Target and Spacing Sizes for Smartphone User Interfaces for Older Adults: Design Patterns Based on an Evaluation with Users

The use of smartphones is becoming widespread among all sectors of the population. However, developers and designers do not have access to guidance in designing for specific audiences such as older adults. This study investigated optimal target sizes, and spacing sizes between targets, for smartphones user interfaces intended for older adults. Two independent variables were studied – target sizes and spacing between targets – for two common smartphone gestures – tap and swipe. Dependent variables were accuracy rates, task completion times, and participants’ subjective preferences. 40 older adults recruited from several daycare centers participated in both tasks and a post-session questionnaire. The recommendations drawn from the authors’ research support two interaction design patterns relative to touch target sizes for older adults, and are presented in this paper

Target and Spacing Sizes for Smartphone User Interfaces for Older Adults: Design Patterns Based on an Evaluation with Users

The use of smartphones is becoming widespread among all sectors of the population. However, developers and designers do not have access to guidance in designing for specific audiences such as older adults. This study investigated optimal target sizes, and spacing sizes between targets, for smartphones user interfaces intended for older adults. Two independent variables were studied – target sizes and spacing between targets – for two common smartphone gestures – tap and swipe. Dependent variables were accuracy rates, task completion times, and participants’ subjective preferences. 40 older adults recruited from several daycare centers participated in both tasks and a post-session questionnaire. The recommendations drawn from the authors’ research support two interaction design patterns relative to touch target sizes for older adults, and are presented in this paper

Understanding grip shifts:how form factors impact hand movements on mobile phones

In this paper we present an investigation into how hand usage is affected by different mobile phone form factors. Our initial (qualitative) study explored how users interact with various mobile phone types (touchscreen, physical keyboard and stylus). The analysis of the videos revealed that each type of mobile phone affords specific handgrips and that the user shifts these grips and consequently the tilt and rotation of the phone depending on the context of interaction. In order to further investigate the tilt and rotation effects we conducted a controlled quantitative study in which we varied the size of the phone and the type of grips (Symmetric bimanual, Asymmetric bimanual with finger, Asymmetric bimanual with thumb and Single handed) to better understand how they affect the tilt and rotation during a dual pointing task. The results showed that the size of the phone does have a consequence and that the distance needed to reach action items affects the phones’ tilt and rotation. Additionally, we found that the amount of tilt, rotation and reach required corresponded with the participant’s grip preference. We finish the paper by discussing the design lessons for mobile UI and proposing design guidelines and applications for these insights

Mixed method approach in designing flight decks with touch screens: a framework

Touch screen technology’s first public appearance was in the early 2000s. Touch screens became a part of the daily life with the invention of smartphones and tablets. Now, this technology has the potential to be the next big change in flight deck design. To date, mobile devices are deployed by several air carriers to perform a host of non-safety critical pre-flight and in-flight tasks. Due to high safety requirements requested by authorities, new technologies cannot be adopted as fast as in other settings. Flight deck evolution, which is briefly presented in this paper, is reflecting this natural time delay. Avionics manufacturers are exploring and working on future concepts with touch screen displays. This paper investigates the potential benefits and challenges of touch screen technology on flight decks by means of a variety of qualitative and quantitative research methods (mixed method approach). On the basis of this, a framework was constructed showing the relation between various aspects that could impact the usability of touch screens on the flight deck. This paper concludes with a preliminary questionnaire that can help avionic designers to evaluate whether a touch screen is an appropriate user interface for their system

Ley de Fitts: Sobre el Cálculo del Rendimiento y Tareas No ISO

We used a target-selection task to evaluate head-tracking as an input method for mobile devices. First, the method of calculating Fitts’ throughput is described by means of a raw data detailed example. Then, the method of calculating throughput is discussed for non-ISO tasks, since the procedure targets were randomly positioned from trial to trial. Due to a non-constant amplitude within each sequence of trials, throughput was calculated using two methods of data aggregation: the first one, by sequence of trials using the mean amplitude, and the second one, by common A-W conditions. For each data set, we used four methods for calculating throughput. The grand mean for throughput (calculated through the division of means and the adjustment for accuracy) was of 0.74 bps, which is 45 % lower than the value obtained using an ISO task. We recommend to calculate throughput using the division of means plus the adjustment for accuracy, and to avoid using the reciprocal slope of the regression model. We present various design recommendations for non-ISO tasks, such as: i) to keep amplitude and constant target within each sequence of trials, and ii) to use strategies to avoid or remove reaction time.En este trabajo se presenta el uso de una tarea de selección de objetivos en la evaluación de un head-tracker para dispositivos móviles. Primero, se describe el método de cálculo del rendimiento mediante un ejemplo detallado. A continuación, se discute el método de cálculo para tareas que no cumplen el estándar ISO. Debido a la amplitud no constante de la tarea dentro de cada secuencia, se calcula el rendimiento utilizando dos métodos de agregación de datos: por secuencia, calculando la amplitud media, y por condiciones comunes A-W. Se recomienda calcular el rendimiento utilizando la división de medias y el ajuste de precisión. La media general de rendimiento ha sido de 0,74 bps (un 45 % menor que con una tarea ISO). Se presentan dos recomendaciones de diseño para tareas que no cumplen el estándar ISO: mantener constantes A-W dentro de cada secuencia y utilizar estrategias para evitar el tiempo de reacción

Fitts’ Law: On Calculating Throughput and Non-ISO Tasks

We used a target-selection task to evaluate head-tracking as an input method for mobile devices. First, the method of calculating Fitts’ throughput is described by means of a raw data detailed example. Then, the method of calculating throughput is discussed for non-ISO tasks, since the procedure targets were randomly positioned from trial to trial. Due to a non-constant amplitude within each sequence of trials, throughput was calculated using two methods of data aggregation: the first one, by sequence of trials using the mean amplitude, and the second one, by common A-W conditions. For each data set, we used four methods for calculating throughput. The grand mean for throughput (calculated through the division of means and the adjustment for accuracy) was of 0.74 bps, which is 45 % lower than the value obtained using an ISO task. We recommend to calculate throughput using the division of means plus the adjustment for accuracy, and to avoid using the reciprocal slope of the regression model. We present various design recommendations for non-ISO tasks, such as: i) to keep amplitude and constant target within each sequence of trials, and ii) to use strategies to avoid or remove reaction time

Understanding Grip Shifts: How Form Factors Impact Hand Movements on Mobile Phones

In this paper we present an investigation into how hand usage is affected by different mobile phone form factors. Our initial (qualitative) study explored how users interact with various mobile phone types (touchscreen, physical keyboard and stylus). The analysis of the videos revealed that each type of mobile phone affords specific handgrips and that the user shifts these grips and consequently the tilt and rotation of the phone depending on the context of interaction. In order to further investigate the tilt and rotation effects we conducted a controlled quantitative study in which we varied the size of the phone and the type of grips (Symmetric bimanual, Asymmetric bimanual with finger, Asymmetric bimanual with thumb and Single handed) to better understand how they affect the tilt and rotation during a dual pointing task. The results showed that the size of the phone does have a consequence and that the distance needed to reach action items affects the phones’ tilt and rotation. Additionally, we found that the amount of tilt, rotation and reach required corresponded with the participant’s grip preference. We finish the paper by discussing the design lessons for mobile UI and proposing design guidelines and applications for these insights