Can-I-Park: Development Report - Assignment 5

Overview

Forget complicated parking signs. Can-I-Park is an augmented reality tool to help you understand parking signs. It is a mobile application that users use to scan parking signs.

It makes reading parking signs easy - explaining when you can park in a simple and easy to understand way for everyone.

Technical Development

Parking time slider increments

The parking time slider is set to change in increments depending on the current value. This helps the user select a rounded value more easily (eg. 2h 30m).

Scanning signs

In the current prototype only 6 pre-determined signs can be scanned using Vuforia engine. Each sign image target has been pre-configured with the signs allowed parking time, as well as any special conditions such as being a loading zone/accessible parking spot.

The scanned sign is then compared against the current device time, as well as the intended parking time to determine if the user can park. If they are able to park then the status target displayed next to the sign will be green to indicate the user can park, otherwise it is red indicating they cannot.

Global state management

There is a global script called scannerapp.cs that keeps track of the state of various functions in the app, keeping the user interface updated accordingly. 

On launching the app this script will go and find all the user interface elements in the interface, setting them to the correct value and state (after checking the device time and day etc.) and then awaits for further input.

3D Content

Low poly car

The low poly car below is displayed on the map to help illustrate to the user where their current car is located relative to the rest of the map.

Car by Poly by Google [CC-BY] (https://creativecommons.org/licenses/by/3.0/) via Poly Pizza (https://poly.pizza/m/75h3mi6uHuC)

Low poly sign

The low poly model of a sign is used on the map screen to show where the other parking signs are located relative to the user. 

Sign by Zsky [CC-BY] (https://creativecommons.org/licenses/by/3.0/) via Poly Pizza (https://poly.pizza/m/9UeVfOHm6k) 

Usability Testing

Our usability testing feedback consisted of both informal and formal feedback. Participants were recruited from within the KIT208/708 tutorial.

They are studying Information technology by bachelor or master in University of Tasmania. The formal feedback was undertaken by sitting down users to use our app in front of a set of predefined parking signs.

After a brief introduction to the purpose of the app, users were then instructed to tell us which signs they were allowed to park at.

We randomly selected two of participants to complete the testing without an explanation as to what the purpose of the app was. We then got these users to explain to us their understanding of how to use the app, as well as what they believed the purpose of the app was.

These two ‘thinking-aloud’ sessions showed that both users understood the app was to scan something. Ran (Rachlin 2015) stated that the approach of thinking-aloud can understand user’s thinking and barriers users can face.  Once users realised the parking sign images could be scanned, they immediately understood the app’s full purpose.

After their initial use, testers were asked to complete a range of tasks that they may have missed. These tasks can completely cover all functions on the application that find potential problems or drawbacks. Participants can perform these tasks in any order:

• Using camera to scan different parking signs
• Adjust the intended parking duration 
• Adjust time & day of the week in the debug interface
• View the map to see other parking spaces

Following using the app, we then had a discussion with the user (informal feedback), plus offered them a brief online survey to complete (formal feedback). The formal feedback consisted of both quantitative and qualitative feedback opportunities.

Participants were recruited from within a KIT208 tutorial for formal/informal testing. Additional informal testing was also conducted with various friends and family members of the team.

Quantitative feedback showed that most testers found the app intuitive and the scanning worked effectively without bugs in the prototype. Qualitative feedback offered some insights into how the app could be improved.

In addition to the likert scale questions there was a number of more free-form qualitative questions:

• Did you encounter any bugs whilst using the app?
• Was there anything you did not understand?
• How could the app be improved?

The full testing results can be viewed here: https://www.jotform.com/tables/222850582863866

The testing process and discussions helped us to understand the users' needs and expectations. Wynn and Maier (2022) demonstrated that feedback is necessary in the design and development process and feedback can be a catalyst that stimulates design and can lead to unwanted development complexity - but in this case it has helped to produce a more intuitive product.

Addressing the Results of the Usability Testing

Time slider

There were several comments about the slider used to set the intended parking time:

• “The slider to set the parking time whilst in a great spot, was also not immediately clear what that was for.”
•  improved?
• “Try slider increments… maybe like a log scale”

To address this the time slider was adjusted to work on a logarithmic-style scale, where the lower part of the slider allows for smaller increments than the later portion of the slider.

This is with the assumption that once users get past several hours, they are no longer as concerned with 5 minute increments and are more likely to increment in 15 minute blocks.

Hamburger menu (sidebar)

The hamburger icon to open the sidebar was moved to the top left of the app. This is in the position users expect, Apple suggests that you should “...let people hide and show the sidebar using the platform-specific interactions they already know.” (Apple Inc.)

The icon was also adjusted to use the list/hamburger icon from the Bootstrap Icons set, this was to help it be more familiar to users.

Low quality icons

Multiple users reported the icons appeared pixelated on the testing device. These icons were replaced with other icons from the Bootstrap Icon set and now appear at pixel perfect resolution.

Font

Whilst not mentioned directly in testing feedback, some informal comments stated the app interface didn’t feel like a native app. An aspect to help fix this was to adopt the Lato font family, a happy medium between the native Android font of Roboto and the iOS/MacOS font of San Francisco (SF) Pro.

References

Apple Inc. n.d. “Sidebars - Navigation and search - Components - Human Interface Guidelines - Design.” Apple Developer. Accessed October 27, 2022. https://developer.apple.com/design/human-interface-guidelines/components/navigation-and-search/sidebars.

Bootstrap. n.d. “Bootstrap Icons.” Bootstrap Icons · Official open source SVG icon library for Bootstrap. Accessed October 27, 2022. https://icons.getbootstrap.com/.

Dziedzic, Łukasz. n.d. “Lato.” Lato fonts - Lato. Accessed October 27, 2022. https://www.latofonts.com/lato-free-fonts/.

Rachlin, Ran. 2015. “'Thinking Aloud' Method In Usability Testing: Isn't As Good As It's Cracked Up To Be.” Ubertesters. https://ubertesters.com/blog/thinking-aloud-method-usability-testing-isnt-good-cracked/.

Wynn, D.C., Maier, A.M. Feedback systems in the design and development process. Res Eng Design 33, 273–306 (2022). https://doi.org/10.1007/s00163-022-00386-z