SmartView

Ergonomically designed kitchen scale.

The SmartView project is an ergonomic redesign of the standard electronic kitchen scale intended to increase the comfort and functionality of a ubiquitous yet often overlooked appliance. The physical device has been updated to include increased adjustability. Offloading the display and recipe tracking features to the included companion app allows users to take advantage of their smartphone's full suite of accessibility tools. The app will enable users to store and view their favorite recipes and follow step-by-step instructions updated in real time according to how much each ingredient weighs on the scale. 

The scale and app are connected via Bluetooth so that the ingredient weights can be displayed directly within the mobile application. While working, users can place their phone into the adjustable stand incorporated so that the recipes are clear as they work, reducing the need to move around the kitchen. This cellphone stand features a self-supporting hinge allowing users to view their screen at the most comfortable angle for their height and kitchen layout. A telescoping mechanism has horizontal adjustability to accommodate a wide range of mixing bowls and containers without obscuring the display while reducing the device's footprint for more convenient storage when not in use.

Contextual Inquiry

We began by observing volunteers of various skill levels in their homes while performing multiple baking and cooking projects using kitchen mixers and scales. We documented our users' storage, setup, use, and cleaning of the appliances. While they worked, we took detailed notes of their order of operations, mistakes, comments, and non-verbal reactions throughout the session. After each observation, we interviewed the user to learn more about their motivations, opinions, and perceptions of their kitchen scales.

Key Takeaways:

  • Most users employ a smartphone or tablet to display recipes while cooking.

  • Users return to their phones or tablet to double-check figures more often than they realize.

  • The LCD displays on most scales have low contrast and can be difficult to read under certain lighting conditions.

  • The mixing bowls and other containers often obstruct the display and controls, forcing users to stoop or crane their necks.

  • Storage space is consistently noted as a primary concern when selecting appliances.

A typical user’s baking experience

Prototyping and Testing

The testing equipment included a non-functional full-scale prototype constructed of MDF, an iPhone with simulated screen images, assorted mixing bowls, and dry goods, including flour, lentils, and pasta. This usability testing aimed to evaluate the interaction between the user interface screen and the physical prototype, see if the user could quickly and smoothly adjust the phone’s screen using the hinge mechanism and if they would opt to make horizontal adjustments.

We asked participants to weigh ingredients for a mock recipe. We verbally relayed the simulated recipe steps and weights that would appear on the interface screen to the user. After completing several measurements, we told the user they had completed the recipe and observed if and how they cleaned the scale before putting it away. 

With the mock measurements completed, we retrieved the scale, and if the user had not adjusted the screen during the test, we asked them to show us how they would have positioned the screen if they had known that it was adjustable. We then asked the user to place the screen at its optimal viewing position and recorded the angle. We also asked them to set the screen at its highest acceptable viewing position and recorded that angle. 

Results:

  • 40% of users failed to recognize the horizontal adjustment feature without instruction.

  • 17% of users were unable to adjust the screen angle without instruction.

  • Preferred screen angles ranged from 18° to 70°.

  • The maximum acceptable screen angle reported was 90°.

Design Implications:

  • Adjustability needs to be made obvious in the physical design.

  • The grip width for the handle should be at least 24 mm to accommodate the ability of the 95th percentile man to fit their thumb on the handle's grip comfortably.

  • The screen hinge should be self-supporting.

  • The range of potential screen positions should include angles 0° to 90°.

Revised Design

Updates:

  • The telescoping mechanism reduces footprint for ease of storage.

  • Textured grip and integrated handle for ease of horizontal adjustability.

  • The position of the phone stand and integrated handle visually indicates adjustability.

  • Bluetooth connection leverages the phone’s display settings and accessibility features.

  • Eliminating integral screens reduces weight, manufacturing complexity, and expense.