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Plan : 1. Input–output channels 2. Human memory 3. Thinking: reasoning and problem solving 4. Emotion 5. Individual differences 6. Psychology and the design of interactive systems 2

A person’s interaction with the outside world occurs through information being received and sent: input and output. In an interaction with a computer the user receives information that is output by the computer, and responds by providing input to the computer. the user’s output becomes the computer’s input and vice versa. 1. INPUT–OUTPUT CHANNELS 3

Input in the human occurs mainly through the senses and output through the motor control of the effectors. There are five major senses: sight, hearing, touch, taste and smell. Of these, the first three are the most important to HCI. Taste and smell do not currently play a significant role in HCI 1. INPUT–OUTPUT CHANNELS 4

Similarly there are a number of effectors, including the limbs, fingers, eyes, head and vocal system. In the interaction with the computer, the fingers play the primary role, through typing or mouse control, with some use of voice, and eye, head and body position. 1. INPUT–OUTPUT CHANNELS 5

1. Vision : Human vision is a highly complex activity with a range of physical and perceptual limitations, yet it is the primary source of information for the average person. Vision begins with light. The eye is a mechanism for receiving light and transforming it into electrical energy. Light is reflected from objects in the world and their image is focused upside down on the back of the eye. The receptors in the eye transform it into electrical signals which are passed to the brain. INPUT–OUTPUT CHANNELS 6

2. Hearing : The sense of hearing is often considered secondary to sight, but we tend to underestimate the amount of information that we receive through our ears. The auditory system can convey a lot of information about our environment. It begins with vibrations in the air or sound waves. The ear receives these vibrations and transmits them, through various stages, to the auditory nerves. INPUT–OUTPUT CHANNELS 7

The auditory system performs some filtering of the sounds received, allowing us to ignore background noise and concentrate on important information. We are selective in our hearing. INPUT–OUTPUT CHANNELS 8

3. Touch : The third and last of the senses that we will consider is touch. Although this sense is often viewed as less important than sight or hearing, we can’t imagine life without it. Touch provides us with vital information about our environment. The apparatus of touch differs from that of sight and hearing in that it is not localized. 1. INPUT–OUTPUT CHANNELS 9

We receive stimuli through the skin. The skin contains three types of sensory receptor:  thermoreceptors respond to heat and cold,  nociceptors respond to intense pressure, heat and pain.  mechanoreceptors respond to pressure. It is the last of these that we are concerned with in relation to human–computer interaction. 1. INPUT–OUTPUT CHANNELS 10

Memory refers to the processes that are used to acquire, store, retain and later retrieve information. There are three major processes involved in memory: encoding, storage, and retrieval. 2. HUMAN MEMORY 11

In order to form new memories, information must be changed into a usable form, which occurs through the process known as encoding. Once information has been successfully encoded, it must be stored in memory for later use. The retrieval process allows us to bring stored memories into conscious awareness. 2. HUMAN MEMORY 12

there are three types of memory or memory function: 2. HUMAN MEMORY Sensory Memory Short-Term memory Long-Term memory Human memory 13

1. Sensory Memory : 1. Sensory Memory : Sensory memory is the earliest stage of memory. During this stage, sensory information from the environment is stored for a very brief period of time, generally for no longer than a half-second for visual information and 3 or 4 seconds for auditory information. 2.HUMAN MEMORY 14

2. Short-Time Memory : Short-time memory, also known as active memory, is the information we are currently aware of or thinking about. Most of the information stored in active memory will be kept for approximately 20 to 30 seconds. 2. HUMAN MEMORY 15

3. Long-Time Memory : Long-time memory is intended for the long-term storage of information. Here we store factual information, experiential knowledge, procedural rules of behavior…. in fact, everything that we ‘know’. 2. HUMAN MEMORY 16

Some of this information is fairly easy to recall, while other memories are much more difficult to access. the information can remain in long term memory indefinitely. 2. HUMAN MEMORY 17

Thinking can require different amounts of knowledge. Some thinking activities are very directed and the knowledge required is constrained. Others require vast amounts of knowledge from different domains. There are two categories of thinking:  Reasoning  Problem solving. 3. THINKING: REASONING AND PROBLEM SOLVING 18

1. Reasoning : Reasoning is the capacity for a person to make sense of things to establish & verify facts, To rationally work through data, information, facts, and beliefs. It is the process of forming conclusions and judgments from facts or premises. There are two main types of reasoning:  Deductive reasoning  Inductive reasoning 3. THINKING: REASONING AND PROBLEM SOLVING 19

We use each of these types of reasoning in everyday life, but they differ in significant ways.  Deductive reasoning: Deductive reasoning derives the logically necessary conclusion from the given premises. For example, 3. THINKING: REASONING AND PROBLEM SOLVING If it is Friday then she will go to work It is Friday Therefore she will go to work. 20

 inductive reasoning: Inductive reasoning uses analogies, examples, observations, and experiences to form conclusive propositions. For example: 3. THINKING: REASONING AND PROBLEM SOLVING if every elephant we have ever seen has a trunk, we infer that all elephants have trunks 21

2. Problem solving: If reasoning is a means of inferring new information from what is already known, problem solving is the process of finding a solution to an unfamiliar task, using the knowledge we have. Human problem solving is characterized by the ability to adapt the information we have to deal with new situations. 3. THINKING: REASONING AND PROBLEM SOLVING 22

There are a number of different views of how people solve problems:  Gestalt theory : Max Wertheimer considered thinking to happen in two ways: productive and reproductive. Productive thinking is a quick insightful unplanned response to situations and environmental interaction. Reproductive thinking is solving a problem with previous experiences and what is already known. 3. THINKING: REASONING AND PROBLEM SOLVING 23

 Problem space theory : In this theory, people solve problems by searching in a problem space. The problem space consists of the initial (current) state, the goal state, and all possible states in between. The actions that people take in order to move from one state to another are known as operators. 3. THINKING: REASONING AND PROBLEM SOLVING 24

Our emotional response to situations affects how we perform. For example, positive emotions enable us to think more creatively, to solve complex problems, whereas negative emotion pushes us into narrow, focussed thinking. A problem that may be easy to solve when we are relaxed, will become difficult if we are frustrated or afraid. 4. EMOTION 25

All the points that we discussed apply to the majority of people. Not with standing this, we should remember that, although we share processes in common, humans, and therefore users, are not all the same. We should be aware of individual differences so that we can account for them as far as possible within our designs. 5. INDIVIDUAL DIFFERENCES 26

These differences may be long term, such as sex, physical capabilities and intellectual capabilities. Others are shorter term and include the effect of stress or fatigue on the user. Still others change through time, such as age. 5. INDIVIDUAL DIFFERENCES 27

Interaction at the interface is largely a cognitive process For effective design can apply knowledge of cognitive psychology Need to understand which aspects are important & relevant to interface design Can provide information about what the user can and cannot do Help explain why uses experience problems with particular interaction /design aspects Must remember computers are not used in isolation 5. PSYCHOLOGY AND THE DESIGN OF INTERACTIVE SYSTEMS 28

Principles and results from research in psychology have been distilled into guidelines for design (( المبادئ التوجيهية, models to support design (( نماذج لدعم تصميم and techniques for evaluating design (( تقنيات لتقييم التصميم. 5. PSYCHOLOGY AND THE DESIGN OF INTERACTIVE SYSTEMS 29