1. Overview of Information Processing laura leventhal

2.   Reference  Chapter 14

3. Why Information Processing We have looked at cognitive structures We have looked at cognitive structures I/OI/O memorymemory Now we will look at some facets of information processing Now we will look at some facets of information processing Problem-solvingProblem-solving Decision makingDecision making Formation of mental modelsFormation of mental models

4. Cognitive and Thinking Processes Just like a computer system, it is not enough to describe the input and output mechanisms and/or memory and storage. One also has to describe the information processes that utilize these facilities and these processes are thinking processes. Just like a computer system, it is not enough to describe the input and output mechanisms and/or memory and storage. One also has to describe the information processes that utilize these facilities and these processes are thinking processes.

5. What is thinking In his introductory Psychology text, Myers (1998) defines thinking as "…to think is to form concepts that organize our world, to solve problems, and to make efficient decisions and judgments…" In his introductory Psychology text, Myers (1998) defines thinking as "…to think is to form concepts that organize our world, to solve problems, and to make efficient decisions and judgments…" We focus on two aspects of thinking, problem solving and judgment and decision making. Problem solving and judgment and decision making are linked. One may make decisions in the context of solving a problem and one may solve a problem during decision making. For clarity we discuss them separately. We focus on two aspects of thinking, problem solving and judgment and decision making. Problem solving and judgment and decision making are linked. One may make decisions in the context of solving a problem and one may solve a problem during decision making. For clarity we discuss them separately.

6. Problem Solving Problem solving is typically defined as our ability, given a novel problem to develop a solution to the problem. Problem solving is typically defined as our ability, given a novel problem to develop a solution to the problem. Typical examples of problems include arithmetic problems, finding a route to a restaurant in a new city, writing a CHI textbook, writing a program. Typical examples of problems include arithmetic problems, finding a route to a restaurant in a new city, writing a CHI textbook, writing a program.

7. Designer Lesson – Problem Solving Recall that your user interface may be supporting problem solving. What can your interface do to aid in that process? Recall that your user interface may be supporting problem solving. What can your interface do to aid in that process? Both problem solving and using the interface require cognitive resources, such as memory. So reducing the cognitive resources required by your interface leaves more resources for problem solving. Both problem solving and using the interface require cognitive resources, such as memory. So reducing the cognitive resources required by your interface leaves more resources for problem solving. Recall that at the beginning of this chapter, we suggested that when we build an interface, we want to limit resources that users spend on operational tasks and encourage them to spend resources on functional tasks. Recall that at the beginning of this chapter, we suggested that when we build an interface, we want to limit resources that users spend on operational tasks and encourage them to spend resources on functional tasks. Interfaces with odd syntax, unpredictable behavior and so on steal cognitive resources from problem solving and donate them to interface operations. Interfaces with odd syntax, unpredictable behavior and so on steal cognitive resources from problem solving and donate them to interface operations.

8. Decision Making Decision making, or choosing among alternatives, is another thinking process that has significant implications for user interface design. Decision making, or choosing among alternatives, is another thinking process that has significant implications for user interface design. We like to believe that decision making is rational and logical, but lots of research indicates that it is not, in spite of any number of philosophical models to the contrary We like to believe that decision making is rational and logical, but lots of research indicates that it is not, in spite of any number of philosophical models to the contrary Research in this field indicates that they settle on a small number of hypotheses early on and tend to stay away from negative or disconfirmatory hypotheses. Research in this field indicates that they settle on a small number of hypotheses early on and tend to stay away from negative or disconfirmatory hypotheses. Usability Engineering Observation – Designers must be willing to believe disconfirmatory results from testing. Usability Engineering Observation – Designers must be willing to believe disconfirmatory results from testing.

9. Mental Models Models people have of themselves, others, the environment and the things with which they interact. Models people have of themselves, others, the environment and the things with which they interact. People form mental models through experience, training and instruction. People form mental models through experience, training and instruction. Models help us predict and explain interactions with the environment. Models help us predict and explain interactions with the environment. Models are often incomplete and inaccurate, yet people's behavior is a function of their models. Models are often incomplete and inaccurate, yet people's behavior is a function of their models.

10. Mental Models HCI facts HCI facts Use metaphors that help users develop reasonable models.Use metaphors that help users develop reasonable models. User models are often incomplete or partially incomplete. In response they may make bizarre predictions as to what to do next or use an alternative model.User models are often incomplete or partially incomplete. In response they may make bizarre predictions as to what to do next or use an alternative model. –Example 1: Novice internet users may think of www as a grid with North, South… –Example 2: Show Soloway overhead

11. Summary Stuff Some information processing operations are “hardwired” (eg.biases in decision making and reasoning) Some information processing operations are “hardwired” (eg.biases in decision making and reasoning) Some IP tasks are affected by expertise Some IP tasks are affected by expertise UI designers must accommodate both models. UI designers must accommodate both models. Show summary overheads Show summary overheads