March 5, 2015

42 Mobile A/B Testing Terms You Need to Know

As mobile continues to eat the world, the number of A/B tests running on mobile applications continues to grow. While A/B testing isn’t new, the vocabulary to talk about A/B testing mobile apps is new for many people. Succeeding in mobile A/B testing starts with the right vocabulary. Following in the footsteps of the 14 CRO Terms You Need to Know article, we have created one for a mobile lexicon. This alphabetized glossary of 42 terms and examples will help you communicate about mobile optimization.

two iOS phonesAs mobile continues to eat the world, the number of A/B tests running on mobile applications continues to grow. While A/B testing isn’t new, the vocabulary to talk about A/B testing mobile apps is new for many people. Succeeding in mobile A/B testing starts with the right vocabulary. Following in the footsteps of the 14 CRO Terms You Need to Know article, we have created one for a mobile lexicon. This alphabetized glossary of 42 terms and examples will help you communicate about mobile optimization.

  1. Acquisition: The process of driving users to install an application and/or use the app by either paid or organic marketing.
    • We’re currently testing many different acquisition channels to find the one with the lowest cost per user.
  2. APK (Android Application Package): An APK file is the file format used for installing software (usually games or apps) on the Android operating system. (Read more about APKs.)
    • Android Developer: “We haven’t officially released our app yet. Download our APK to see what it looks like.”
  3. App permissions: Any app must have the explicit permission from the user to access certain client/device-side capabilities like GPS and Push Notifications.
    • In iOS, you can launch app permissions during a user’s first-time use. Android requires gathering app permissions upfront before someone downloads the app.
  4. App ratings/reviews: User reviews for applications that are visible in the app store.
    • App ratings are one of the most visible components of an app’s listing and do influence a person to tap through or download. (Learn why app ratings matter and how to get great ones.)
  5. App Store Optimization (ASO): The process of improving the visibility of an application in an app store (iTunes or Google Play). The goal is to rank highly in an app store’s search results and top charts rankings. (Learn more.)
    • The App Icon, App Name Keywords and featured screenshots are all components to think about with App Store Optimization.
  6. Assets: Images or any file used in the application.
    • I keep the image used for the app open screen in the Assets library.
  7. Average Revenue Per User (ARPU): A measure of how much income a business generates given the size of its user base. Calculated by dividing revenue by the number of people using the app.
    • The ARPU would skew if the application was a game with a freemium and paid model. For a paid app with no in-app purchases, revenue comes from the app purchase price.
  8. Average Revenue Per Paying User (ARPPU): Calculated by dividing up the revenue amongst the users who pay anything at all for the app.. (ARPU vs. ARPPU)
    • Average Revenue Per Paying User is more consistent for businesses with a subscription business model. ARPPU will be much higher for a freemium game than the ARPU because a very low percent of people ever pay.
backgrounding-ios backgrounding-ios-swipe
  1. Backgrounding: When you hit the “Home” button and returns to the Home screen, leaving the app you were previously viewing in the background. (To see what apps you have backgrounded right now, double tap the “Home” button!)
    • Backgrounding is a very efficient way to toggle back and forth between apps.
  2. Cocoapods: A framework that allows you to easily install and manage SDKs.
    • I use cocoapods to manage all my third party libraries (SDKs) like Facebook or Twitter login authentications.
  3. Code block: Any section of code that is grouped together. In Optimizely, a code block is a set of code you can test.
    • We used code blocks to test out an entirely new app onboarding experience.
  4. Conversion: A successful completion of a specific goal, such as a purchase, or install to active user.
    • A/B testing different app experiences is a smart way to increase conversion.
  5. Daily Active Users (DAU): A metric of how many users engage with an app in a day. A key metric to determine popularity of an app.
    • Our latest release had a positive impact because we’ve seen an increase in Daily Active Users.
  6. DAU/MAU Ratio: The ratio of Daily Active Users to Monthly Active Users. This ratio is an indicator of potential, a metric for the “stickiness” of an app over a 30 day period.
    • There is no one “good” DAU/MAU number, they vary a lot based on whether the app is paid or free, a game or something else, etc. A successful one would have a DAU/MAU close to 50%. (Learn more)
  7. Cold start: When a user launches an app from the very beginning, instead of resuming from a backgrounded state.
    • The load time may be longer when an application launches from a cold start.
  8. Custom Views: A custom view is one that isn’t built using the platform’s built-in UI components.
    • I use custom views to create a wide range of visual effects.
  9. Drawn views: A view that has no defined structure.
    • Game applications usually use drawn views to build the graphics.
Snapchat first-time user onboarding experience

Snapchat’s first-time user experience. Read more about designing a optimal first-time user experience.

  1. First-Time User Experience (FTUE): The first experience a brand new user has upon downloading and launching an app. (7 tips to improve your FTUE)
    • The first-time user experience for the Facebook app is personalized depending on device and operating system.
  2. Foregrounding: When a user double-taps the “Home” button and clicks on a backgrounded app, bringing it to the fore. Also can happen if the user taps the icon for an app that is currently in the background.
    • Foregrounding apps usually provides faster reload times compared to cold starts.
Nativs versus hybrid apps

Native vs Hybrid app. Source

  1. Hybrid App: An App built as a Native app, but implements some functionality via web. They are written with web technologies but have cross-platform compatibility and run locally on devices. (Learn more)
    • Native apps provide the fastest performance, at the cost of being more complex to code. Hybrid apps, are easier to build, but not as fast. PhoneGap/ Apache Cordova, Appcelerator, Xamarin are platforms to help you build Hybrid Apps.
  2. In-app purchase: Purchases made from within a mobile app. Users typically make an in-app purchase in order to access special content or features in an app such as power-ups, restricted levels, virtual money, special characters, boosts, etc.
    • The 500 gems you bought from Clash of Clans was an in-app purchase.
  3. Interface Builder: A software development application part of Apple’s developer toolset that allows developers to build and design user interfaces in a graphical way.
    • Interface Builder is helpful to build the design of an application without any code. (Learn more about Interface Builder.)
  4. JSON / Configuration: Javascript Object Notation. The format of the configuration file delivered to the app by a CDN. JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write. It is easy for machines to parse and generate.
    • We use JSON to pass in data to our application.
  5. create an app people love

    Learn more about A/B testing in action by downloading the eBook, Create an App Users Love.

    Lifetime Customer Value (LTV): LTV is a prediction of net profit attributed to the entire future relationship with a customer. (Read about why it’s important for apps.)

    • We make regular updates to our app based on user feedback and measure the impact over time on LTV.
  6. Live variable: In Optimizely, a live variable is any aspect of the app that you can change.
    • We use live variables to test out different discount percentages or number of search results delivered to see how it affects our user engagement.
  7. Locale: A unique identifier to indicate the region a user’s App Store is set to.
    • The locale for a English-speaking residents of the United State is en_US.
  8. Mobile web: Accessing the world wide web on a handheld mobile device.
    • Often times, businesses will apply successful designs from their apps to their mobile web experience. Open your iPhone browser to see our mobile website.
  9. Monetization: App Monetization is the process of converting the value of the application into revenue.
    • Our plan for monetization includes providing a monthly subscription plan and adding in-app purchases.
  10. Monthly Active Users (MAU): The number of unique users per the past 30 days. In other words, the monthly aggregate of daily active users.
    • Although we have acquired new users, our number of monthly active users has stayed the same from the previous month.
  11. Native app: A smartphone application coded in a specific programming language for the given operating systems
    • Objective C and Swift are used to build iOS application and Java is used to build Android applications. Native apps have more flexibility to take full advantage of all operating system features.
  12. Onboarding: The series of steps or screens a brand new app user experiences the first time opening an app that are meant to educate the user on the app
Push notification from Mint Request for push notification
  1. Push notifications: A notification delivered to the home screen.
    • We’re experimenting with the type of in-app experiences that trigger push notifications.
  2. Phased (Staged) rollout / Beta deployment: A strategy that involves releasing a new feature or design to a portion of users to get early feedback/QA before releasing it to 100% of the user base. (Learn more about the benefits of phased rollouts)
    • For our latest feature release, we did a phased rollout to 10% of users to gauge interest. This is helps minimize risk in deploying new features.
Responsive design

Visual representation of responsive design.



  1. Responsive: A web design approach aimed at crafting the site to provide an optimal viewing experiences on any device and any screen size.
    • Your new responsive website looks really nice when I opened it on my mobile browser.
  2. Rollback (verb and noun): An operation where it returns the application to some previous state
    • We rollback features that are not adding value for our users.
  3. Retention: A way to measure how many of your customers/users come back over time, often measured at specific intervals like “7-day retention”.
    • 30-day retention and 90-day retention are the best measurements to see how engaged your users are with your application.
  4. SDK: Software Development Kit – a programming package that enables a programmer to develop applications for a specific platform, usually includes APIs and programming tools
    • The Crittercism software development kit allows you to use their third party code for your application to monitor crash reports. This saves a lot of time from re-creating a crash analytics platform from scratch.
  5. Segue: Transitioning between different view controllers in an iOS Storyboard.
    • What is the function that initializes the segue from one to another?
  6. Session: A unit of someone using an app. The equivalent of a visit for a website.
    • We saw a huge spike in sessions yesterday after sending an email blast to our user base.
  7. Average Session Length: A metric that aggregates the amount of time users spend in the application before exiting calculated by dividing the total duration of sessions by number of sessions. Also referred to as time in app.
    • The average session length increases between the hours of 5 and 8 pm when people are commuting home from work.
  8. Storyboard: A graphical representation of your app — a container for all your Scenes (View Controllers, Nav Controllers, TabBar Controllers, etc) Learn more on Stackoverflow.
    • We use storyboards to create better user flows in the onboarding experience.
    • Source:
iOS view hierarchy

iOS view hierarchy

  1. View hierarchy: The layers of screens that create an app interface.
    • As Apple puts it, “Managing view hierarchies is a crucial part of developing your application’s user interface. The organization of your views influences both the visual appearance of your application and how your application responds to changes and events.” (Learn (a lot) more about view hierarchies.)