Vfrdtyky

I am designing an app for iOS where I need to prevent the user from unintentionally trigger an alarm (the action of calling for emergency should be easily accessible, but at the same time it should prevent any accidental initiation).

I don't want to use a confirmation dialog since it requires the user to read and looking for a button in a different position (it seems like too much friction on the other side).

To use a 'slide to' action button occurred to me initially as an good idea, similar to what was/is used to unlock an iPhone screen, but then I run into this topic: Creating a “Slide to power off” like slider on iOS, basically saying that Apple discourages usage of these kinds of components, and they refuse to publish such an app in the store.

Do you have any experience with this kind of user scenarios? Or do you have experience with Apple refusing to publish your app for such reasons?

First, regarding answer that you linked, I think what Apple was having an issue with is the use of the same UI as their slide to power off, not the use of that UX/interaction. They just don't want it to be styled to resemble their power off slider as to not confuse users. If you were to create say, a small blue slider, or a slider that moves in a circle pattern I think you'd be fine.

However, if you want to play it safe, what about press to hold like this:

Screen recording from MapMyRun app

In the .gif, a user is pressing the "hold to finish" button, which triggers a roughly 2 seconds "finshing" state where a user can let go and cancel the action, or after two seconds the action, in this case "finshing", triggers. There is a visual progress indicator to show the user that they are performing the action and how long until the action completes. You could also experiment with increasing the time or providing haptic or audible feedback to prevent false presses. This also meets your need of not having to read or click anywhere else.

To send money in my banking app, I must drag a symbol into a target. It is difficult to do accidentally, but quick to accomplish. It may be difficult for someone with limited dexterity or someone who is distracted.

I haven't thought this through, but there might be mileage in considering the physical equivalent. On many control panels, such as in power plants or aircraft, the especially dangerous actions have a switch cover that must be lifted before the button can be used.

My suggestion is a control that's normally in a "locked" state, and takes an action to unlock it (perhaps just a press of that control, perhaps a slide). When it's unlocked, it can be used; if it's not used within a reasonable time, or if some other control is used first, the cover "slides back" automatically.

Although it is functionally equivalent to having a "confirm" button or a popup-menu confirmation, the metaphor is somewhat different, and can be presented in a different visual form.

Additional ideas from this article:
https://www.smashingmagazine.com/2018/01/friction-ux-design-tool/

1. Delaying the action and allow a window time for users to "undo"


2. Extra step for security, such as asking for fingerprint


3. Other types of authentication such as re asking password or 2-factor authentication.

Other articles dealing with the same topic:

• https://uxdesign.cc/friction-as-a-function-in-user-experience-make-me-think-390ee17c6cf5


• https://uxplanet.org/when-friction-in-design-is-good-for-ux-e2dd82cfab67

Let's Talk User Flows & Navigation:

User Flows are a series of steps a user takes to achieve a meaningful goal ¹.

From The Science of Great UI by Mark Miller - When User's Navigate through a task, the path they take to accomplish it can be broken up into into individual steps for each context shift.

• 
  Path - Set of Steps needed to complete a task


• 
  Step - Effort to complete sub-task

And each step has two properties:

• 
  Length - Amount of Time to complete


• 
  Width - Amount of Difficulty to complete.

Difficulty can be broken up into:

• 
  Mental Difficulty - Remembering information, calculations, decisions


• 
  Physical Difficulty - Increases with precision
  
  
  
  
  • See Fitts' Law: the smaller the size of an area, the more time it takes to move a mouse cursor to that area.
  
  
  
  

So if you want to make navigation easier, you can do the following:

1. 
   Decrease # of steps - ex. Auto-fill city based on zip
   


2. 
   Widen steps (make easier) - ex. Increase button size on common actions
   


3. 
   Shorten steps (reduce time) - ex. Google's autocomplete suggestions
   


4. 
   Add Alternative Steps - ex. Find account by Email or Phone
   

Contrastingly, if you want to make navigation harder, you can do the opposite:

1. 
   Increase # of Steps - ex. "Are you sure" modal dialog
   


2. 
   Narrow Steps (make harder) - ex. Slide to unlock rather than click
   


3. 
   Lengthen Steps (increase time) - ex. Require long (timed) press rather than click
   

So all of those tools are within your disposal, and depending on your use case and the severity of performing the wrong action and the difficulty of restoring to the Last Known Good State, you might need any combination.

For example, if the alarm will trigger a nationwide missile alert, you might want to introduce a lot of difficulty, time, and informative content. If you just want to prevent accidental clicks from pockets, increasing the difficulty/precision is probably sufficient. If users might not be aware of the risks of setting an alarm, the introduced friction should include copy to let them know

Here's an example from GitHub that I think introduces severity well

Friction does not have to equal Frustration, so ask your users and get some good telemetry :)

I'm a fan of GitHub's approach where you have to type in a repository's name as confirmation when deleting a repository.

Your user could be asked to type in something like "911", which is very difficult to accidentally do. The string could be adjusted for locale and desired difficulty.