Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
35 Cards in this Set
- Front
- Back
|
What is a System?
|
An entity that exists to carry out some purpose. it is composed of humans, machines, and things that work together/interact to accomplish some goal which these same components could not produce independently.
|
|
|
What is a Human-Machine System?
|
A combination of one or more humans and one or more physical components interacting to use inputs to get a desirable outcome.
|
|
|
What is a Manual System?
|
A manual system consists of hand tools and other aids coupled by a human operator who controls the operation. Operators of these systems use their own physical energy as the power source.
|
|
|
What is a Mechanical System?
|
A mechanical system consists of well integrated physical parts such as powered machine tools. They are designed to perform functions with little variance. Power is typically provided by the machine and the operator's function is essentially one of control, usually by the use of control devices.
|
|
|
What is an Automated System?
|
An automated system performs all functions with little or no human intervention. These systems still need human interaction and involvement.
|
|
|
What are 6 characteristics of systems?
|
Purposive, hierarchical, operate in an environment, components serve functions, components interact, and systems, subsystems, and components have inputs and outputs.
|
|
|
What is meant by "Systems are purposive"?
|
Every system must have a purpose, goal, or objective.
|
|
|
What is meant by "Systems are hierarchical"?
|
Some systems are parts of larger systems. There must be boundaries of systems and there must be a limit of resolution for the system ie. how far down into the system one is to go.
|
|
|
What is meant by "Systems operate in an environment"?
|
The environment of a system is everything outside its boundaries. Environments can impose constraints on a system or its behaviors.
|
|
|
What is meant by "Components of a system serve functions"?
|
Components are the lowest level of analysis in a function and help fulfill the system goals. They can be sensing (information receiving from an outside system), information storage (information is coded on tapes, disks, templates, records), information processing and decision (embrace various types of operations performed with information that is sensed, stored, and results in an action), or action functions (consequences of the decisions made).
|
|
|
What are two types of action functions in a system?
|
Physical control actions activate certain control mechanisms or handle materials and objects.
Communication actions signal or record other methods. |
|
|
What is meant by "Components of a system interact"?
|
Components work together to achieve system goals.
|
|
|
What is meant by "Systems, subsystems, and components have inputs and outputs"?
|
Through inputs and outputs all the pieces of a system interact and communicate.
|
|
|
What is a closed loop system?
|
The system performs some process which requires continuous control (eq. vehicular operation) and requires continuous feedback for success.
|
|
|
What is an open loop system?
|
When the system is activated it needs no further control, or can't be further controlled (eg. firing a rocket without a guidance system).
|
|
|
What is system reliability?
|
The probability of successful performance.
If a system contains more than one component the reliability of the system is based on the reliability of those components (series, parallel, or combination). |
|
|
What are components in series (of a system)?
|
Success of the total system depends on successful performance of each and every component. As components increase, reliability decreases. The maximum reliability in a system is equal to the least reliable component.
|
|
|
What are components in parallel (of a system)?
|
Two or more components perform the same function. This can be referred to as backup or redundancy arrangements. Adding parallel components increases reliability of the system.
|
|
|
What is a descriptive study?
|
Characterizes a population in terms of certain attributes and create basic data upon which many design decisions are based. It assesses the magnitude and scope of a problem.
|
|
|
What are criterion variables?
|
Describe those characteristics and behaviors of interest in the study. Physical characteristics (reach, weight), performance data (reaction time), subjective data (opinions), physiologically induced data (heart rate, temperature)
|
|
|
What are stratification variables?
|
(surveys)
Proportionally representative of a population. They predict a general response. |
|
|
What is the difference between representative samples and random samples
|
Representative samples are representative of a population and relevant.
Random samples mean each member of the population has an equal chance of being selected. |
|
|
What is experimental research?
|
Tests the effects of some variable on behavior (eg. testing effects of seatbelts on functional arm reach). The concern is whether a variable has an effect on behavior and the direction of that effect.
|
|
|
What is the difference between an independent and dependent variable?
|
Independent variables are the variables being manipulated (task related, environmental, subject related).
Dependent variables are behaviors being measured to assess the effect of the independent variables. |
|
|
What is evaluation research?
|
The purpose of evaluation research is to assess the effect of something, which is a system or product. It seeks to describe the performance and behaviors of people using systems or products.
|
|
|
What are criterion measures in research?
|
Characteristics and behaviors measured in descriptive studies. The dependent variable in experimental research, the basis for judging goodness of design in an evaluation.
|
|
|
What are three types of criterion measures in research?
|
System descriptive criteria (reflect engineering aspects of a system)
Task performance criteria (outcome of a task quality, quantity, and performance) Human criteria (behaviors and responses during task performance, measured in physiological indices and subjective indices) |
|
|
What is face validity?
|
The extent to which a measure looks as though it measures what is intended
|
|
|
What is content validity?
|
The extent to which a measure of some variable samples a domain, such as field of knowledge or a set of behaviors
|
|
|
What is construct validity?
|
The extent to which a measure is really tapping the underlying construct of interest.
|
|
|
What is reliability?
|
An explanation of how errors are produced; the probability of successful performance of a task or element of a task.
|
|
|
What is information theory?
|
An operational definition of the term information and a method for measuring it.
|
|
|
What is the smallest amount of information required to decide between two equally likely alternatives?
|
a "bit"
|
|
|
What is bandwidth?
|
The rate of information transmission over a channel, measured in bits per second.
|
|
|
What is the Hick Hyman law?
|
The reaction time to a stimulus increases as the number of equally likely alternatives increases. Choice reaction time is a linear function of stimulus information.
(Reaction time is slower or longer as the number of action choices increase) |
