Introduction of a novel technique and evaluation of interaction techniques between touchscreen devices
Goal
Conceived and developed the innovative Pinch-To-Move interaction for data transfer between touchscreen devices.
Conducted a comparative evaluation of various interaction techniques for transferring data between touchscreen devices.
Role
Lead UX Interaction designer and developer
Context
In today's world of multiple touchscreen devices (phones, tablets, interactive tables), it's surprisingly hard to quickly and intuitively share information between them. This project aimed to solve this problem by creating a gesture-based method that felt natural and easy to learn.
I defined and developed Pinch-To-Move, an intuitive, gesture-based interaction technique, that allows users to easily transfer data between touchscreen devices with a simple pinching motion.
I evaluated Pinch-To-Move in comparison to three other existing data transfer interaction techniques: the ‘swipe up’ touchscreen gesture, the ‘throw’ 3D gesture and the simple ‘double tap’ on the touchscreen.
Process
Research: I conducted literature review of existing data transfer techniques and identified potential usability challenges. I conducted 24 user interviews to understand pain points and needs.
Ideation: I led brainstorming sessions to generate gesture ideas and produced wireframes of the potential interactions.
Prototyping: I created a low-fidelity prototype for initial testing and high-fidelity prototype with refined gestures and visual feedback.
Experiment: I designed and implemented an experiment involving 24 participants. I defined task-based scenarios to evaluate effectiveness and efficiency and conducted quantitative (task completion times) and qualitative (user questionnaires, usability testing) data analysis.
Iteration: Based on my findings, I made iterative improvements to the gesture and interface and refined the technical implementation for smoother performance.
Experiment
Persona - Understanding the user
Scenarios
The target users were people familiar with touchscreen devices, including:
Professionals: People who need to share data during meetings or collaborative work sessions.
Casual Users: Anyone who wants to quickly send a photo from their phone to a larger touchscreen, or share content with friends.
For the experiment, the primary users for whom I designed for were professional users.
I conducted the experiment on the following 2 scenarios:
Business Meeting: A team is brainstorming around a large interactive table. Team members send digital post-its from their touchscreen devices to the main touchscreen table.
File Sharing: In a casual setting, users share photos from their phone to a large interactive table.
Interaction techniques I evaluated
I designed and implemented the following 4 interaction techniques between the tablet and the interactive table:
Double tap
The user doubletaps the postit/image on the tablet twice to send it to a random spot on the interactive table.
Swipe
The user swipes the data upwards on the tablet to send it to a random spot on the interactive table.
Throw
The user makes a throwing motion with their hand on the tablet to send the data to a random spot on the interactive table.
Pinch-To-Move
This is a novel interaction technique I created following the ideation sessions with the team. The user pinches the data on the tablet to pick it up, then pinches open at the desired location on the interactive table to drop it.
Description of the experiment
Upon arrival, participants completed a questionnaire with their personal data and their experience using touchscreens. Two applications that are typically used in collaborative settings were chosen for the experiment: image sharing and brainstorming.
The participants completed five tasks that illustrate the different use case scenarios for transferring data between a tablet and an interactive table.
Task 1 - Send one item from the tablet to the interactive table
Participants sent one image from the tablet to the interactive table using all of the interaction techniques in a randomized order. This task was chosen to simulate a simple transfer of a file to the interactive table without any specific target destination.Task 2 – Send five items from the tablet to the interactive table
Participants sent five images from the tablet to the interactive table using all of the interaction techniques in a randomized order. This task was chosen to simulate a more complex transfer of several files to the interactive table without any specific target destination.
Task 3 - Send one item from the tablet to five specific locations on the interactive table
Task 4 - Send three items from the tablet to five specific locations on the interactive table
Task 5 - Brainstorming Observation task
At the end, I included an observation task simulating a brainstorming session, where participants had to create and send 5 post-it items to the table and 5 towards a specific person/location, who was supposed to be sitting on the other side of the table.
After each task, participants filled a questionnaire rating the data transfer techniques on a continuous 10-point scale and at the end, they were asked to fill in a general 6-point Likert questionnaire about their opinions on different aspects of the gestures, for example whether they were easy, quick, efficient, tiring etc. Task completion times for each of the interaction techniques, as well as the qualitative data from the questionnaires, were collected for analysis.
I conducted a statistical analysis on the task completion times, as well as the user preferences. Dependent t-tests were performed for both the task completion time measures and for user preferences for each couple of techniques with 99% confidence interval for the mean difference.
Findings
User feedback
I tested Pinch-To-Move with 24 participants and compared it to other methods (double tap, swipe up, throw). Here's what I found:
Preferred for Precision: Pinch-To-Move was the clear favorite when users needed to place data in a specific location on another device.
Efficient for Multiple Items: When sending multiple files, Pinch-To-Move was the fastest and most efficient method.
Learnability: Most users found Pinch-To-Move intuitive and easy to remember.
Fun Factor: Participants described Pinch-To-Move as "magic" and enjoyed its natural feel.
Additional Insights: Challenges & Lessons Learned
Not Always the Fastest: For single-item transfers without a specific destination, other methods were sometimes slightly faster.
Room for Improvement: Some participants found the Pinch-To-Move gesture a bit tricky to master at first, and there were some technical challenges related to hardware sensitivity.
Future considerations: Addressing multi-user scenarios requires further exploration of user identification methods.
Quantitative analysis
Task Time:
Single Item Transfer: For transferring a single item to a general location, Double Tap and Swipe Up were slightly faster than Pinch-To-Move (approximately 15% and 10% faster respectively). This is likely because these gestures are executed entirely on the tablet, while Pinch-To-Move requires approaching the target surface.
Multiple Items/Specific Locations: Pinch-To-Move significantly outperformed other methods when transferring multiple items or placing items at specific locations on the target surface, showing an average improvement of 25-30% in task completion time. This highlights its efficiency and precision advantages.
Task Preference:
General Preference: Overall, 62.5% of users preferred Pinch-To-Move due to its intuitiveness, versatility, and ability to handle precise placement.
Specific Tasks: Double Tap and Swipe Up were preferred by roughly 80% of users for single-item transfers, while Pinch-To-Move was the clear favorite (75%) for tasks requiring multiple items or specific placement. Throw was favored for its speed by 42% of users but lacked precision.
Lessons learnt
Activities
Defining novel interaction technique
UI Design
Prototyping
Software development
Usability Testing
Evaluation
Tools
Sketch
Balsamiq
Invision
Eclipse for C# and Android development
Team
At first, participants thought swiping would be the easiest way to move data between devices. In fact, almost everyone we asked said so! But after trying it out, they changed their minds. It turns out, Pinch-to-Move was much better for moving lots of items at once or putting them in just the right spot. This shows that what people think they want isn't always what works best. It's really important to test out your ideas with real users to see what really helps them get things done.