Human factors is a branch in the scientific field that tries to understand the interaction among humans and other elements of machines, principals, professions data and methods employed in designing in order to optimize human well being, and overall machine performances. The human factors should be put into consideration when in the design phase to enable production of systems that are compatible with the needs, abilities and limitation of their users. Therefore ergonomics can be considered as all the processes that are associated with the application of characteristics of peoples’ abilities and limitations in the designing of equipments they use. This put into considerations environments in which they function and the jobs they function.
The aim of ergonomics is to boost mankind through scientific study and application of scientific principals that relates to the interface of humans and their natural, residential, recreations and vocational environments and the procedures, practices, and design that have being scientifically approved to enhance humans’ performances and safety at the interfaces. This research encompasses the inputs and output elements of machines that the users employ to interact with the machines. To augment their efforts in this field, ergonomics has being involved with numerous psychological, social, physical, and biological researches.
This has greatly boosted their effort in establishing an optimal and safe human performance interface. Therefore human factor is also considered as the scientific discipline that studies how people interact with devices, products, and systems. It is an applied field where behavioral science, engineering, and other disciplines come together to develop the principles that help assure that devices and systems are usable by the people who are meant to use them. The field approaches design with the “user” as its focal point.
Human factors practitioners bring expert knowledge concerning the characteristics of human beings that are important for the design of devices and systems of many kinds. The discipline contributes to endeavors as complex as space exploration and to products as simple as a toothbrush. For example in the field of transportation engineering, there have been numerous important contributions from human factors, but these are not always self-evident. Sight distance requirements, work zone layouts, sign placement and spacing criteria, dimensions for road markings, color specifications, sign letter fonts and icons, signal timing these and many more standards and practices have been shaped by human factors evaluation.
As applied to highway safety, a human factor is concerned with the design of the roadway and operating environment and the vehicle. The three primary components of the highway transportation system the roadway, the vehicle, and the road user all must be compatible with one another. Engineers can design roadways, traffic control devices, and vehicles, but they cannot design the road user. They can design for the road user. Human factors provide an objective basis for doing this. It is based on measured behavior and capabilities rather than assumptions or trial-and-error.
Human factor integration during design phase is vital. This is because it allows the finished products address effectively the limitations of various users. This is because it has been noted that missing access to environments, services and adequate training has been a major cause of social exclusion of disabled people. The access to the opportunities offered by society is obviously limited if these cannot be reached by people with impairments or restricted mobility e.g. people in a wheelchair or blind people. A subtle form of exclusion can result from the sensory modalities in which they are presented. The presentation of information in only one modality excludes people with impairments in that particular sensory modality from access to it e.g. a deaf person has no use for a traditional radio since it provides information only via the auditory sensory mode.
This applies to all areas of information presentation including entertainment, education, and business transactions as well as conversational services. Not being able to use a device or service because its input and output channels support one modality only is a serious restriction of one’s everyday life. For example, it can mean that on-line banking becomes impossible and transactions have to be made personally which may present other additional barriers. Information provided in trains or buses by voice or visual indication seriously restricts those who cannot see or hear thus biased. Similar restrictions exist for large sections of educational programmes. These cannot be used by disabled people thus limiting their options for professional promotion.
Many jobs are designed around a technology that is not designed to provide multimodal interfaces. A large portion of working population is working with technology that requires seeing and hearing. The impact of mono-modality on a person’s social life is also dramatic. A hearing impaired person watching a movie is excluded from the sound, a visually impaired person from the picture. In such a case often friends or members of the family compensate this by verbally explaining to a blind person or by signing to a deaf person. Therefore human factor consideration in designing phase is very necessary as it allows designing of systems that enables multimodality as compensation for the impaired. Multimodality, understood as the optional presentation of the same information content in more than one sensory mode, can compensate to a certain degree for sensory impairments. Some of systems that have been designed to allow multimodality include Television and Cinemas. But these facilities are also still wanting because Television and cinema shows are by their nature multimodal events, requiring both seeing and hearing to be able to fully understand and appreciate the content.
Therefore integration of human factor in Television in their designing phase is importance as it can lead to multimodality to compensate the lack of one sensory mode in a person by presenting the information in another mode. This can be achieved by subtitling i.e. a textual representation of the dialogue and the sounds. The representation of dialogues only, as can be found in some broadcast and DVD programmes, is only of limited use to deaf people if reference to sound events like shots or thunder is missing. Similarly, not being able to see the action on the screen can be compensated by audio commentary which may possibly be somewhat disturbing to a seeing audience.
Programmes broadcast with audio commentary for blind people usually transmitted on the second stereo channel are still rare, even rarer are audio commentary tracks for blind people on DVD. Audio tracks are, however, often used for the director’s comments. With efficient use of human factors in the designing phase, user interfaces of almost all devices and services can be designed or extended to encompass the principle of multimodality. An optional voice-prompt can lead a blind person through the process of withdrawing money from an ATM, a visual menus can support the deaf person using a telephone e.g. for text messaging. Therefore human factor should be an integral part of the design process to promote the performances of produced products.