Mobile apps in environment of limited connectivity new rubric solutions
- 1. Technical Challenges of Designing Mobile Apps in an Environment of Limited Connectivity Anurag Dwivedi & Pradeep Warrier
- 2. Objectives of today’s discussion Share • Scenarios which present the need for Offline functionality • How we have thought about making these choices and issues to consider
- 3. Why Offline? Is connectivity really an issue? • Is this even relevant –in an era of 3G? Availability - Uninterrupted access – Only for the ads! Cost – Is a real issue – particularly if large amounts of data involved User experience - Expectations driven by usage context
- 4. User expectations determined by usage context
- 5. Let us consider a potential application in Education…. Consider you are a student with a tablet… You are enrolled in a distance learning program provided through the tablet You use the “Distance Education” App for the following: 1. Study the content – View Material, sample questions and their answers 2. Ask questions and get answers – to clarify doubts that you may have 3. Take tests – corresponding to material studied 4. Get performance evaluation and suggestions on next steps: Move on to the next topic Revise existing content Practice more problems Provide or direct the student to new content that might be helpful
- 6. Online - Offline Apps - the critical choices • What functionalities are to be provided in an offline mode? • What data is on the device? How do we handle this data? • How do you implement online-offline apps? How do we ensure fast, accurate data synchronization? How do we secure the data on the device? How do we handle bug fixes, patches and enhancements?
- 7. Thinking about online/offline in the context of user expectations … Performance evaluation Ask questions High and feedback Important to keep Simulated in mind that INTERACTIVITY Probably online*/ interactivity/Hybrid responsiveness and interactivity Simulated interactivity solution are just two important elements of user experience and ? Study Content/ Take not the only Tests factors…. Low Other considerations more relevant Probably offline* RESPONSIVENESS Low High * Ultimate decision would need to factor in other considerations besides these
- 8. What data to store on the device? • Qualify the data for offline use ▫ Dynamic vs. Static ▫ Duration of data use ▫ Size of data ▫ Business sensitivity of data • Affects the choice of technology ▫ Native vs. HTML5 ▫ Storage on the device (local sql/ local files) ▫ Minimum requirements of device
- 9. How to Synchronize data between device and server? • Distribution of data to device ▫ Data filtering mechanism, based on feature/ user requirements (e.g. test data may be different for different users) • Conflict handling ▫ Feature specific resolution mechanism to handle conflicts, in data that can be changed by multiple users (e.g. HOD vs. teacher providing feedback) • Data synchronization mechanism between device & server ▫ Order Preserving nature of synchronization on both the ends- device & server (e.g. 1st test attempt vs. 2nd test attempt) ▫ Before synchronization, Record state of data on device (e.g. avoid sending the same questions again, send only incremental content) • Configuring synchronisation ▫ User preferences (e.g. when student is roaming or on a high cost network) ▫ Synchronisation sequence to manage peak load
- 10. Now that the data is on device, secure it! • Device & data protection for exchange of content with server ▫ Authentication & Authorization check for both user & device (e.g. student should not be able to use another device to get data from server) • Encryption of data storage on device ▫ Categorize the data and identify security needs for data (e.g. test results vs. syllabus information) Simple textual storage - sqlite or simple file (e.g. for syllabus information) Encrypted storage – for sensitive information Can make use of same storage mechanism but content to be encrypted (e.g. for test results) • Handling cases of misuse or loss of device: ▫ Detection of such a scenario – encourage users to report? ▫ Wiping out application and data – on multiple incorrect logins
- 11. And ……Application Life Cycle Events • Upgrade needs to take into account ▫ Technical constraints (Ensure no loss of data, supporting multiple versions) and ▫ Operational constraints (no/minimal user discomfort, large user base) • Handling of multiple version of app ▫ Not practical to upgrade all users at the same time (e.g. some users may be on leave when we want to upgrade) ▫ Backend need to support the case of different clients having different version for same underlying backend. • Upgrade of self owned components versus standard framework components. (e.g. how to proceed when Android releases some relevant change)
- 12. Resource Selection • Server ▫ Hardware requirement for server – Better DB (as usual), though processing requirements can be compromised compared to online case. ▫ Peak load can be lowered by synchronization strategy. ▫ In the on-demand cases, flattening of peak can help in making cost effective choices. • Device ▫ As more data processing is needed, will need good I/O capability. ▫ Needs good battery life.
- 13. Thank You! Contacts: Anurag Dwivedi – anurag@newrubric.com Pradeep Warrier – pradeep@newrubric.com