AG-9: Carousel

The Carousel design pattern is used to show featured items in vertical list of items with pictures and descriptions, but, unfortunately, many mobile app implementations do not offer satisfying carousel experience.

In this pattern, the user is able to view several images of products across a row with horizontal swipe to navigate from one product to another. Typically, an arrow indicates the direction of the carousel and apart from the featured item, there are other items partially hidden.

The problem

The functionality of the Carousel is intuitive, however, it’s necessary to provide visual information regarding the direction of the carousel and also button alternatives for the swiping gesture.

The pattern works well on small devices because it uses the screen space efficiently, but there are some implementations and variations that have serious acessibility and usability problems.

Here, we can see that the user can get lost, just because have no slider indicator.

The recommendations

• At the end of a carousel, it’s necessary to give the user the opportunity to see more results. A “See more” link can be added and redirect the user to a page, listing more products.

• Some implementations presents vertical scrolling that are not smooth. The scrolling of this pattern must regard the user with the option of fast and precise scrolling, without keeping the user stuck and limiting the user’s navigation.

• The implementation should always indicate the scrolling direction. Also, the carousel shall provide a unique starting point, presenting the far left item first.

• An infinite carousel makes the user tired and is not recommended. A good amount of items varies from 8 to 20 items. When the carousel is infinite or has too many items, the user feels bored or tired.

• A carousel does not replace any kind of list of items.

• It’s importante to maintain consistency in the item’s structure, so if one item has image and description, all items must have the same information. Also, the items must have meaningful images and descriptive texts in few words.


And here is another correct way of representing a carousel:

AG-8: Sliders

Sliders are intuitive in terms of touch interaction, because they mimic the interaction obtained in the real world. Thus, the common slider implementation is usable both on mobile with touch screen and desktop with the precision of the mouse.

The problem

There are two possible implementation of sliders: the continuous and the discrete slider, and they have their pros and cons.

The continuous implementation of a slider gives the user more control over the selection range, however,  it’s difficult to select a specific value in large interval. So, with continuous slider, the precision may not be satisfactory.

Also, another issue that rises with continuous sliders is that the user has no idea of sizes and values that are currently avaliable. This can lead to unwanted results.


Another variation, is the slider with two selections. In this implementation, the user may select using the same interval a lower and higher bondary for the filter, and the problem with this implementation is that in some cases, when the range of values is too big, the user has trouble selecting a small interval, as the slider selection icons can be overlaid or cannot be possible to perform such action.

The GIF below, we can see another problem using the slider, when the user can’t reach the number 4000.

The recommendation

• The values of the slider selection shoud appear above the pegs, with this, when the user clicks to select, the user’s fingers will not cover the value.

• There should be an alternative form of selection that is different from sliding a peg. This can be done by adding an input element on top of the slider, where the value can be manually changed by typing a new value or the value can be automatically changed when moving the selection along the slider’s range. This option is useful for many disabled users with motor impairments and for those who use screen readers.

• In order to give the user more control over the selection, the slider could probide more information regarding the number of itens avaliable in a position. A way of implementing this, is by dividing the slider positions by number of items in a range, With this, a certain distance of movement on the sliders axis represents and equal aboslute change in value.

• Another way of presenting the user with more information regarding quantity of results, is to present a histogram based on the number of items in stock attached to the slider.

This is how your slider should look like in practice.

AG-07: Select and Dropdown

Select and Dropdowns are well defined interface design patterns, however, in some situations, the adaptation for mobile is not effective and accessibility and usability is affected.

The problem

When using Select and Dropdowns, depending on the application, can be a little bit annoying. If you have to set your location, for example, and have to choose your country, a big list of countrys will be shown to the user, and you have to search for your country by scrolling down or up.

If you are using a smartphone, for example, is even harder because of the screen size limitation and your finger position, that can cover the information you need.


On the other hand, if you have to search in a small list, like the “City name” exemple above, the user will have no problem.

The recommendation

  • Dropdowns items can be affected by context. For example, in a list of drugstore, the list should be ordered by proximity to the user. In a list of airports, the same idea
    may apply. On other contexts, the list could be ordered by the most selected item or
    any other classification or rank that may be reasonable.
  • Another solution for a large number of items is to split the list into two or more selects. This approach is not the best and many times cannot be meaningful, but it’s a valid one on some cases
  • A different approach to the dropdown situation with many items is to provide filters or categories in order to reduce the number of items displayed. This approach is already used on many examples found, however, it increases the number of clicks that the user needs to perform.
  • Lastly, one more approach is a hybrid search plus select implementation where the select box is also a search input and the user may type in order to filter the items. This approach is extremely valid as searching for the item may be faster than manually searching. One downside is that on mobile devices input entry may have complications for some users, due to the small screen.

AG-6: List and Pagination

List and Pagination are related to the “Navigation” category which is explained by the fact that the user navigates through the items in a list.

On web desktop, list navigation is usually implemented with pagination controls at the bottom or top of the page. This way, users have more control, like skipping, jumping, returning pages.

On mobile applications, an interface design pattern that has been widely used for list navigation is the infinite list, just like Facebook, where you scroll and the results are automatically loaded and displayed.

The problem

Through the infinite list is more minimalist and clean, it raises serious accessibility concerns. On situations of low bandwidth, infinite list may present long waiting times while loading to display, and this may cause the user to think that the application is not responding or that the list reached its end. Also, visually impaired users may not understand what is happening because the screen reader may not be able to correctly inform the user that the application is loading new information.

Another problem of the infinite list is that does not provide any information regarding the position on the list, where users can be easily lost, as you can see in the example below.

The recommendation

Knowing this issue, the best way to deal with this kind of problem is the Pagination, even in mobile devices. It’s more intuitive and provides the user control, so he can navigate through the pages easily.

The negative point of using Pagination is that requires more clicks and actions from the user.

sem título

It’s important to provide filtering and ordering options in order to lower the number of items in the list.

AG-5: Data Tables

Zoom in, zoom out, flip the phone… Argh!!! Data tables are always a problem when we have to visualize on the screen, but, in most of the times, is the best way to show the Data to users, and we can’t escape from it.

The problem

Data tables with a large amount of data on a form of a table are hard to be displayed for the user, even if they are using a computer. On a mobile device is even harder, because of the screen size limitation.


As you can see, the image in the left is showing us the content of the table, but you have to scroll so see the rest.

The image in the right show us the full table, but it’s very small, and you have to zoom in to read.

The recommendation

  • Table borders are used by screen readers for identifying a data table. This means that if a screen reader finds a table that does not have defined borders, it will possibly parse the table as a layout table and will not read its contents correctly.
  • Some screen readers have difficulty identifying commonly used operands and characters usually used in data. One example is the use of hyphens to demonstrate negative numbers (for example -99.99). The screen reader will not read the hyphen in most cases, for this, it’s necessary to use the correct minus Unicode character.
  • On some framework implementations, tables are not defined with the usual <table> HTML tag, but defined with <div> or custom tags. With this, the screen reader will not be able to understand the content.
  • Data tables as any other content must have well defined ARIA attributes.
  • There are other issues with how to present a data table so that screen readers can read it that are presented on

AG-4: Input

We all had problems with input fields when using an application. Sometimes we forget what we are filling… or is this a problem of the application?

Here you will find some recomendations about the Input fields.

The problem

In addition to this problem, people normally uses Placeholders to guide the users, but sometimes its not the best way do deal with it.

Placeholder is just a word in the text box that indicates the user what to type.


The use of placeholders alone saves the designer space for elements, but dissapears when the user starts typing, wich instantly removes all the context of the input field. They usually are presented with low contrast to the background, which may spoil the experience of users with visual impairments or users with situational disabilities caused by screen reflection in the screen.

Besides that, when an input field does not have a label, the hit area of that element is reduced, and this can cause troubles to some kind of users.

The recommendation

A solution of most of these problems is the appropriate use of label and placeholder together.

Labels have to be succinct, short and descriptive, so that users can quicly identify what information is required. Also, they must present the necessary information for the user.
For exemple: on a login form where the user can use a username or an email to access the account, the label must contain “username or email”.

The image below shows the use of the label and the placeholder together:

Account Creation

Placeholder and Labels should never be in all caps, as it’s more difficult to read and harder to quick scan.

AG-3: Icons

Everybody know what is an icon, right? A simple button with an image or a text. Icons makes the application beautiful and easy for the users to navigate, but, sometimes, if used incorrectly, can cause confusion.

The problem

Sometimes, icons are not displayed correctly because the image or the color is not the best way to representate the meaning of it. This is a problem, because new users or users that have some kind of disease like colorblindness, for example, will have trouble using the application.

Some younger users don’t know or never saw a floppy disk, that is commonly used as a “save” icon. They just know it because all “save” icons are representated like it.


The recommendation

It’s necessary to correctly choose meaningful icons that will actually help the user. One great way of doing this is choosing icons that are avaliable in the mobile plataform, because it appears all the time when we are using an application, and it’s easy to associate the image with the meaning.

Here we can see an exemple of the Icons in the Netflix app.
Here we can see an exemple of tje Icpms in the Spotify app

Always remember to put some text to explain what does the icon mean, because only an image, sometimes can cause confusion.

Neutral colors are the best way to representate the icon too, because, in most of times, the color doesn’t mean anything, but for people that is colorblind can cause confusion if someone says, for exemple “click in the red circle”. We can avoid that, right?

AG-2: Tab Navigation

Everyone loves Tab Navigation. Why? Because it’s simple, direct and fancy! It doesn’t hide navigation options. They can be avaliable all the time and the user has easy access to the navigation bar without needing to open a drawer, in order to locate wich navigations options are avaliable.


Besides that, another important contribution of the tab navigation is that the tabs communicate the user about the current location by visually featuring the current position in the related navigation option, and that is good also for people with cognitive decifiences, because its pure visual.

Cool, isn’t it? But how nothing is perfect, there is some kind of “problems” using this feature.

The problem

Thinking in mobile devices, we all know that the screen size have limitations, right? So, the Tab Navigation can hold up to 5 navigation options, in order to be able to fit in the screen, with appropriate font size.


The image above shows a tab navigation with 6 navigation options, and, as you can see, there are informations that are missing, like the hamburger menu and other products sections that are shown in the screen, like the backpack, for example.

The recommendation

In cases where we have more than 5 navigations options, there are some approaches that we can do to solve this.

The first approach is to add a last option in the Navigation Tab called “MORE“, or another label that fits. By doing this, you keep the navigation tab clean and the user will not get lost, because it will open a navigation drawer that will guide.


Now, the image above is showing the button “see more“, where you can see other products that is showing in the “Home Screen” (you can see that the “home” button is indicating where you are navigating) and now the hamburger menu is there too, where the user can see the account options.

The seccond approach applies the use of a horizontally scrollable navigation tab bar. By doing this, you are going to save some space without losing the pattern. The user is just going to scroll and search for what he wants to.


The downside of both approaches is that they still have discoverability issues.

AG-1: Hamburger Menu

Hamburger menu is a kind of navigation interface design pattern mostly used on mobile applications that consists in presenting navigation options that are initially hidden and that can be triggered by the click of a button.

The problem

The problem with this approach is that the navigation is hidden from the user that needs to have previous knowledge to understand that the menu can be accessed by clicking a button. The menu icon has low information scent, and, even with a label called ‘Menu‘, users may still not use the navigation as they do not know which options are avaliable and don’t even click the button.

In the documents analysed by Vitor Casadei, several uses were presented about big companies that initially adopted the hamburguer menu, but soon changed it to Tab Navigation. Some companies as Facebook and BBC used the drawer navigation, but due to the low discoverability that this type of menu provides, they identified that users had problems locating sections and menu options.

Here we are going to see an exemple where the hamburguer is not in an appropriate form:


The recommendation

When dealing with patterns that directly affect the discovery of content, the solution is not always simple. However, some recommendations are effective:

• When using hamburguer menu, use appropriate and explanatory terms for menu items;

• Avoid creating too many menu items. This can lead to an extensive list of options that are easily ignored and, sometimes, not well displayed on mobile devices.

• Although the menu is there, it’s positive to tell the users that what are the main navigation options avaliable on the front page.

Now, we can see that the recommendations above was taken in consideration.

Overcoming Accessibility Barriers with Design Pattern

The problem

When dealing with complex processes on mobile application, many times there is a big number of steps that the user must follow in order to complete a task or achieve a goal.

Although, it may seem more organized and appropriate to split actions in multiple steps on multiple screens, this segmentation of information requires the memorization of previous actions. The problem is that people with cognitive deficiences may struggle to remember previous actions or information! This problem affects the elderly people too.


Even users that do not suffer from any disability may have some difficulty following actions that are split in multiple screens when using the mobile device on busy enviroments where the user must be aware of its sorroundings (in a bus, for example).

The recommendation

One simple but effective solution for improving the general navigation experience of users and provide accesible feedback to any user, is to use breadcrumbs or hints of some sort that inform the current location. Although, breadcrumbs are a common practice on web development, it’s rarely used on mobile.


With the information of the current location, older users that often get lost on mobile applications and are insecure about how to undo some action, for example, will be able to understand better where they are. It’s important to find the appropriate place to display such information, as for example an action bar or a simple field above the page title.