Human Factors Engineering - Test 2

Displays

a presentation of visual information

Device Displays

computer monitor, tablet screen

Signs

street, navigational, safety

Equipment Displays

vehicle dashboard, machine motor

Quantitative

when the exact number is important; con: takes longer to read

Qualitative

commonly used; shows values within a range; con: won’t know actual value

Monitoring Tasks

setting, watching, tracking

Three Principles to Monitoring

legibility, analog over digital, analog form and direction

Display Layout

deciding where to put things; lookout for primary visual area, importance of use, organization, etc.

Labeling

signals the identity or function of a display; presented as icons or text

Heads Up Display (HUD)

information on top of primary visual area; not widely used anymore because too cluttered

Multiple Displays

primary monitor directly in front of user

User Interface

boundary between human and the machine

Purpose of Controls

transmit information to some device, mechanism, or system

Discrete Controls

limited number of conditions (on/off, high/med/low, 1/2/3)

Continuous Controls

unbroken scale for conditions (speed, volume, pressure)

Ease of Identification

primarily a coding problem; finding correct control for correct system behavior

Keys and Pushbuttons

non-round and concave on top; provide feedback to operator

Knobs

used to apply torque; circular

Control Response Ratio

how much movement of a control is necessary

Resistance

purpose to avoid inadvertent activation of the control

Dead Space

amount of control movement around the null position

Hick-Hyman Law

how difficult it is to select correct control when given too many options

User Conventions

on = up, forward, right; off = down, rearward, left

Lab 5

Identifying different types of displays and controls

Lab 5

Explaining good and bad decisions made for products

Human Computer Interaction (HCI)

the relationship between human factors and computers

Poorly Designed Computer Interface?

decrease in performance, increase in errors

Usability

efficiency, accuracy, learnability, memorability, satisfaction

User Characteristics

balance between functionality and ease of use; how many functions do we show users

7 Stages of Action Model

how users try to connect with a system

Design Principles

consistency, match to real world, show system status, minimize memory requirement

Screen Design

incorporates user input and computer output

Menus

preferred when users have to search

Fill-In Forms

replacing something once done on paper

Function Keys

best for expert users

Direct Manipulation

if we know what user is trying to do

Evaluating Designs

usability heuristics and user testing

Usability Metrics

effectiveness, efficiency, satisfaction

Effectiveness

completion, success, features used

Efficiency

time, learning, errors

Satisfaction

subjective scales, frustration

User Experience

users interaction with a product

Lab 6

Using the Heuristic Data Table to logically evaluate the use of a specific product or feature

Lab 6

Using the User Testing Data Table to determine the importance of use of a product or feature by having humans test them out and give feedback

Automation

when a computer or machine performs a task otherwise done by a human

Sheridan Levels of Automation

a scale from low to high on the different types of automation there is going from human in complete control to machine ignores the human

Automation Stages

information acquisition and selection; information integration; action selection and choice; control and action execution

Problems with Automation

reliability? “dumb and dutiful”? act unexpectedly?

Trust

operator should put trust in automation directly proportionate to its reliability

Mistrust vs Overtrust

on one end there is having a lack of trust and the other is having too much trust; want something somewhere in between both

MABA-MABA

a list to help decide which tasks humans and automations will do

Humans are Better At…

small signals, patterns, reasoning, improvising

Machines are Better At…

monitoring, repeating, multitasking

Human-Centered Automation

having auto features but will allow for human to step in if needed

Human-in-the-Loop

if machine needs more info it will ask human for help

Error

inappropriate human behavior that lowers levels of system effectiveness or safety

Omission

fails to do something that should have been done

Commission

does something that should not have been done

Sequence

incorrect ordering

Mistake

the action was intentional but inappropriate

Slip

the action was not intended

Lapse

an omission slip

Violation

intentional error

System Approach to Errors

errors are consequences not causes

Swiss Cheese Model

all areas must align for a bad outcome to occur

Domino Theory

five factors lead up to an accident; only one “domino” has to be taken away to make sure it doesn’t happen

Human Factors Analysis and Classification System (HFACS)

helps identify a system level reason for why someone performs unsafe acts

Human Reliability Analysis (HRA)

task analysis is used to describe and understand the human interactions with the system

Deming’s View of Human Behavior

“The workers are handicapped by the system, and the system belongs to the management.”

Technique for Human Error Rate Prediction (THERP)

flowchart of options to navigate the database and determine where the bad outcomes are

THERP Strength

well suited to proceduralized, structured assessments

THERP Weakness

not adaptive; limited error reduction

THERP Models are…

binary decision models where task is done either correctly or incorrectly

Training

acquisition of knowledge, skills, and competencies as a result of teaching

Training Goals

shortest amount of time; longest retention; cost effective; is enjoyable

Learning Curves to Training

with an increase in practice comes less time and errors

Factors Influencing Retention

characteristics of the task, degree of original learning, instructional strategies

Context-Dependent Memory

learning how to do something one way and expecting it to work in other situations as well

Transfer of Training

previous learnings apply to a new situation

Strategies to Maximize Transfer

training support, task simplification, part task training, feedback, practice

Internal Factors that Impact Behavior

past experience, personality, agenda

External Factors that Impact Behavior

social setting, organizational setting

Psychosocial Risk Factors

a person’s work surroundings can influence their behavior

Examples of Psychosocial Factors

work demands and mental load, co

Groups

people who have very similar jobs working together (welders working together)

Team

people who have different jobs working together to complete a goal (House Renovation Team)

Groups vs Teams

groups have similar jobs, individual output, and low coordination while teams have different jobs, collective output, and high coordination

Best Individual Performance >

group performance

Group Performance >

avg individual performance

Team Training

successful training exercises to improve team effectiveness

Lab 8

Simulating two types of employee training; traditional and real