confusing users with our monolithic control board type websites.

Find dialogs that sit over the widget in which you are doing the search are terrible. Loads of apps do that. The find bar in Firefox works much better.

Many applications have multiple panes within the UI - eg in Outlook there's the preview pane and the inbox pane (amongst others). In these applications typically cursor key presses apply to the currently focussed pane. But there's very poor hinting to show the user which pane has focus and there are seldom keyboard shortcuts to move the focus between panes.
The focussed pane should be highlighted somehow.
Something like alt+cursor keys should move the focus around.

Ctrl-Tab and Ctrl-Shift-Tab cycle left and right through tabs instead of MRU behavior, even though in most cases the same behavior is duplicated with Ctrl-PageUp and Ctrl-PageDown.

There are a lot but here's an idea for a couple of them:
Remove some clicks like in "add another" or "search item" and the like.
This is well done with interfaces like ajax which have autocompletes ( and auto search ) but is slowly being adopted for platform UI's ( and in some cases they were originated in platform UI's. )
This is how StackOverflow does it for some scenarios.
But of course, we all know that already don't we? No need for "Seach tag" or "Add another tag" buttons, they just happen
Dialogs as you described.
Guys at Humanized proposed Transparent messages which actually are used in their product Enso and some other places.
Mac uses them for notifications ( like in Growl ) use them very well, or Ubuntu new notification system.
alt text http://blogs.sun.com/plamere/resource/NowPlayingGrowl.png
Firefox replaces the traditional "Search" dialog box with a search bar at the bottom.
Although not everyone likes the placement for next/previous as in this screenshot
And even SO ( again ) :) replace the notification with the yellow bar.
Finally:
File managers
I really like ( sometimes ) the simplicity of regular file managers, but some times I would like to work faster/better with them.
If you compare IE 4 with IE 8 you can tell the advance ( even better compare IE 4 with Google Chrome )
But if you compare Windows 95 Explorer with Win XP they are almost the same!! ( Win Vista/7 is a step forward )
But I wonder: Why haven't file managers improved as much as webbrowsers?
That's one reason I like stuff like QuickSilver but it is just a step. Much work is needed to create something like a "Perfect program launcher" or (FileManager/DesktopSearcher etc as you wish )
QuickSilver featuring "move to" action

Related

Name of window from tray

I have a rather unusual question, namely, how is called this window from icon tray?
I would like to make it in my application, and I could not find his name. I would ask for some information, or the name, the rest I should have to deal with.
The Windows UX Guidelines don't say anything about it. From my perspective it's just a normal dialog, albeit one that has rather immediate actions (as opposed to first clicking on an OK button of sorts) and resides in a fairly small size in a specific location. It is meant to be opened, interacted with quickly and then dismissed, never being the center of your attention. If your idea fits those criteria as well, then go ahead. It's easy to recreate with standard means.

Are Keyboard shortcuts mandatory for 508 compliance

I researched a lot on this and seem to be getting conflicting answers on SO and all of the web. I understand that with Section 508 that compliance DOES NOT equal accessibility.
Biggest thing is that the UI/UX designer is being told that keyboard shortcuts for the dropdown menu NEEDS to have keyboard shortcuts to be 508 compliant. I see Windows Forms applications having this, but for web development I do not think that is mandatory to be "compliant"
My other question that was answered is here: MVC 4 site 508 compliant
I partially agree with thinice, but agree with the first two sentences of the comment left.
The sentences I am referring to are:
They should be -reachable- by keyboard for 508. I'm maintaining emphasis on the difference between a shortcut and being reachable
Crixus said:
Biggest thing is that the UI/UX designer is being told that keyboard shortcuts for the dropdown menu NEEDS to have keyboard shortcuts to be 508 compliant.
You need to clarify this. Do you mean a simple <select> or a drop down for a navigation menu? As Thinice stated in comments, Section 508 just says needs to be reachable. The question becomes:
how are you adding shortcut keys to your application? Are you adding them via the accesskeys attribute or how Gmail/Yahoo Mail adds shortcut keys?
I thought I did an answer about AccessKeys, but cannot find it. Essentially accesskeys sounds like a great thing, but if you look at the keys you are allowed to use that do not interfere with either browser or Assistive Technology keys, you are quite limited. Gez Lemon did an overview of AccessKeys, and their issues. If you want to do the Yahoo!Mail approach, you have to do a bit more work. Todd Kloots made a presentation about ARIA, which may be helpful. Which leads me into the second part. If you are using JavaScript heavily on a site to do stuff, people use both 1194.21 (software application/OS) and 1194.22 (web) standards to evaluate a site. If the site uses JS to make a navmenu (YUI menu example), the drop down behavior needs to be reachable by keyboard. I would say this falls under:
§ 1194.21 Software applications and operating systems.
(a) When software is designed to run on a system that has a keyboard, product functions shall be executable from a keyboard where the function itself or the result of performing a function can be discerned textually.
AND
(c) A well-defined on-screen indication of the current focus shall be provided that moves among interactive interface elements as the input focus changes. The focus shall be programmatically exposed so that assistive technology can track focus and focus changes.
I say both standards are used because (a) says you have to be able to get into the navigation area via the keyboard. (c) comes into play because some menus you can tab to all of the parent items, but you cannot get into the drop down part without a mouse. I have seen menus that you can tab to the sub-menu items, but the menu does not pop open. So if you just use the keyboard (mobility imparments), versus using JAWS, you will have no idea where you are.
I see Windows Forms applications having this, but for web development I do not think that is mandatory to be "compliant"
I would say actual applications, like Word, Outlook, etc., supply shortcuts to frequently used commands. If you are doing this for a web application, I would think about how many you do. This is not a mandatory piece to be compliant. If you are making like a navigation bar, I would recommend using ARIA roles, specifically role="navigation", on the parent element as a best practise.
The problem with some standards (as well as many laws) are that they're open to interpretation...
The only mention I can find in the 508 standards that mentions keyboard use is this (verbatim):
Subpart B -- Technical Standards
§ 1194.21 Software applications and operating systems.
(a) When software is designed to run on a system that has a keyboard, product functions shall be executable from a keyboard where
the function itself or the result of performing a function can be
discerned textually.
My spin on this is:
A keyboard shortcut for navigation options may be impractical given the amount of operations/features a given section may contain. It is important that they're reachable -somehow- via keyboard.
From a UX standpoint, key features should have shortcuts "just because" it's good UX practice. But to shortcut everything goes from one ditch into the other.
508 != accessibility, but if you work for a gov/edu, chances are it's in your PD to be compliant.
Another end of the spectrum is the WCAG which is pretty much coupled with 508 compliance, and in my book better defined: Keyboard stuff is under 'operable' in WCAG.
In a nutshell:
It's good practice for UX to have custom keyboard shortcuts for important features. But has no bearing on 508 compliance by itself. (With exception that functionality should be reachable by keyboard -somehow-).
There are levels of 508 compliance, if you're talking about a government project. Some departments assign 508 scores to their developers, and it factors into your score for future contracts. 508 Compliance only requires that everything is reachable by keyboard, which is usually true, in a way. Screen readers will read everything that's not hidden, and tab keys will take people through links. But if you want a good score, you must address the intent and not only the letter of the law.
Edit: Screen readers will read some hidden elements. One method is to absolutely position an item above the screen with a negative top position. Another is to use the clip property.
http://adaptivethemes.com/using-css-clip-as-an-accessible-method-of-hiding-content/
But if you're using display:none, heights of zero, and javascript toggles, many screen readers will not speak these items.
In the case of a drop-down, you are actively hiding elements from screen readers etc, so you do have to fix it, because most readers won't hear things with display:none.
You will not find definitive documentation on keyboard navigation. The reason no one will specify exactly what to do, is that there are so many potential conflicts - with the browser, the OS, etc. There are also no standards, although Aria is making progress:
http://www.w3.org/TR/wai-aria-practices/#keyboard
I would not put accessKeys on a menu, if that's what you meant.
Instead see: http://www.w3.org/TR/wai-aria-practices/#aria_ex_widget
I would save actual accessKeys for major things like 'Search' and 'Home'. Adding a learning curve to your site wouldn't help the cause, if you had an accessKey for everything. If you put for example, "About Us" accessKey=A, and you had 20 accessKeys assigned to letters, it would be bad.
I've been doing 508 sites for a long time, and personally, I just don't use drop-downs. It's far simpler to add subpage menus. And I personally hate clicking on dropdowns. Dropdowns require a precision in clicking that just irritates me, and doesn't help with accessibility, because remember accessibility also includes people who don't click very well. Plus, dropdowns are limited in the number of levels you can have, not technically but from a UX view.
What I use:
Tab indexes.
Carefully placed menus so that a user won't get a huge list of links before hearing the basic idea of the site or page.
On some projects, tree menus with matching arrow-key page navigation, sequentially.
Accesskeys H for home and S for search, if needed.
The problem especially is in sorting information. Think how quickly you scan a long list of links, and then imagine sitting there and waiting for it to be read to you. Perhaps, organize your content into digestible pieces & let the search box do the scanning. Depends on the content.
Luck. :)

How can I simplify my toolbar interface as the list of commands grows? [closed]

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I'm writing an internal-tools webapp; one of the central pages in this tool has a whole bunch of related commands the user can execute by clicking one of a number of buttons on the page, like this:
toolbar http://img709.imageshack.us/img709/1928/commands.png
Ideally, all of the buttons would fit on one line. Ordinarily I'd do this by changing each widget from a button with a (sometimes long) text label to a simple, compact icon - e.g.
button labelled "Save" http://img337.imageshack.us/img337/773/saver.png
could be replaced by a familiar disk icon:
Unfortunately, I don't think I can do this for every button on this particular page. Some of the command buttons just don't have good visual analogs - "VDS List". Or, if I needed to add another button in the future for some other kind of list, I'd need two icons that both communicate "list-ness" and which list. So, I'm still considering this option, but I don't love it.
So it's come time for me to add yet another button to this section (don't you love internal tools?). There's not enough room on that single line to fit the new button. Aside from the icon solution I already mentioned, what would be a good* way to simplify/declutter/reduce or otherwise improve this UI?
*As per Jakob Nielsen's article, I'd like to think that a dropdown menu is not the solution.
Edit: I'm not looking for input about the icon idea. I'm looking for other solutions. Sorry my example disk icon was a small one; it was just an example. I'm showing a bigger one now to hopefully be more clear.
I would add a More Link Like Google does.
See the Top Bar of Google with WeB Images Map More >>
To this more >> drop down you can add logic to add button less frequently used by user or something like that.
If you read Jef (and Aza) Raskin, you'll probably realize that icons are also not a good solution – both were pretty vocal in their dislike for them (with very few notable exceptions). For a start they're even harder to hit than tiny buttons, then their symbols can be confusing, culture-dependent and misleading. We're already good at reading text, parsing and interpreting icons is often slower.
In any case, that button bar looks like it accommodates pretty much anyone and their dog who might be using that product. You might have had some specific scenarios in mind when creating it that should be easy to do and are important. Most likely not all buttons are needed at once for such a task to complete.
Another thing is that maybe not all buttons are even useful at any single state of the application. Can you maybe branch into different sets of buttons, depending on the state. That's only possible however, if each state has clearly defined what actions can be taken. If all buttons are equally pressable regardless of state this won't do anything.
Grouping commands according to related functionality might also be an option. This doesn't have to be done with menu-like idioms, you can also put them into containers with different background color or even color the buttons themselves (just keep in mind color blindness, though). Depending on how related those individual functions are this can be a good way of speeding up interaction. It might requier some training for users to know what the colors refer to but for an in-house tool that's only used by people you know (instead of by arbitrary random ones [which is a problem Microsoft faces quite prominently]) this should pose not much of a problem.
What if you use icons and text?
For the commonly understood commands - use just an icon (like the save)
For the uncommon commands use an Icon + the text.
If you put a border around the button as a whole it should tie the icons / text together nicely and show it's still a button. You could also do some hover effects.
Since you can't do a dropdown menu (or similar techniques like clicking a button to generate a secondary menu). The best I can think of is what Prescott did or showing an area of buttons that are grouped in such a way to make it easy for the user to know which section their button should be in.
I would start by changing some of the longer labels. At a minimum, "Application Loading" could be abbreviated "App Loading." What's another (shorter) way to say "Quick File Transfer"?
You could also group the buttons into tabs (i.e. make it a ribbon). That might work particularly well if different classes of users tend to use different, non-overlapping sets of buttons.
Numerous options:
Group and labeling. Any time you have more than eight commands, you should divide the menu items into semantic groups of about four to help the user scan for the command they want. Labeling the groups also helps the scan and can make the menu more compact. For example, Instead of VDS Ping and VDS List, Have a group labeled “VDS” with “Ping” and “List” menu items. You’ve one less word to fit in (two if you put the label above it’s associated menu items when using a horizontal orientation).
Pulldown menus. Nielsen is correct about avoiding the use of a dropdown menu for making commands. However, he’s clearly in favor of pulldown menus which look and behave like a menubar in a thick client app (Nielsen calls them “command” and “navigation” menus). I think you’ll find that there are several Javascript pulldown menus out there now, unlike back in 2000 when Nielsen wrote his post. You can fit 100s of commands in a menubar.
Sidebar menu. Arraying the menu items vertically and you should be able to fit 20 or more commands and you won’t have to shorten any command names to something user might not understand. If that’s not enough, consider a “menu bank” than combines the benefits of sidebar menu with the capacity of a pulldown menu.
Ribbon. If your commands fit into discrete tasks, where the user tends to stick to one task for a while, you can arrange the buttons on a tab control, with one sheet per task.
Command Overloading. Represent your data objects as selectable entities in your window and change your commands into more general operations, like Drill-down, Create, Copy, Move, Delete, and Link, that can be applied to various different classes of objects, thereby reducing your total number of commands. The user can select one or more data objects then select the desired command to act on them.
Work Area Attributes. Some of your commands may not be commands by settings or attributes. Remove them from the menu and represent them as data objects in the work area of the page (or another page, if they are rarely used) using controls like radio buttons, dropdown lists, and check boxes. This has the added benefit clearly showing the user the current setting as well as providing a means to change it.
Variants. For an internal app, you probably have formal roles and responsibilities that vary by work position. Include the user’s position in your model, and dynamically hide commands (and other controls and pages) that aren't relevant to that position.
What about a combobox and a Confirm button?
Or a simple dropdown menu?
Add a "Tools" or "Actions" menu bar, and stick rightmost 4 commands (or more) into the menu.
Would it be possible to implement a "most used" or "preferred" set of buttons (preferably for the user, but globally if necessary) and button to take you to the rest of the items if you need one of those?
You could group them (like the two 'vds' buttons) behind a single button that, when clicked pops a context menu with the individual icons.
It truly seems like what you're developing is a administration console which happens to present its UI through a web page, rather than something which I'd quantify as a web app. As such, especially given your statement that this is an internal use application, Jakob Nielson's advice regarding <select> tags being poor design need not apply.
For this particular set of assumptions, I think the better option is to imitate a system menu setup using one of the many CSS-based menuing designs possible.
Icons are terrible from a user experience stand point. A picture of a Floppy Disk doesn't un-equivocally mean SAVE. It means something to do with a Floppy Disk. A Floppy really, its 2010, SAVE on a web app means save to the server, how does a Floppy Disk even compute?
Here is an application that has had the same extremely usable interface for 10 years! And hardly any images for buttons, and it is one of the most productive applications in its category.
You know what ICONS stand for I ncomprehesible C ryptic O bfucsated N onsense S ymbol!
Also how do you internationalize an icon?

Where does the delete control go in my Cocoa user interface?

I have a Cocoa application managing a collection of objects. The collection is presented in an NSCollectionView, with a "new object" button nearby so users can add to the collection. Of course, I know that having a "delete object" button next to that button would be dangerous, because people might accidentally knock it when they mean to create something. I don't like having "are you sure you want to..." dialogues, so I dispensed with the "delete object". There's a menu item under Edit for removing an object, and you can hit Cmd-backspace to do the same. The app supports undoing delete actions.
Now I'm getting support emails ranging from "does it have to be so hard to delete things" to "why can't I delete objects?". That suggests I've made it a bit too hard, so what's the happy middle ground? I see applications from Apple that do it my way, or with the add/remove buttons next to each other, but I hate that latter option. Is there another good (and preferably common) convention for delete controls? I thought about an action menu but I don't think I have any other actions that would go in it, rendering the menu a bit thin.
Update I should also point out that delete should be an infrequent option - the app is in beta so users are trying out everything. This is a music practise journal, so creating new things to practise happens every so often (and is definitely needed when you start out using the app), but deleting them is not so frequent.
Drew's remark is always your first consideration. All other things being equal, I'm not a fan of making deletion as easy as creation; it's a dangerous and comparatively rarer action, and the UI should reflect that fact. However, not having an explicit delete control can indeed lead to support enquiries (the same happened in MoneyWell after the minus buttons were removed). The issue is that you won't hear from the people who avoided accidental deletion by hitting a too-close-to-the-plus deletion control; those people are happy and quiet. You will, however, hear from those who can't immediately find a button to click for deletion, even though almost all of Apple's applications have no such control.
If you feel that you need explicit UI for deletion, I think you can find a middle ground. The problem with deletion controls is accidental triggering, and the conventional "solution" to that problem is a confirmation alert. The problem with that is how intrusive and jarring they are, because they're modal. iPhone OS can teach us a lesson here: you can make confirmation entirely contextual and non-modal.
Examples are row-deletion (swipe to put the row into its "are you really sure you want to delete?" state, which visually tends to slide a red Delete button into view), then interact again (by tapping Delete) to actually confirm the action. There's a similar model on the App Store whereby tapping the price button changes it into a Purchase button; it's essentially an inline, non-modal confirmation. The benefit is that if you tap anywhere else (or perhaps wait a while), the control returns to its normal state on its own - you don't need to explicitly dismiss it before continuing work.
Perhaps that sort of approach (non-modal change as a sort of inline confirmation) can get rid of the support queries by making deletion controls explicit, but also patch up some of your reasonable concerns about intrusive confirmation.
I would say this depends on how important deletion is to the particular task. Is it something that the user has to do often, or very rarely. If it is rare, delete should just be left as an Edit menu option, and perhaps as backspace (Why cmd-backspace? If you can just have backspace, you probably won't get as many queries.)
As with everything in interface design, my take is to apply an 80-20 rule. If something belongs to the 20% of most used functionality, it should be exposed directly in the interface. If it is in the other 80%, you can hide it deeper (eg in a menu, action menu etc).
A + button is definitely in the top 20% --- you can't do anything without it --- whereas a delete is usually not a common operation, and is destructive, so can probably better be hidden away a bit.
The usual solution to this problem is to put the [+] and [-] buttons next to each other (see, for example, the Network pane in System Preferences). I generally find those buttons large enough that I don't hit the wrong one by mistake, although I can see that potentially being a problem.
If that option doesn't suit you, maybe take inspiration from Safari: put an 'x' inside the selected (or hovered) item.
Since your app supports undoing of deletion, I would suggest that you err on the side of making deleting stuff easy (at the expense of making it too easy) and make it obvious that these mistakes are easily undo-able. GMail does a decent job of that.
HTH.
How frequently is delete needed? Does the data and the user's expectation encourage deleting this data often? (is it a list of tasks, for example)? If so i'd certainly include a contextual action menu, even if Delete was the only option.
Cmd + Backspace may be a little unusual for people too - I know it's used in other places on OSX, but those places also provide context menus to expose the delete - i'd be surprised is every user knows about Cmd + Backspace, so i'd probably change it to Backspace (you do have undo support, so you're covered there).
Finally, and hopefully I don't sound like a git, but it suggests that the built-in help doesn't offer enough guidance on this - might be worth revising it?
Matt gave pretty much the same answer I was going to write.
Note that when you delete the object, you should animate it away: this provides valuable visual feedback: the animation (about 1/3 of a second is good) is long enough to catch the user’s eye, and they’ll see the object disappearing. If the object just disappeared without animating, the user would notice that something had changed instantaneously in the list, but would be less certain what it was. The animation reinforces the meaning of the delete button in the user’s mental model.

Know any unobstrusive, simple GUI guidelines or design recommendations for notifications?

I'm in the process of designing and testing various ideas for an application whose main functionality will be to notify users of occurring events and offer them with a choice of actions for each.
The standard choice would be to create a queue of events showing a popup in the taskbar with the events and actions, but I want this tool to be the less intrusive and disrupting as possible.
What I'm after is a good book or papers on studies of how to maximize user productivity in these intrinsically disruptive scenarios (in other words, how to achieve the perfect degree of annoying-ness, not too much, not too little).
The user is supposedly interested in these events, they subscribe to them and can choose the actions to perform on each.
I prefer books and papers, but the usual StackOverflow wisdom is appreciated as well.
I'm after things like:
Don't use popups, use instead X
Show popups at most 3 seconds
Show them in the left corner
Use color X because it improves readability and disrupts less
That is, cognitive aspects of GUI design that would help users in such a scenario.
For notification, I prefer small notification windows in the bottom right corner. If they have a minimum UI allowing me to take some quick action, it would be ideal.
As model: incoming mail notification from Outlook, Skype notifications for incomming calls, etc.
I have read and recommend:
About Face 3
The Design of Everyday Things
I don't know of any formal articles but the Ubuntu UI design team have considered this issue and you may find something of value in their notification design guidelines or in this discussion by Mark Shuttleworth.
Sorry, no book recommendation here, just one piece of advise: Ultimately, you should let your users decide.
In my experience, what one user considers to be a useful feature is seen as completely broken by the second, while the third doesn't care at all.
Offer them 3-5 options how they will be alerted (including the option to turn alerts off ;-). Of course you should optimise these options as much as possible, hopefully some other answers here can help you with that.
A collection of possibilities:
Change a static tray icon. Useful if the user doesn't have to answer each message immediately, and relatively unobtrusive. Should be an overlay on the original image, making sure that the user recognizes which application it's from, and should be different enough that the user immediately understands that it's not the original icon (for example, a red / yellow exclamation mark on a blue / green background).
Change the tray icon to a dynamic variant. This will be more obtrusive, grabbing the user attention periodically, but is useful when the message is urgent. Could for example be a revolving version of a circular logo, or a pulsating square logo. Depending on the urgency, the animation could repeat endlessly (highly distracting) or once in a while. Use with care :)
Pop-over box in a corner of the screen. This should give some context info, the primary object of which is to enable the user to decide whether or not it's worth checking out immediately. Could afford clicking by using a "More" link or big "+" sign.
Focus the application window immediately. Enormously intrusive, and should not even be used in case of nuclear meltdowns (what if the user already knows the meltdown is occurring, and is looking elsewhere for a solution?). Just don't.
I think an answer depends highly on the specifics of the UI you are working within. However, for general guides
The GNOME desktop environment's human interface guidelines (HIG) is a useful resource if your environment is GNOME, and perhaps informative if it's not. There is a section on using the "desktop notification area": http://library.gnome.org/devel/hig-book/stable/desktop-notification-area.html.en. This covers not overloading the area, etc. (perhaps analogous to the win32 tray).
Apple have their own HIG document. Part of this describes using the Dock for conveying status information: http://developer.apple.com/documentation/userexperience/Conceptual/AppleHIGuidelines/XHIGMOSXEnvironment/XHIGMOSXEnvironment.html#//apple_ref/doc/uid/TP40002721-TPXREF139
Apple also have a separate HIG document for the iPhone. there are several notification techniques described within, e.g. "alerts" http://developer.apple.com/iphone/library/documentation/UserExperience/Conceptual/MobileHIG/ModalViews/ModalViews.html#//apple_ref/doc/uid/TP40006556-CH11-SW1 which are specifically described as to be used for critical information (due to their disruptiveness).
Several apple iphone apps adjust their icon to convey some status info: e.g. mail, SMS, phone all indicate the number of outstanding mails, SMS messages, or missed calls/voicemails as part of their launch icon. I can't, however, find any reference to that in a cursory scan of the apple iphone HIG.

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