Chapter 2: Understanding and conceptualizing interaction Question 1

Understanding the problem space –What do you want to create? –What are your assumptions? –What are your claims? Right – In science it’s usually much easier to define the “problem space” you are working in. In ID, however, understanding “the problem” takes as much time as solving it!

A framework for analyzing the problem space Are there problems with an existing product or user experience? Why do you think there are problems? How do you think your proposed design ideas might overcome these? When designing for a new user experience how will the proposed design extend or change current ways of doing things? Problem: How to help students have a green dorm room? Step 1: How do they try to solve that problem now?

Conceptual model “a high-level description of how a system is organized and operates.” (Johnson and Henderson, 2002, p. 26) Question 2

Main components Metaphors and Analogies. Concepts Relationships Concept  User Experience Goals.

Benefits How do users understand the interaction model? Not to become narrowly focused early on Establish a set of common terms they all understand and agree upon Reduce the chance of misunderstandings and confusion arising later on

A classic conceptual model: the spreadsheet

The Star interface

Interface metaphors Designed to be similar to a physical entity but also has own properties –e.g. desktop metaphor, search engine Question 3

Benefits of interface metaphors Makes learning new systems easier Helps users understand the underlying conceptual model

Problems with interface metaphors (Nelson, 1990) Break conventional and cultural rules –e.g., recycle bin placed on desktop Can constrain designers in the way they conceptualize a problem space Conflict with design principles Forces users to only understand the system in terms of the metaphor Designers can inadvertently use bad existing designs and transfer the bad parts over

Interaction types Instructing Conversing Manipulating Exploring Right – Good old GNU Emacs – what type is this?

Instructing Where users instruct a system by telling it what to do –e.g., tell the time, print a file, find a photo Very common interaction type underlying a range of devices and systems Question 4 Right - The prototypical Instructing interface – The Linux terminal.

Conversing Like having a conversation with another human Examples include search engines, advice-giving systems and help systems Also included, of course, is having a real conversation with another human, like texting! Question 5 Right – Typical start of a help session in an application.

Manipulating Exploit’s users’ knowledge of how they move and manipulate in the physical world Virtual objects can be manipulated by moving, selecting, opening, and closing them

Direct manipulation Proposes that digital objects be designed so they can be interacted with analogous to how physical objects are manipulated Right – DM in action. The perfectly intuitive interface?

Core principles of DM Continuous representation of objects and actions of interest Physical actions and button pressing instead of issuing commands with complex syntax Rapid reversible actions with immediate feedback on object of interest

Why are DM interfaces so enjoyable? Novices can learn the basic functionality quickly Experienced users can work extremely rapidly to carry out a wide range of tasks, even defining new functions Intermittent users can retain operational concepts over time Error messages rarely needed Immediate feedback Users gain confidence and mastery and feel in control

What are the disadvantages with DM? Not all tasks can be described by objects and not all actions can be done directly Some tasks are better achieved through delegating rather than manipulating –e.g., spell checking Moving a mouse around the screen can be slower than pressing function keys to do same actions

Exploring Involves users moving through virtual or physical environments Question 6

A virtual world

Extra Credit Take a look at and write a review of the proposed mode of interaction. Please turn in a.pdf file by 11:59 PM Friday. Angel – Lessons – Drop Boxes - Extra Credit –Week 9. Question 7

Let’s inspect your project As a team look at your use cases: What is the ideal interaction type to accomplish each use case? –Instructing –Conversing –Manipulating –Exploring

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