Target User Population Research Articles

Considering Secular and Demographic Trends in Designing Long Lifetime Products for Target User Populations

The objective of this study is to investigate the effects of design decisions on the accommodation afforded by long lifetime products over extended periods of time, and to then make recommendations to improve accommodation. Phenomena such as rising obesity rates, aging, and changes in user demography can affect the spatial and the physical requirements of the user population. As a result, products with long lifetimes must be robust to these secular and demographic trends. For example, heavy (e.g., Society of Automotive Engineers (SAE) Class B) trucks are often used for decades. Changes in the size and the shape of truck drivers and in the percentage of female truck drivers have placed unanticipated demands on older trucks and forced designers to predict future needs. This work concludes that for changes related to secular trends (e.g., increasing obesity and stature), products that work well for current populations are the most likely to be robust to the needs of future ones. However, changes in user demographics (i.e., different proportions of race, ethnicity, and gender) are more likely to be problematic.

Considering race and gender distributions of the target user population in the multivariate design of vehicle seating

The spatial dimensions of vehicle seats affect their ability to accommodate the physical requirements of the target user population. This paper presents a methodology for selecting the relevant design parameters, including the width, depth, and height of the pan as well as the height of the back. The paper also explores the effect of gender and racial composition of the user population on these parameters. The results obtained through univariate analysis are compared with those of multivariate analysis, demonstrating that applying univariate analysis to a multivariate problem leads to misleading results and poor estimates of accommodation. In contrast, multivariate analysis provides the opportunity for tradeoff studies as many parameter combinations can achieve the desired accommodation level. The methodology is demonstrated through several design scenarios for target user populations of different racial and gender distributions.

가상 환경 상의 헬리콥터 조종실 설계를 위한 정량적인 인간공학적 평가 방법 개발

For the development of a better product which fits to the target user population, physical workloads such as reach and visibility are evaluated using digital human simulation in the early stage of product development; however, ergonomic workload assessment mainly relies on visual observation of reach envelopes and view cones generated in a 3D graphic environment. The present study developed a quantitative assessment method of physical workload in a digital environment and applied to the evaluation of a Korean utility helicopter (KUH) cockpit design. The proposed assessment method quantified physical workloads for the target user population by applying a 3-step process and identified design features requiring improvement based on the quantified workload evaluation. The scores of physical workloads were quantified in terms of posture, reach, visibility, and clearance, and 5-point scales were defined for the evaluation measures by referring to existing studies. The postures of digital humanoids for a given task were estimated to have the minimal score of postural workload by finding all feasible postures that satisfy task constraints such as a contact between the tip of the index finger and a target point. The proposed assessment method was applied to evaluate the KUH cockpit design in the preliminary design stage and identified design features requiring improvement. The proposed assessment method can be utilized to ergonomic evaluation of product designs using digital human simulation.

Consideration of Demographics and Variance in Regression Approaches to Estimating Body Dimensions for Spatial Analysis of Design

A common objective in designing for human variability is to consider the variability in body size and shape of the target user population. Since anthropometric data specific to the user population of interest are seldom available, the variability is approximated. This is done in a number of ways, including the use of data from populations that are well-documented (e.g., the military), proportionality constants, and digital human models. These approaches have specific limitations, including a failure to consider the effects of lifestyle and demography, resulting in products, tasks, and environments that are inappropriately sized for the actual user population, causing problems with safety, fit, and performance. This paper explores a regression-based approach in a context where the demographic distributions of descriptors (e.g., race/ethnicity, age, and fitness) are dissimilar for the database and target population. Also examined is a stratified regression model involving the development of independent anthropometry-estimation models for each racial group. When using regression with residual variance, stratification on the predictor demographics to obtain estimates of gender, stature, and BMI distributions is shown to be sufficiently robust for usual database-target population combinations. Consideration of demographic variables in development of the regression model provides marginal improvement, but could be appropriate in specific situations.

Designing for Usability of an Adaptive Time Management Assistant

This case study article describes the iterative design process of an AI‐based mixed‐initiative calendaring tool with embedded artificial intelligence. We establish the specific types of assistance in which the target user population expressed interest, and we highlight our findings regarding the scheduling practices and the reminding preferences of these users. These findings motivated the redesign and enhancement of our intelligent system. Lessons learned from the study—namely, that AI systems must be usable to gain widespread adoption and retention and that simple problems that perhaps do not necessitate complex AI‐based solutions should not go unattended merely because of their inherent simplicity—conclude the article, along with a discussion of the importance of the iterative design process for any user adaptive system.

Including Preference in Anthropometry-Driven Models for Design

In the design of artifacts that interact with people, the spatial dimensions of the target user population are often used to determine the requirements of the engineered artifact. The expected variability in body dimensions (called “anthropometry”) is used to indicate how much adjustability or how many sizes are required to accommodate the intended user population. However, the quantification of anthropometric variability alone is not sufficient to make these kinds of assessments in many situations. For example, two vehicle drivers with similar body dimensions might have different preferred locations for the seat. In these situations, preference can be broken down into two components: that explained by body size and the variability that remains. By quantifying the magnitude of both sources, preference can be included in modeling strategies and design decision-making. This improves the accuracy of models and predictions, and can facilitate the application of design automation tools such as optimization and robust design methodologies, resulting in products that are safer, cost effective, and more accessible to broader populations (including people with disabilities). In contrast, failure to include variability in preference that is not attributable to anthropometry can produce misleading results that under- or over-approximate accommodation and prescribe inappropriate amounts of adjustability. A simulation-based approach for modeling both sources of variability and conducting designing for human variability (DfHV) assessments is presented. A stochastic component based on the residual variance in regression analysis relating body dimensions to experimental data is included in the predictive model. This ensures that a distribution of preferred configurations is produced for any given set of body dimensions. The effect of including both components of preference is quantified by comparing this approach to two traditional DfHV approaches in the context of a simple, univariate case study to determine the appropriate allocation of adjustability to achieve a desired accommodation level.

Creating virtual user populations by analysis of anthropometric data

Anthropometric measures that accurately represent the target user population are essential to effective designing for human variability, yet the available anthropometric data are drawn from populations that are substantially dissimilar from the target populations for most products and environments. Many designs for civilians are assessed using military anthropometric data, for example, because the only available data with sufficient detail were gathered from soldiers. Recent studies have collected detailed information from civilians, but these populations are also not representative of typical user populations. This paper presents a new statistical method for applying the available anthropometric data to estimate distributions of anthropometric data for a target population. For many design problems, the target population can be characterized by overall demographic information, such as the gender ratio, age distribution, nationality, and ethnicity. Principal component analysis and linear regression are used to create statistical models that can draw on information from two or more databases to estimate values for a large range of anthropometric variables. The approach matches the race/ethnicity distribution of the target user population and incorporates a stochastic component so that all relevant variance is retained. Finally, it generates populations of virtual users rather than summary statistics for individual variables. Summary statistics from the virtual populations are shown to be reasonable approximations for the actual measures. This work has application to a wide range of design problems, including the design of workspaces, vehicles, and medical devices. Relevance to industry: Accurate estimates of target user anthropometry are essential to spatial analyses in artifact and task design. This paper presents a methodology for using available data to synthesize new populations that better represent target users. Application of these methods in the design and assessment of products and environments will produce more accommodating designs that promote better performance and customer acceptance.

User Assessment as Input for Useful Geospatial Representations within Mobile Location-Based Services

Mobile Location-Based Services (mLBS) are an increasingly consumer-based concept borne from, and continually driven by, technology-centred development; as opposed to the needs of end users. Where users have been made a focus, the research generally concerns issues of overall system appearance, functionality, information content and interaction methods, with little emphasis on the component geospatial representations. This paper describes the initial stages of a research project aimed at filling this void through the application of a qualitative User-Centred Design (UCD) methodology for optimising geospatial representations within mLBS applications, in order to support a selected user group: Australian ‘leisure-based travellers’. Presented in this paper is an account of two UCD activities adopted for the research. The first, user profiling, served to define the target user population in terms of their technological, geospatial and travel experiences, using an online questionnaire. The second, user task analysis, involved in-depth interviews with a subset of users in order to obtain a deeper understanding of the geospatial goals, tasks, needs and preferences within the population, as well as the range of user differences and variability in tasks present. An overall user assessment, through combined analysis of the two result sets, highlighted considerations for the ongoing research, including a set of specific implications for the design of alternative models for geospatial services, representations and interactions. The themes described in this paper represent an initial and necessary component of UCD, which has been largely overlooked in research relating to mLBS. Whilst the focus here is on a specific user group and context of use, it is envisaged that many of the concepts tested and ratified by the resulting models will be relevant to mLBS applications in general.

A Process-Oriented Interactive Design Environment for Automatic User-Interface Adaptation

In the design of user interfaces that adapt automatically to end-users and usage contexts, designers should be prepared to cope with large design spaces; these spaces will be necessary to accommodate design constraints posed by the diversity in the target user population and the various contexts of use. Adaptation-oriented design is considered a powerful design recipe addressing the compelling requirements of customization, accessibility, and high quality of interaction. Under this perspective, it must be carefully planned, designed, accommodated, and conducted within the life cycle of interactive systems, from the early exploratory phases of design and prototyping to evaluation, implementation, and deployment. Despite recent progress, the practice of designing automatic user-interface adaptations remains difficult, due to intrinsic complexity of the task and the current limited expertise of designers and practitioners. Toward overcoming such a difficulty, this article presents MENTOR, a tool providing (a) practical integrated support for all phases of adaptation design, through appropriate editing facilities; (b) practical support for a "smooth transition" from design to development through the availability of automated verification mechanisms for the designed adaptation logic, as well as the automated generation of "ready-to-implement" interface specifications; and (c) support for the progressive accumulation of design cases and of the related design experience and knowledge, in particular regarding adaptation.

Introduction

New computing and communication platforms create the possibility for new business models and new applications to support and enhance our lives. But new platforms also challenge us to reinvent design methods and principles. As new technology becomes mainstream, designs and business models that work for the target user population and business are a critical success factor. Mobile devices are opening up new business opportunities, new conveniences for users, and new design challenges.

Priorities for Technological Research for Visually Impaired People

It can take a number of years from the specification of a research project to the outcome being of practical benefit to blind and partially sighted people. Since there are finite resources, both of funds and skilled staff, for research, it is important to carefully analyse the likely future unmet needs of the target user population before determining priorities for research. This is not trivial since both technology and user needs will change with time. At present, much of the technological research is targeted at people using non-visual means of communication and who do not have additional impairments. The demographic trends, however, are for an increasing proportion of visually impaired people to have a significant additional impairment. Much of the current technological research relates to developing sophisticated devices for blind people of above average intelligence. Yet, there is an unmet need for many low-cost devices: for instance, devices for opening new types of packaging of domestic products. T...

Collaborative document annotation using electronic mail

The primary purpose of this paper is to describe an approach to software development, the small scale approach, that is particularly appropriate for groupware that has a target user population that is truly global. Many of the reasons why the small scale approach is appropriate are described. To support the paper's primary purpose, the domain of document annotation in collaborative writing is used to illustrate the requirements of such global groupware. A simulation shows how the proposed software might be used by individuals and how annotations might be automatically combined. The requirements analysis from this leads to a high level program design which is implemented, for illustration, as a PERL program.

Playback: A method for evaluating the usability of software and its documentation

Human factors evaluations of software products and accompanying user publications must be conducted so that developers can be certain that the target user population can learn to use the product with a minimum of difficulty and be able to perform the intended tasks efficiently. A methodology is described for obtaining objective measures of product usability by collecting perfor-mance data on the user interface without affecting the user or the system being evaluated. The log of stored activity is later played back through the host system for analysis.