Information

Information & Interaction Design

Mick McQuaid

mcq@utexas.edu

University of Texas at Austin

20 Oct 2025

Week NINE

Information

Information Overload

Information itself

Information Structure
- Unstructured Information
- Semi-structured Information
- Structured Information (relational, hierarchical, networked)

Information Concepts (Big data, Memes)

Organizing Information (labeling, card sorting, evaluating schemes)

Information Design Patterns

Information Overload

An old concept

Passing the basketball illustrates attentional blindness

London map experiment illustrates the same principle

Terms like cognitive overload, change blindness are related

People studied information overload long before the Internet made it a tired phrase. In psychology classes you may have seen videos of famous experiments such as passing the basketball. In this experiment, a person watches a group of people passing basketballs and is asked to count the number of total passes and keep them in mind. The person is told that accuracy is very important. The real purpose of the basketball passing is to overload the person with information. Meanwhile, a person wearing a gorilla costume walks through the room. After the exercise, the researchers ask the person if anything unusual happened. The person invariably replies that nothing unusual has happened. The researchers then show the person a video of the preceding few minutes, including the person in the gorilla costume. Invariably the person is shocked. The person almost never accepts that someone in a gorilla costume walked in front of them until they see the video evidence. This demonstrates the astounding power of information overload to shut down our perceptions of our environment.

Similar experiments abound. There is, for instance, one experiment where a researcher with a map in hand walks up to someone on a crowded London sidewalk and asks for directions. While the bystander tries to think of the best route, two uniformed workmen walk between the researcher and the bystander, carrying a large heavy mirror. Concealed behind the mirror is another researcher of a different race and sex but carrying an identical map in the same folded orientation. The original researcher moves along with the two workmen who speed past so that there is only a moment when the bystander can’t see the researcher. The new researcher, of a different race and sex, tries to carry on the same line of questioning as if nothing had happened. Video of the encounters suggests that the bystander usually does not realize the change because of the information overload resulting from trying to visualize the landmark under discussion and the route information.

Both these experiments and similar ones are described online under information overload or cognitive overload or related terms such as change blindness or selective attention.

Information itself

Information theory (Shannon (1948), Cover and Thomas (2006))

Information architecture (Rosenfeld, Morville, and Arango (2015))

Information Design (Redish (2014))

In addition to studying the effects of information, there are many scientists studying information itself and the characteristics that define information and distinguish one kind of information from another.

Following is one approach to examining information. There are others. Notable examples include Information Theory, first promulgated by Shannon (1948) and typically introduced to students via Cover and Thomas (2006). This introductory textbook describes entropy, data compression, channel capacity, rate distortion, and multi-user theory. It has applications in communicatons, statistics, complexity theory, and investment. A second example is the view popularly called Information Architecture, espoused in Rosenfeld, Morville, and Arango (2015). This view is mostly concerned with the organization of large websites. A third example is similar but is often called Information Design, and is espoused by Redish (2014) and is concerned mostly with the organization of text on websites. I (Mick) have chosen a set of topics that seem relevant to HCI specialists and have little overlap with the above-mentioned texts, so I refer the diligent reader to those texts for different perspectives.

Unstructured information

Term “unstructured” may be misleading

There is structure but it is unlabeled

Examples include news articles and blog posts

“Unstructured” is a matter of degree and is best understood by comparing it to semistructured and structured information

The term unstructured information may be a bit misleading. It typically refers to information that is indeed structured but whose content does not follow very strict rules.

For example, a news article or a blog post could be considered unstructured information. An article usually has a title but not always. It does not follow a strict rule as to whether or not it is titled or subtitled. It may or may not have pictures. It may have varying numbers of paragraphs, tables, diagrams, comments from users, links to related articles, or other features. It may have a listed author or not. The key is that it is completely flexible about these things and the person who presents the article does not have to think about conveying the structure of the article to a computer program, only to a human reader. Human readers are much more forgiving of lapses in structure than are traditional computer programs.

This lack of structure is really a matter of degree and is best understood by comparing it to the following terms.

Semistructured information

Labeled information, e.g., forms filled out by people

There are rules, but it’s often easy to break them

Hence, human intervention is required to deal with rule breakage

Semistructured information refers to labeled information such as is found in forms filled out by people. When you fill out a form, each place where you can insert information contains a label telling you what kind of information belongs there. There are some rules but it is often quite easy to break rules for completing forms.

Some forms enforce rules by not allowing you to type in any information that violates the rules. A good example of this can be found in income tax forms online.

Yet most online forms allow the person filling them in some flexibility and may contain instructions that can be disobeyed. For instance, you may be transgendered and asked to fill in M or F in a box marked gender. You may be able to enter a T or leave the box blank, depending on how much time and money was spent on developing the form. If you do enter something unexpected, the person or program processing the form has to decide how to handle it.

It is a hallmark of semistructured information that some human intervention is required to process it because some entered information can not be anticipated.

Structured information

Obeys strict rules

Can be processed rapidly in large volumes

Can be easily aggregated to tell, for instance, how many orange shirts size L were ordered on game days in the 2021 season

Often passed from one traditional computer program to another

Uses techniques to diminish the effect of human error, such as bar code readers

Usually presented as relations (tables with rows and columns) or hierarchies (trees)

Structured information obeys strict rules and can be processed rapidly in large volumes and can be aggregated easily to determine, for instance, how many orange shirts in size L were ordered on game days in the 2021 season. Structured information is often passed from one traditional computer program to another. Systems that process structured information use various techniques to diminish the effects of human error, including bar code readers, credit card readers, qr code readers, nfc readers and similar devices to obtain information. When human input is needed, it is often restricted. For instance, when a fast-food cashier takes an order, they often press a touchscreen area with a picture of the item being ordered rather than trying to type a name or a price, both of which are supplied by a computer program reading the touchscreen.

Most structured information in and between large organizations is presented in one of two main ways, as relations or as hierarchies. There is also networked information, but we’ll consider that later.