Predicting and Reducing the Impact of Errors in Character-Based Text Entry

This dissertation focuses on the effect of errors in character-based text entry techniques. The effect of errors is targeted from theoretical, behavioral, and practical standpoints. This document starts with a review of the existing literature. It then presents results of a user study that investigated the effect of different error correction conditions on popular text entry performance metrics. Results showed that the way errors are handled has a significant effect on all frequently used error metrics. The outcomes also provided an understanding of how users notice and correct errors. Building on this, the dissertation then presents a new high-level and method-agnostic model for predicting the cost of error correction with a given text entry technique. Unlike the existing models, it accounts for both human and system factors and is general enough to be used with most character-based techniques. A user study verified the model through measuring the effects of a faulty keyboard on text entry performance. Subsequently, the work then explores the potential user adaptation to a gesture recognizer’s misrecognitions in two user studies. Results revealed that users gradually adapt to misrecognition errors by replacing the erroneous gestures with alternative ones, if available. Also, users adapt to a frequently misrecognized gesture faster if it occurs more frequently than the other error-prone gestures. Finally, this work presents a new hybrid approach to simulate pressure detection on standard touchscreens. The new approach combines the existing touch-point- and time-based methods. Results of two user studies showed that it can simulate pressure detection more reliably for at least two pressure levels: regular (~1 N) and extra (~3 N). Then, a new pressure-based text entry technique is presented that does not require tapping outside the virtual keyboard to reject an incorrect or unwanted prediction. Instead, the technique requires users to apply extra pressure for the tap on the next target key. The performance of the new technique was compared with the conventional technique in a user study. Results showed that for inputting short English phrases with 10% non-dictionary words, the new technique increases entry speed by 9% and decreases error rates by 25%. Also, most users (83%) favor the new technique over the conventional one. Together, the research presented in this dissertation gives more insight into on how errors affect text entry and also presents improved text entry methods

A novel interface for first person shooter games on personal digital assistant devices

Includes abstract.Includes bibliographical references (leaves 71-73).The main aim of this study is to enhance the playability of games on current standard PDA devices. The newly designed interface more effectively leverages current well-established devices, which solves the problem of rapidly and accurately executing a large number of gaming commands. The outcomes of this research are beneficial for interface design of mobile applications

Optimizing Human Performance in Mobile Text Entry

Although text entry on mobile phones is abundant, research strives to achieve desktop typing performance "on the go". But how can researchers evaluate new and existing mobile text entry techniques? How can they ensure that evaluations are conducted in a consistent manner that facilitates comparison? What forms of input are possible on a mobile device? Do the audio and haptic feedback options with most touchscreen keyboards affect performance? What influences users' preference for one feedback or another? Can rearranging the characters and keys of a keyboard improve performance? This dissertation answers these questions and more. The developed TEMA software allows researchers to evaluate mobile text entry methods in an easy, detailed, and consistent manner. Many in academia and industry have adopted it. TEMA was used to evaluate a typical QWERTY keyboard with multiple options for audio and haptic feedback. Though feedback did not have a significant effect on performance, a survey revealed that users' choice of feedback is influenced by social and technical factors. Another study using TEMA showed that novice users entered text faster using a tapping technique than with a gesture or handwriting technique. This motivated rearranging the keys and characters to create a new keyboard, MIME, that would provide better performance for expert users. Data on character frequency and key selection times were gathered and used to design MIME. A longitudinal user study using TEMA revealed an entry speed of 17 wpm and a total error rate of 1.7% for MIME, compared to 23 wpm and 5.2% for QWERTY. Although MIME's entry speed did not surpass QWERTY's during the study, it is projected to do so after twelve hours of practice. MIME's error rate was consistently low and significantly lower than QWERTY's. In addition, participants found MIME more comfortable to use, with some reporting hand soreness after using QWERTY for extended periods

Improving usability in pan gateways by means of a novel Bluetooth pairing method

This thesis investigates the usability issues surrounding an implementation of the Personal Area Network (PAN) Gateway, a new concept in mobile communications. The PAN Gateway device consists of a GSM/GPRS modem and a Bluetooth modem. The Bluetooth modem is used to link mobile devices to form a PAN and the GSM/GPRS modem is used to link the PAN to external networks. The possible Man Machine Interfaces for the PAN Gateway are discussed together with the usability of existing Bluetooth devices. A weakness was discovered in the usability and security of Bluetooth Pairing in existing mobile devices and this led to the development of the "Touch and Find" system and the Pairing Link Protocol. The "Touch and Find" system interacts with the Bluetooth stack and allows simple, intuitive pairing of Bluetooth devices via a serial link. A full duplex serial link was implemented using simple electrical contacts to provide the link. Inductive coupling and infrared solutions were also developed. The Pairing Link Protocol specifies the signal flow for the "Touch and Find" process. The "Touch and Find" system that was implemented using simple electrical contacts shows how simple Bluetooth pairing can be. Pairing is simply carried out by briefly touching together the devices to be paired. The "Touch and Find" system was implemented in C on Borland C++ and used in conjunction with TTPCom's Bluetooth development system, which consists of a "Mad Cow" evaluation board and Genie - a Bluetooth development tool. The research carried out demonstrates the feasibility of the "Touch and Find" system over a variety of physical mediums. The system greatly improves the usability of Bluetooth Pairing, thus improving the "Out of Box" experience. It is likely that the Inductive solution can be extended to enable battery charging across the "Touch and Find" Inductive interface, further enhancing the "value added" capabilities of this system

Designing multimodal interaction for the visually impaired

Although multimodal computer input is believed to have advantages over unimodal input, little has been done to understand how to design a multimodal input mechanism to facilitate visually impaired users\u27 information access. This research investigates sighted and visually impaired users\u27 multimodal interaction choices when given an interaction grammar that supports speech and touch input modalities. It investigates whether task type, working memory load, or prevalence of errors in a given modality impact a user\u27s choice. Theories in human memory and attention are used to explain the users\u27 speech and touch input coordination. Among the abundant findings from this research, the following are the most important in guiding system design: (1) Multimodal input is likely to be used when it is available. (2) Users select input modalities based on the type of task undertaken. Users prefer touch input for navigation operations, but speech input for non-navigation operations. (3) When errors occur, users prefer to stay in the failing modality, instead of switching to another modality for error correction. (4) Despite the common multimodal usage patterns, there is still a high degree of individual differences in modality choices. Additional findings include: (I) Modality switching becomes more prevalent when lower working memory and attentional resources are required for the performance of other concurrent tasks. (2) Higher error rates increases modality switching but only under duress. (3) Training order affects modality usage. Teaching a modality first versus second increases the use of this modality in users\u27 task performance. In addition to discovering multimodal interaction patterns above, this research contributes to the field of human computer interaction design by: (1) presenting a design of an eyes-free multimodal information browser, (2) presenting a Wizard of Oz method for working with visually impaired users in order to observe their multimodal interaction. The overall contribution of this work is that of one of the early investigations into how speech and touch might be combined into a non-visual multimodal system that can effectively be used for eyes-free tasks

Identification of the initial rule-base of a multi-stroke fuzzy-based character recognition method with meta-heuristic techniques

This paper summarizes the basic concept of the designed a fuzzy-based character recognition algorithm family and the results of the optimization of its rule-base with two various meta-heuristic methods, the Imperialist Competitive Algorithm and the bacterial evolutionary algorithm. The results are presented and compared with two other methods from literature after a short overview of the recognition algorithm

Chinese Text Entry with Mobile Devices

Tietokoneiden ja nykyaikaisten matkapuhelimien käytön kannalta on olennaista, että niihin voidaan syöttää tekstiä tehokkaasti. Kiinan kielen eri murteita puhuu äidinkielenään noin viidesosa maailman väestöstä eli yli miljardi ihmistä. Kiinan kielen merkki- ja tavuperustaisuus tekee siitä tekstinsyötön kannalta ainutlaatuisen haastavan. Monet kiinalaisista merkeistä ovat rakenteeltaan monimutkaisia ja homofonisia (ääntyvät samalla tavoin) joidenkin muiden merkkien kanssa. Syötettäessä tekstiä näppäimistöltä tavallinen tapa on käyttää ns. pinyin-koodeja, joiden avulla kukin kiinan merkki voidaan esittää useasta latinalaisen aakkoston merkistä koostuvana koodina. Homofoniasta johtuen tarkoitettu kiinan kielen merkki joudutaan tämän jälkeen vielä valitsemaan usean vaihtoehdon joukosta, mikä tekee tekstinsyöttöprosessista vaikeampaa kuin romaanisten kielten tapauksessa. Lisäksi on otettava huomioon Kiinan eri osissa puhutut useat murteet. Kaikki nämä tekijät yhdessä tekevät kiinankielisen tekstin syötöstä tietokoneille haastavaa. Tämän väitöskirjan tavoitteena on parantaa kiinankielisen tekstin syöttötapojen käyttäjäkokemusta käytettäessä matkapuhelimia ja muita mobiililaitteita. Väitöskirjassa tutkitaan empiiristen kokeiden ja mallinnuksen avulla uusia tekstinsyöttötapoja ja niiden käyttöä. Tutkimuksen kohteena on neljä erilaista tekstinsyöttötapaa: kiinankielen käsinkirjoituksen tunnistus, pyörivän kiekon avulla tapahtuva tekstinsyöttö, mandariinikiinaan perustuva sanelu, ja numeronäppäinten avulla tapahtuva pinyin-koodien syöttö. Työssä ehdotetaan uusia tekniikoita sekä käsinkirjoituksen tunnistukseen että kiekkoa käyttävään pinyin-koodien syöttöön. Empiirisissä kokeissa osoittautui että käyttäjät pitivät uusista tekniikoista. Mandariinikiinalle on suunniteltu lyhytviestien sanelusovellus, josta on tehty kaksi käyttäjäkoetta. Myös numeronäppäinten avulla tapahtuvaa pinyin-koodien syöttöä on tutkittu kahdessa kokeessa. Ensimmäisessä kokeessa vertailtiin viittä eri menetelmää. Se tuotti suunnitteluohjeita etenkin koskien fraasien (useamman merkin kokonaisuuksien) syöttöä, tekniikkaa joka voi nopeuttaa tekstinsyöttöä. Toisen osatutkimuksen tuloksena on tekstinsyöttöä kuvaava malli, jonka avulla voidaan ennustaa menetelmän nopeutta kun syötettäessä ei tehdä virheitä. Tutkimus johti myös useisiin jatkotutkimuskysymyksiin. On tarpeen kehittää tehokkaampia menetelmiä tilanteeseen, jossa merkki joudutaan valitsemaan useista vaihtoehdoista. Kehityspotentiaalia on myös merkkien perustana olevien viivojen tunnistustavoissa sekä kosketusnäytöllä esitettyjen näppäimistöjen paremmassa hyödyntämisessä.For using computers and modern mobile phones it is essential that there are efficient methods for providing textual input. About one fifth of the world´s population, or over one billion people, speaks some variety of Chinese as their native language. Chinese has unique characteristics as a logosyllabic language. For example, many Chinese characters are complex in structure and normally homophonic with some others. With keyboards and other key-based input devices the normal approach is to use so-called pinyin input, where the Chinese characters are entered using their pinyin mark that consists of several characters in the Roman alphabet. Because of homophony this technique requires choosing the correct Chinese character from a list of posssible choices, making the input process more complicated than in Roman languages. Moreover, the many varieties of the language in different parts of China have to be taken into account as well. All above factors bring new challenges to the design and evaluation of Chinese text entry methods in computing systems. The overall objective of this dissertation is to improve user experience of Chinese text entry on mobile devices. To achieve the goal, the author explores new interaction solutions and patterns of user behavior in the Chinese text entry process with various approaches including empirical studies and performance modeling. The work covers four means of Chinese text entry on mobile devices: Chinese handwriting recognition, Chinese indirect text entry with a rotator, Mandarin dictation, and Chinese pinyin input methods with a 12-key keypad. New design solutions for Chinese handwriting recognition and pinyin methods utilizing a rotator are proposed and proved being well accepted by users with empirical studies. A Mandarin short message dictation application for mobile phones is also presented , with two associated studies on human factors. Two studies were also carried out on Chinese pinyin input methods that are based on the 12-key keypad. The comparative study of five phrasal pinyin input methods led to design guidelines for the advanced feature of phrasal input. The second study of pinyin input methods produced a predictive model addressing users´ error-free speeds. Based on the conclusions from studies in this thesis, several additional research questions were identified for the future. For example, improvements are necessary to promote user performance on target selection process in Chinese text entry on mobile devices. Moreover, design and studies on stroke methods and Chinese specific soft keyboards are also required

User interface design considerations for emerging input technologies in iTV

Streaming media and interactive television viewing experiences are becoming more commonplace with the introduction of services such as Netflix Streaming, the Apple TV, and Google TV aided by the increase adoption of broadband internet. As these services make their way into the living room, and developers struggle to accommodate more complex interaction requirements, new input methods and interfaces need to be developed. Current interfaces for controlling interactive TV and media management have typically been designed for the desktop and laptop experience, using conventional input devices like a trackpad, mouse and keyboard. These techniques are difficult to reconcile with the typical TV viewing experience. We designed an experiment to test a representative interactive TV interface with a number of emerging input technologies like the Nintendo Wiimote, Microsoft Kinect and tablet applications. We measured user performance with these devices while encumbered by a beverage and plate of food in order to simulate a living room experience. We found that while most of these technologies are suitable for navigating an Interactive TV experience, their use challenges us to rethink the user experience, and places limitations on things like button size and placement, as well as the types of UI widgets we can use. We hope these guidelines and heuristics will help in the design of future interactive TV experiences, as well as the development of novel interaction techniques for the TV viewing experience

Human Factors Guidance for the Use of Handheld, Portable, and Wearable Computing Devices

This report provides human factors guidance for the selection and use of handheld, portable, and wearable computing devices, including personal digital assistants (PDAs), tablet computers, and, to a more limited extent, head-mounted display systems. These devices are becoming more common in the workplace. The Federal Aviation Administration (FAA) wanted to know if these devices would be beneficial to maintenance specialists. Human factors researchers from the William J. Hughes Technical Center were asked to identify the advantages and disadvantages of these devices. These systems require different usage guidelines than standard desktop computing systems because of their size, portability, human-computer interface (HCI) designs, and intended work environments. In this report, we discuss differences between different maintenance tasks and how these differences may affect the selection of an appropriate device. We summarize the advantages and disadvantages of common handheld, portable, and wearable systems, specifically focusing on areas such as device size, screen size and resolution, input method, one- or two-handed operation, and headsdown time

An investigation into gaze-based interaction techniques for people with motor impairments

The use of eye movements to interact with computers offers opportunities for people with impaired motor ability to overcome the difficulties they often face using hand-held input devices. Computer games have become a major form of entertainment, and also provide opportunities for social interaction in multi-player environments. Games are also being used increasingly in education to motivate and engage young people. It is important that young people with motor impairments are able to benefit from, and enjoy, them. This thesis describes a program of research conducted over a 20-year period starting in the early 1990's that has investigated interaction techniques based on gaze position intended for use by people with motor impairments. The work investigates how to make standard software applications accessible by gaze, so that no particular modification to the application is needed. The work divides into 3 phases. In the first phase, ways of using gaze to interact with the graphical user interfaces of office applications were investigated, designed around the limitations of gaze interaction. Of these, overcoming the inherent inaccuracies of pointing by gaze at on-screen targets was particularly important. In the second phase, the focus shifted from office applications towards immersive games and on-line virtual worlds. Different means of using gaze position and patterns of eye movements, or gaze gestures, to issue commands were studied. Most of the testing and evaluation studies in this, like the first, used participants without motor-impairments. The third phase of the work then studied the applicability of the research findings thus far to groups of people with motor impairments, and in particular,the means of adapting the interaction techniques to individual abilities. In summary, the research has shown that collections of specialised gaze-based interaction techniques can be built as an effective means of completing the tasks in specific types of games and how these can be adapted to the differing abilities of individuals with motor impairments