Model Human Processor
Perceive, understand, react.
Card, Moran and Newell present us with a human computer interaction model, coined the Model Human Processor. This model describes three processors with which humans perceive, process and react to external stimuli. First, the perceptive processor receives information from the world through the visual, auditory or tactile systems. The information is then processed by the cognitive processor to turn the stimulus into something we understand. The motor processor comes in last to execute the order that responds to the stimulus. All of this processing and acting upon stimuli takes time. You can only read so fast, you can only understand at a given rate and you can only move the mouse to a target and click it at a given rate.
While not every design project requires in-depth understanding of the model human processor, or any theory of cognition for that matter, it is important, at least, to have a basic understanding of information processing, including the structure of memory and how information is stored and retrieved.
Arguably, the most significant work in the field of Human Computer Interaction, to date.
The Seven Stages of the Action
Define intent, execute, evaluate.
Don Norman presents us, in his Design of Everyday Things, with the seven stages of the action. This model is not far from information retrieval models extensively studied in the classic IR field.
The seven stages of the action may be grouped into three higher level categories: define an objective, execute the action and evaluate the action.
Information retrieval
How people search.
Of course, the topic is worthy of an entire wikipedia of its own (all of the topics here are).
Questions I would like to explore:
- What triggers a search in the first place?
- Why are we constantly searching?
- Information needs: time based (sporadic vs. permanent) and type based (descriptive, conceptual, functional, procedural, explanatory)
- How do we formulate a search task based upon the tools made available to us? In a bookstore? A library? The web? Searching on TV with a remote control?
Orientation and Wayfinding
Knowing where we are.
We live in a 3d world. Some would argue there are more d’s, but that’s fine.
A basic requirement to feel comfortable is to know where we are. Put this way, it seems a trivial thing. Getting to that point, getting to «know where we are» is not as trivial as it may seem. It takes time and practice, it takes learning a number of things, often the hard way. The most crucial: landmarks. The second: connecting landmarks to build paths from point A to point B.
Do online maps consider this? They don’t even allow you to plot point B, or C or D. Research I conducted in this space clearly showed users begging (screaming) for this ability. The only way to do this nowadays is to use driving directions, which only allow you to do two points, not more.
The only mapping tool that gets it more or less right is Yahoo’s Maps Beta. I spoke with Paulien Strijland at CHI in 2006 (from Yahoo’s UE team) about their findings and mine and there were not many differences including how surprising it was for us to realize that users were not screaming for complex mapping features and services. Much to the contrary. Among others, we did find how important it is for people to plot multiple locations on a map, and to make comments on them, and to get driving directions changing the order of destinations, and printing and... one more thing: nobody ask for more advertising.
I talk about how I got to my design in the
Maps page.
The Magical Number Seven, Plus or Minus Two
This is the number of items we can store in memory for a given period of time. The time is generally milliseconds, and the items are referred to as ‘chunks’. Specifically, it refers to working memory. When we receive a set of chunks, and these could be sensory as well, not just verbal, we can retain the information for a given amount of time. After a short period of time, we begin to lose the ability to retain the information, a process called ‘decay.’ The are differences in time decay, based upon whether the information is verbal or sensory (e.g., auditory).
This finding is attributed to George Miller, who analyzed people‘s ability to retain information and presented his findings in 1956. However, research in this area has continued and new findings show that, while Miller’s conclusions remain accurate, working memory’s ability to retain information varies (somewhat) widely between populations and between data types.
Emotion
Connecting people.
I don’t think people like isolation. In certain instances it is even a form of punishment or even torture. We humans, on the other hand, like to pile up in cities to feel «involved», feel a part of the whole. Many products and services succeed without requiring the need for many people. [Under the assumption that technologies are there to deliver as expected] Products that succeed are mostly products that involve more than one individual somehow. This is not to say that certain activities done in isolation are worse in any way. The iPod, for instance, may very well be seen as a product used in isolation (arguably) and as of 1Q 2006 it holds around 70% of the portable music device market. Take email, for example. Besides cheap and faster than prior methods, it succeeds because it connects people. Chat rooms. Blogs. Cell phones, regular phones, the web even. Not gaming. Online gaming. Roller coasters are fun, but they are more fun if you go with family and friends. This was supposed to be a «future topic».
Trust
How do we build trust? What has to happen for you to trust a person? What about a computer? Would you trust a computer? Who would you listen to, your best friend or closest family member? Or would you, instead, follow a computer’s recommendation? This is, arguably, one of the most difficult aspects of any Personalization effort.