This lecture note and the next one 7. Models for Interface Design are a bit different in their flavor compared to the previous lecture notes. Instead of focusing on the user-centered design process, we discuss a more theoretic side of user interface and interaction design, an area of computer science that is often referred as Human-Computer Interaction (HCI). Though not directly related, knowing theoretical underpinning of user interface and interaction design could be useful in yielding and selecting ideas for your system's design. You can mobilize heuristics, empirical evidence, and theoretical knowledge.
In this module, we learn basic terminologies and theories around input methods—particularly text entry and pointing. The concepts and vocabularies would you learn here could help you understand and discuss the user interface's quality in error prevention, learnability, the efficiency of use, etc.
A user commonly gives input instruction to a system with the intent of text entry and pointing. A channel of input (and output) between a user and a computer is called a modality (Karray et al., 2008). For text entry, interaction modalities include interface and interaction methods like physical keystrokes and speech (Karray et al., 2008; Preece et al., 2015). Pointing devices include mice, trackball, joystick, pointing stick, stylus, and so on.
[Put that there. Source: https://youtu.be/RyBEUyEtxQo](https://www.youtube.com/watch?v=RyBEUyEtxQo)
Put that there. Source: https://youtu.be/RyBEUyEtxQo
A system that utilizes a single communication channel is called unimodal, whereas a system that uses multiple modalities is called multimodal (Bouchet et al., 2004). See the video example of a multi-modal interaction.
[Keyboards & Command Line Interfaces: Crash Course Computer Science #22. Source: https://youtu.be/4RPtJ9UyHS0](https://youtu.be/4RPtJ9UyHS0)
Keyboards & Command Line Interfaces: Crash Course Computer Science #22. Source: https://youtu.be/4RPtJ9UyHS0
Text entry is a fundamental part of giving input to a computer. And the keyboard has been the dominant device for text input. The most widely used keyboard layout is QWERTY, which was patented by Sholes and his partner James Densmore in 1878. While it is very popular, the QWERTY keyboard suffers from some limitations, such as necessitating awkward finger motions (e.g., requiring a user to type some commonly used terms like "was" and "were" using one hand), which reduce the efficiency of input. Alternative keyboard layouts that claimed to be more efficient were invented, including the Dvorak keyboard patented in 1936. There are dedicated Dvorak users today and they claim the Dvorak keyboard offer faster typing speed. But they remain a minority compared to QWERTY keyboard users. QWERTY is "efficient enough" and "familiar enough" for typical users, which hinder the adoption of alternative keyboard layouts. This is a demonstration of power law of practice.
ShapeWriter
Swype
Mobile text entry methods changed over time as the mobile device's market trend evolved in the last few decades. Feature phones that dominated the industry supported keypad-based text entry. While personal digital assistants (PDA, a more feature-rich "smart" phone) like BlackBerry and [Palm](https://en.wikipedia.org/wiki/Palm,_Inc.) with richer text-entry methods gained popularity, it was a minority. It was the introduction of iPhone and Android-based smartphones that changed the landscape of mobile text entry. These devices are pervasive today. Smartphone's touch screen—a surface area that juxtaposes touch input plane and display—enables various input methods, like:
Speech recognition is becoming one of the mainstream text-input modalities. While the accuracy of the input method is still flaky, it has advantages over typing-based input. It has a higher input speed (Hauptmann and Rudnicky, 1990); while ordinary people's typing speed ranges around 30 words-per-minute (wpm), a speech recognition system can dictate speech at a rate faster than 100 wpm. And its typing-free nature allows designers to play with novel form factors that do not have a dedicated typing region, like watch devices (e.g., Apple Watch) and smart speakers (e.g., Amazon Echo, Google Home). But speech-based input suffers from some challenges like: