Key definitions

The following definitions are given to clarify the meaning of the main terms used in this study context.

Attribute:

perceived property of a product (also used by market researchers)

Bottom-up:

product design process starting from the needs of users (customer needs)

Characteristic:

property of a product, engineering feature or parameter

Consistency:

an experimental finding is considered to be the reliable and consistent if it can be replicated under similar conditions at a later time (Cushman & Rosenberg 1991)

Criterion:

see Objective

Decision analysis:

a technique assisting in the choice of an action and its course in view of the objectives, the other alternatives and the risks involved (Logothetis 1992); background for decision-making

Descriptive study:

seeks to characterise a population in terms of certain attributes and to describe the performance and behaviours of the people using the system and the product (Sanders & McCormick 1993)

Design:

a process to create a system or a product with functions that meet some needs, the process of devising and laying down the plans that are needed for the manufacturing of a product (Roozenburg & Eekels 1995); the result of a design process

Ecological validity:

how closely the test environment resembles the actual environment in which the product is used

Ergonomics:

the scientific foundation, both in terms of data and methodology, for a user-centred approach to design (Pheasant 1988); knowledge and methods that aim to develop product, equipment, furniture and environment to fit the user’s capabilities and to promote user safety

Evaluation:

assessing the effect of “something”, judging or fixing the value or worth of something

Evaluative research:

research aiming at assessing the effect of “something”

Experiment:

in an experiment, the investigator sets the users a series of tasks and quantifies their performance

Experimental ergonomic evaluation (EEE):

with the aid of user trials and statistics, the user or/and the designer together produce elements for evaluating the measured or/and perceived properties of a new product/system to make it “user-friendly” and useful; possible further gathering of relevant elements for a total multi-criteria decision

Experimental research:

research to find out whether a variable has an effect on behaviour and the direction of that effect

Expert analysis:

a specialist of a specific issue makes observations and conclusions

Gerontechnology:

the study of ageing and technology for the benefit of improved living and working environments for the elderly and their caregivers

Human-technology system:

an interacting combination of an individual and an artefact, i.e. a user and a product or a human and a machine

Implementation phase:

introduction a new system or product into a real context and tasks; adaptation of the personnel of the organisation to the changes in their work caused by the new system or product

Iterative design:

the procedure in which the fulfilment of requirements concerning a product solution is evaluated and the design is repeated until the solution meets the requirements

Measure:

to determine by measurement the values of a variable

Measure quantitatively:

to determine objectively or subjectively a value for a variable on a numeric scale

Multi-criteria decision:

a decision for which the product is evaluated in terms of different criteria simultaneously

Objective:

related to the requirements of a product, presented as requirement specifications

Objective assessment:

measurement of the interaction between the user and the product objectively, observation of user-product interaction uninfluenced by personal prejudice

Observation:

methodology by which researchers observe (visually) the phenomena of user-product interaction systematically, directly or based on recordings

Operational fidelity:

refers to the relationship between the operational environment and the testing environment (Sanders & McCormick 1993); cf. ecological validity

Participation:

user involvement in the design and evaluation of the product with a possibility to influence the decision

Perception, perceived:

the process of becoming aware of something through the senses and achieving understanding of it; the process of interpretation based on sensation

Performance:

the degree to which a product fulfils the numeric objectives set for it

Preference:

preferring, i.e. choosing as more desirable; something that is superior to another item or items

Product:

something sold by an enterprise to its customer (Ulrich & Eppinger 2000); an artefact used by people because of its properties and functions

Product development:

a set of activities beginning with the perception of a market opportunity and ending in the production, sale, and delivery of a product (Ulrich & Eppinger 2000).

Property:

actual analysed quality of a product, described as values of actual variables

Prototype:

a demonstrator to be created to represent the product built for testing and experimentation

Qualitative methods:

methodology which tries to explain the phenomena to be studied without quantitative methods by using, for example, stories or citations from discussion

Quantitative methods:

methodology which aims to explain the phenomena to be studied numerically, using metrics

Reliability:

the degree of giving the same result on successive trials; something that is reliable, i.e., can be trusted because it works well

Requirement:

a demand applied to the product by the user or someone else

Segmentation:

to divide the population into homogeneous groups according to product, user or purchase situation characteristics

Simulation:

(physical) representation of equipment, events and task performance (Meister 1995)

Specification:

description of the characteristics and functions of a product, description of the product requirements to help the design process

Subject:

an individual interacting in an experiment, a user in a user trial, an individual involved in some way in a study

Subjective:

dependent on personal taste or views, etc. (Oxford Minidictionary)

Subjective assessment:

the involved user and his/her perception and/of opinion about the target to be evaluated

System:

a combination of multiple elements or components

Task:

the activities required (used or believed to be necessary) to achieve a defined and desired goal

Top-down:

a product design process starting from (the management of) the manufacturer

Usability:

the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use (ISO 9241-11 1998)

Usability engineering:

measurement of the usability of a product to find out the needed characteristics of the developed product, measurement and development of usability characteristics vs. requirements

Usability study:

systematic heuristic or experimental evaluation of the interaction between people and the products, equipment and environments they use; cf. user trial

User, end-user, human, citizen, consumer, individual, customer:

individual human being interacting with a product or system

User-centred design:

designing for users with users; optimising the interactive system of the user, the product and the task in the context of an organisation and the environment

User-interface:

a combination of parts, ways and procedures (technology) through which a user interacts with a product both cognitively and physically; the assessable aspects of the interface between a product and a human

User participation:

see participation

User trial:

experimental investigation in which a group of users test versions of a product under controlled conditions (Pheasant 1996), usability trial within research; cf. usability study

Validity:

the extent to which different variables actually measure what they were intended to measure (Sanders & McCormick 1993); the degree of verification/confirming

Variable:

cf. property