Industrial Ergonomics unit VII

BOS 3701, Industrial Ergonomics 1

UNIT VII STUDY GUIDE Information Ergonomics, Controls, Displays, Warning Labels, Instructions, and Product Liability

Course Learning Outcomes for Unit VII Upon completion of this unit, students should be able to:

1. Discuss information processing. 2. Discuss the general guidelines for controls and displays. 3. Explain the emergency control design. 4. Explain the guidelines for color coding in displays. 5. Discuss product liability. 6. Evaluate the general principles for design of warning

Unit Lesson This unit focuses on information ergonomics, controls, displays, warning labels, instructions, and product liability. The first chapter introduces information processing, measurement of mental workload, and ergonomic design of controls and displays. Factors that affect information processing include a person's experience, knowledge, mental agility, and the ability to generate new ideas. The interaction between a human and a machine relies on the information exchanged between the human and the machine. Information can be defined as the absorption of interpreted data through human sensory functions. The basic components of information processing models are sensory receipt, short-term memory, long-term memory, response, and reaction. The most primitive form of perception is detection, which simply involves knowing whether a signal is present or not. Signal detection theory is used to evaluate perception when there are two possible states. For example, an audible symbol is either detectable or not. In signal detection analyses, an operator is asked to state whether or not a signal was detected. Four possible outcomes are below:

1. Hit - saying there is a signal when there is a signal 2. False alarm - saying there is a signal when there is no signal 3. Miss - saying there is no signal when there is a signal 4. Correct rejection - saying there is no signal when there is no signal

There are numerous theories of information processing, and the flow of information is shown in Figure 9.2 in the textbook. The two general categories of information processing theories are serial and parallel models. Serial models describe information processing as a set of discrete sequential stages. Parallel models view information processing as occurring simultaneously through multiple interactions across the brain's neural network. The human memory can be categorized into three aspects: sensory storage, short-term memory, and long-term memory. The visual storage lasts for less than one second before fading away, while the auditory storage lasts for a few seconds before it disappears. Short-term memory is associated with a temporary storage of information which is briefly retained in the brain. The three main activities related to long-term memory are storage, deletion, and retrieval. Information is transferred from short-term memory to long-term memory by semantically coding it. The two categories of retrieval are recall and recognition. Physiological

Reading Assignment Chapter 9: Information Ergonomics, Controls, and Displays Chapter 10: Warning Labels, Instructions, and Product Liability

Suggested Reading See information below.

Learning Activities (Non-Graded) See information below.

Key Terms 1. Breach of warranty 2. Controls 3. Displays 4. Emergency controls 5. Information

processing 6. Long-term memory 7. Mental workload 8. Negligence 9. Product liability

10. Short-term memory 11. Strict liability 12. Warning

BOS 3701, Industrial Ergonomics 2

measures to evaluate mental workload include factors such as heart rate, eye movement, pupil diameter, muscle tension, electroencephalogram (EEG), electrooculogram (EOG), and electrocardiogram (ECG). Although some of the physiological measures may not be exclusively affected by mental workload, these measures can supplement other assessment methods. The next section deals with controls and displays. Controls activated by hand or foot transmit inputs to the equipment, and the results of the inputs are revealed to the operator by displays or the subsequent actions of the equipment. The type, size, and motion of control should be compatible with stereotypical or population expectations. Also, fine control and small force operations should be done by hand while large force operations should be performed by the feet. Guidelines for control design, types of controls, coding of controls, and emergency controls are well explained in this section. Displays can be visual, auditory, or tactile. A visual display is suitable in a situation where the environment is noisy and the operator is stationary relative to the display. An auditory signal is appropriate when the environment lacks sufficient illumination and the operator must move around. The messages in these displays must be short and simple to require immediate attention. The Consumer Product Safety Commission (CPSC) was established by the Consumer Product Safety Act in 1972. The mission of the CPSC is to protect the public from unreasonable risks of injury from consumer products. Ensuring safety in product design can be accomplished by engineering design, administrative controls, and hazard communication through warning labels. Warning is the least desirable among these three approaches as it is completely dependent on the response of the consumer. The Legal Information Institute at Cornell University (2013) defines a product’s liability as the liability of any or all parties along the chain of manufacture of any product for damage caused by that product. The parties include the manufacturer of component parts, an assembling manufacturer, the wholesaler, and the retail store owner. The three categories of theories of product liability are negligence, strict liability, and breach of warranty. Strict liability is basically identical to negligence except that in strict liability, the plaintiff need not have knowledge about the product. Although products should be safely designed, safety is not always achieved through design alone for some products. In these cases, warning signs are used to alter behavior of the customer. The warning must be sensed through audition, vision, or olfaction. Labels and signs for warnings must be carefully designed according to government regulations.

References Cornell University Legal Information Institute. (2013). Products liability.

Retrieved from http://www.law.cornell.edu/wex/Products_liability

Suggested Reading Cornell University Legal Information Institute. (2013). Products liability.

Retrieved from http://www.law.cornell.edu/wex/Products_liability

BOS 3701, Industrial Ergonomics 3

Learning Activities (Non-Graded) Apply What You Have Learned Complete exercises 9.3, 9.4, and 9.5 on page 302 of your textbook.

1. (9.3) Describe the different types of attention. 2. (9.4) Explain Miller’s chunking theory. 3. (9.5) Explain the NASA TLX approach to subjective workload

assessment. Complete exercises 10.2, 10.3, and 10.5 on page 319 of your textbook.

1. (10.2) What have been some of the historic benefits in manufacturing as a result of product liability cases?

2. (10.3) Identify the branch of the government in our country (or the United States) responsible for consumer product safety and go to the website and obtain an overview of the process used to establish consumer product-safety guidelines.

3. (10.5) Design a warning label for a physically intensive computer- based game (e.g., Wii game) that is used for recreational use.

Non-graded Learning Activities are provided to aid students in their course of study. You do not have to submit them. If you have questions, contact your instructor for further guidance and information.