Skilled Typists Research Articles

Skill-level based examination of forearm muscle activation associated with efficient wrist and finger movements during typing

This study aims to elucidate the relationship between the wrist and finger movements and forearm muscle activation of twelve young people (age: 21.1 ± 0.76 years, nine men and three women) with different typing skills. We hypothesize that skilled typists (STs) could move their wrist and finger joints faster than unskilled typists (UTs) because they could efficiently use their muscles according to the activity characteristics of the flexors and extensors of the wrist joint. We measured wrist and finger movements using a 3D motion capture system and forearm muscle activation using surface electromyography during the typing task. We analyzed the entire task and the time when the U key was entered during the same task. The angular velocity of the wrist and finger flexion/extension and the muscle activation of the wrist flexors was higher in the STs than in the UTs, while the muscle activation of the wrist extensors was higher in the latter than that in the former. Our results showed that STs may have used their forearm muscles to take advantage of the physical characteristics of the keys and the spring characteristics of their muscles and tendons. It was suggested that they placed less mechanical stress on their finger muscles and tendons when pressing and releasing the keys.

Reducing Proactive Interference in Motor Tasks

Changing automatized movement patterns often leads to initial performance decrements caused by proactive interference. In this study, we scrutinized whether proactive interference could be reduced by inhibiting the to-be-changed movement pattern by means of a physical movement constraint and verbal inhibition instructions, and whether any of the two interventions may be superior. Skilled typists typed short texts as fast and accurately as possible on a regular QWERTZ keyboard. After baseline measures, a new rule prohibiting the use of the left index finger was introduced. Subsequently, participants took part in either a verbal instruction or an additional motor restriction intervention phase. Results revealed that the original rule change was successful in inducing proactive interference in skilled typists. Most importantly, the two interventions similarly reduced proactive interference both immediately following the rule change and after ten practice sessions. We conclude that reducing proactive interference by means of physical motor restrictions and verbal instructions may be equally effective.

Designing Hand Pose Aware Virtual Keyboard With Hand Drift Tolerance

An unintentional hand drift adversely affects the typing performance of conventional virtual keyboards. To overcome this, we proposed to utilize the typing patterns of skilled typists. First, as most typists enter the keys in the same column with a predetermined finger only, we restricted these keys to be typed by their corresponding fingers. Second, our investigation of skilled typists demonstrated that hand poses vary when the typists touch different keys. Thus, rather than locating the touch point as in the case of existing virtual keyboards, we attempted to use unique hand poses to infer the target key. Based on these two techniques, we implemented a novel hand poses aware virtual keyboard that is tolerant of hand drift. Our experimental studies yielded the following results: 1) most of the QWERTY-familiar typists who have varying typing habits were easily adaptable to the proposed keyboard design and 2) the proposed keyboard outperformed existing virtual keyboards in terms of typing speed and several error rates, and eventually achieved a typing speed of approximately 56 WPM.

Typing Style and the Use of Different Sources of Information during Typing: An Investigation Using Self-Reports.

We investigated to what extent different sources of information are used in typing on a computer keyboard. Using self-reports 10 finger typists and idiosyncratic typists estimated how much attention they pay to different sources of information during copy typing and free typing and how much they use them for error detection. 10 finger typists reported less attention to the keyboard and the fingers and more attention to the template and the screen than idiosyncratic typists. The groups did not differ in attention to touch/kinaesthesis in copy typing and free typing, but 10 finger typists reported more use of touch/kinaesthesis in error detection. This indicates that processing of tactile/kinaesthetic information may occur largely outside conscious control, as long as no errors occur. 10 finger typists reported more use of internal prediction of movement consequences for error detection than idiosyncratic typists, reflecting more precise internal models. Further in copy typing compared to free typing attention to the template is required, thus leaving less attentional capacity for other sources of information. Correlations showed that higher skilled typists, regardless of typing style, rely more on sources of information which are usually associated with 10 finger typing. One limitation of the study is that only self-reports were used. We conclude that typing task, typing proficiency, and typing style influence how attention is distributed during typing.

Pushing typists back on the learning curve: Revealing chunking in skilled typewriting.

Theories of skilled performance propose that highly trained skills involve hierarchically structured control processes. The present study examined and demonstrated hierarchical control at several levels of processing in skilled typewriting. In the first two experiments, we scrambled the order of letters in words to prevent skilled typists from chunking letters, and compared typing words and scrambled words. Experiment 1 manipulated stimulus quality to reveal chunking in perception, and Experiment 2 manipulated concurrent memory load to reveal chunking in short-term memory (STM). Both experiments manipulated the number of letters in words and nonwords to reveal chunking in motor planning. In the next two experiments, we degraded typing skill by altering the usual haptic feedback by using a laser-projection keyboard, so that typists had to monitor keystrokes. Neither the number of motor chunks (Experiment 3) nor the number of STM items (Experiment 4) was influenced by the manipulation. The results indicate that the utilization of hierarchical control depends on whether the input allows chunking but not on whether the output is generated automatically. We consider the role of automaticity in hierarchical control of skilled performance.

What skilled typists don’t know about the QWERTY keyboard

We conducted four experiments to investigate skilled typists' explicit knowledge of the locations of keys on the QWERTY keyboard, with three procedures: free recall (Exp. 1), cued recall (Exp. 2), and recognition (Exp. 3). We found that skilled typists' explicit knowledge of key locations is incomplete and inaccurate. The findings are consistent with theories of skilled performance and automaticity that associate implicit knowledge with skilled performance and explicit knowledge with novice performance. In Experiment 4, we investigated whether novice typists acquire more complete explicit knowledge of key locations when learning to touch-type. We had skilled QWERTY typists complete a Dvorak touch-typing tutorial. We then tested their explicit knowledge of the Dvorak and QWERTY key locations with the free recall task. We found no difference in explicit knowledge of the two keyboards, suggesting that typists know little about key locations on the keyboard, whether they are exposed to the keyboard for 2h or 12years.

Prevention and correction in post-error performance: An ounce of prevention, a pound of cure.

Error detection serves 2 different functions: prevention and cure. Prevention engages post-error slowing to reduce future errors, whereas cure engages processes that correct the error. Thus, prevention predicts post-error slowing, and cure does not. We investigated this distinction in skilled typists in 3 experiments. In Experiment 1, post-error performance was investigated in 800 typists who completed a short continuous typing test where correction was disallowed. In Experiments 2 and 3, post-error performance and post-correction performance were investigated by manipulating whether typists were allowed to correct their mistakes. Across experiments, there was limited evidence that typists used error detection for prevention; typists preferred the cure. After making mistakes, they corrected them and rapidly resumed typing at normal rates. Post-error slowing occurred only when correction was disabled; post-error speeding occurred when correction was enabled. This finding offers support for the novel hypothesis that post-error slowing reflects the inhibition of pre-potent tendencies to correct mistakes. Error-detection processes in general will be better understood by distinguishing between tasks that allow performers to cure their errors through correction rather than reduce their errors through prevention.

Japanese skilled typists without solid representation on keyboard layout

Japanese skilled typists without solid representation on keyboard layout

Performance of Skilled Typists as a Function of Pacing, Response Complexity and Urgency in Numerical Hear-and-type Tasks

Performance of skilled typists in numerical hear-and-type tasks, i.e. making immediate keypresses in response to verbally presented numbers, has practical and theoretical importance because it help understand perceptual-motor skills and error mechanisms. Effects of speech rates (500ms vs. 1000ms interval), urgency (elicited by monetary rewards) and finger strategies (single vs. multi-finger typing) on typing speed and accuracy were investigated. Fast speech rate and multi-finger typing degraded both typing speed and accuracy, while urgency improved typing speed at the expense of decreasing accuracy. Errors were almost doubled under urgent condition while urgency effect on speed was similar to that of speech rate. The results implied that common beliefs of fast speech and multi-finger typing being incentive to typing performance might not be true, and internalized urgency could play a more important role in error-making than external task demands.

Electrophysiological Evidence for Parallel Response Selection in Skilled Typists

Electrophysiological Evidence for Parallel Response Selection in Skilled Typists

Cognitive Illusions of Authorship Reveal Hierarchical Error Detection in Skilled Typists

The ability to detect errors is an essential component of cognitive control. Studies of error detection in humans typically use simple tasks and propose single-process theories of detection. We examined error detection by skilled typists and found illusions of authorship that provide evidence for two error-detection processes. We corrected errors that typists made and inserted errors in correct responses. When asked to report errors, typists took credit for corrected errors and accepted blame for inserted errors, claiming authorship for the appearance of the screen. However, their typing rate showed no evidence of these illusions, slowing down after corrected errors but not after inserted errors. This dissociation suggests two error-detection processes: one sensitive to the appearance of the screen and the other sensitive to keystrokes.

Do you know where your fingers have been? Explicit knowledge of the spatial layout of the keyboard in skilled typists

Two experiments evaluated skilled typists' ability to report knowledge about the layout of keys on a standard keyboard. In Experiment 1, subjects judged the relative direction of letters on the computer keyboard. One group of subjects was asked to imagine the keyboard, one group was allowed to look at the keyboard, and one group was asked to type the letter pair before judging relative direction. The imagine group had larger angular error and longer response time than both the look and touch groups. In Experiment 2, subjects placed one key relative to another. Again, the imagine group had larger angular error, larger distance error, and longer response time than the other groups. The two experiments suggest that skilled typists have poor explicit knowledge of key locations. The results are interpreted in terms of a model with two hierarchical parts in the system controlling typewriting.

Embodied memory judgments: A case of motor fluency.

It is well known that perceptual and conceptual fluency can influence episodic memory judgments. Here, the authors asked whether fluency arising from the motor system also impacts recognition memory. Past research has shown that the perception of letters automatically activates motor programs of typing actions in skilled typists. In this study, expert typists made more false recognition errors to letter dyads which would be easier or more fluent to type than nonfluent dyads, while no typing action was involved (Experiment 1). This effect was minimized with a secondary motor task that implicated the same fingers that would be used to type the presented dyads, but this effect remained with a noninterfering motor task (Experiment 2). Typing novices, as a comparison group, did not show fluency effects in recognition memory. These findings suggest that memory is influenced by covert simulation of actions associated with the items being judged-even when there is no intention to act-and highlight the intimate connections between higher level cognition and action.

Temporal Change in Bimanual Interkeypress Intervals and Self-Reported Symptoms During Continuous Typing

Continuous typing is likely to induce mental and/or muscular fatigue, which contributes to musculoskeletal discomfort. Our goals were to describe the temporal changes in symptoms and interkeypress intervals (IKIs) of each hand during continuous typing. The effects of demographic characteristics and time on the IKI were examined. Twenty-four healthy and skilled typists volunteered to participate in this repeated-measurement study. All the subjects typed an English text for 90 min in the laboratory. The outcomes included self-reported pain and fatigue, average typing speed, accuracy rate, finger tapping speed, and IKIs as recorded by electronic activity monitoring software (VDTlog). The changes in self-reported symptoms, average typing speed and accuracy rate after 90 min of typing were compared with baseline data by paired testing. The effects of demographic characteristics and time on IKIs of both hands were explored by generalized estimate equation (GEE) analysis. The pain and fatigue ratings of the study subjects were significantly higher after 60 and 90 min of typing, but the average typing speed of every 30 min remained similar. The most common complaints were associated with the eyes, upper back and wrists. The IKIs as recorded by VDTlog was associated with typing speed. Furthermore, GEE analysis showed that the IKI of the right hand was the shortest in the last 10 min throughout the experiment, while left-hand typing exhibited the longest IKI during the last 10 min of each 30-min typing session. Time has different effect on the temporal changes of IKI during continuous typing for the left and right hands. Right-hand IKI tends to be shorter by time, especially at the last 10 min of typing, while left-hand IKI prolongs as typing continues for 30 min. Perceived pain and fatigue is apparent after continuous typing, though no change in average typing speed is observed.

새로운 입력장치 개발을 위한 숙련자의 타이핑 동작에 관한 실험적 연구

A virtual keyboard may be efficient as a new mobile input device supporting QWERTY keyboard layout. As a preliminary study for developing a virtual keyboard, the typing pattern of a skilled human is investigated. In the study the touch-positions of the fingers are measured with a touchscreen while five skilled typists perform typing of long sentences. From these measurements it can be observed that the groups of touch-positions are classified into alphabetic characters. Though there are some mismatches, we can find constant distances capable of being discriminated among the groups. Based on the analysis the prediction algorithm of the constant distance is proposed and evaluated, which is useful for realization of a portable virtual keyboard.

Age and skill differences in typing related and unrelated reaction time tasks

Abstract Sixty-five typists ranging in age from 21-68 years and in skill from 28-91 net words/minute participated in an experiment examining age-related differences in motor performance. Two tasks were employed, digraph typing and choice reaction time, which assessed the latencies to type two consecutive keystrokes. the results for both tasks replicated results reported by Bosman (1993) suggesting that low skill older typists exhibit a deficit in both the translation and execution components of motor performance, whereas high skill older typists exhibit a deficit in translation only. the generalizability of typing-related experience to a novel task was assessed by examining the effect of typing skill on choice reaction time performance. the results indicated that skilled typists were not advantaged for translation. However, skilled typists were advantaged for execution, and the benefit of skill was greatest for older typists.

Key Force and Typing Performance

The IBM Design Center in Boca Raton studied the operating-point key force for a portable computer keyboard. Alden, Daniels, and Kanarick (1972) report that typists prefer operating-point key forces of between 25 and 150 grams. We compared different key forces that fell within the range recommended by Alden et al. The only difference between the keyboards we studied was the amount of force required to activate the keys. The first keyboard (58 keyboard) required 58 grams of force to activate the keys. The second keyboard (74 keyboard) required 74 grams of force to activate the keys. Sixteen skilled typists used both keyboards to enter text. Input speed was significantly faster on the 58–gram keyboard. A significant number of typists preferred the 58-gram keyboard. The results suggest that the optimal key force for portable computer keyboards is less than 74 grams.

Perceptual, cognitive, and motoric aspects of transcription typing.

Recent research findings in the domain of transcription typing are reviewed in the context of a fourcomponent heuristic model. The four components consist of an input phase in which to-be-typed text is grouped into familiar chunks, a parsing phase in which the chunks are decomposed into discrete characters, a translation phase in which characters are converted into movement specifications, and finally an execution phase in which the actual movements are produced. This framework was used to integrate 29 distinct empirical phenomena related to transcription typing, including the multiple units of typing, the existence of four major categories of errors, and differences associated with i ncreasi ng skill. The review concludes with a brief discussion of several issues that appear to provide promising directions for future research. Transcription typing has many advantages over alternative forms of activity for the purpose of analyzing human skilled behavior. First, the number of practitioners is extremely large, making it relatively easy to locate moderately sized samples of individuals at many levels of expertise. Second, although the performance of skilled typists appears continuous, typing behavior is naturally partitioned into discrete and easily measured keystroke responses. Third, despite its seeming simplicity, transcription typing involves an intricate and complex interaction of perceptual, cognitive, and motoric processes. Not only does verbal material have to be registered and perceived, but it has to be appropriately partitioned, accurately translated into physical movements, and then those movements executed at rates exceeding several hundred keystrokes per minute. A thorough understanding of a task involving such precise and rapid coordination of diverse processes will surely contribute to greater knowledge about the nature of highly skilled performance in a wide range of cognitive activities. In an earlier article (Salthouse, 1984a), a composite model of transcription typing was briefly outlined to provide a framework for localizing the effects associated with the age and skill level of the typist. Most of the properties of the model were derived from ideas introduced by earlier theorists (e.g., Cooper, 1983; Logan, 1983; Rumelhart& Norman, 1982; Shaffer, 1973, 1975a, 1976; Shaffer & Hardwick, 1970; Thomas & Jones, 1970), and thus it can be viewed as a synthesis of many previous proposals. The goal of the present article is to use that model as a heuristic device to help organize a review of the empirical literature concerned with transcription typing. Figure I illustrates the major components of the model, and the primary operations presumed

Identification of Skilled Typists

Skilled typists are less likely to show idiosyncratic patterns of capitalization, punctuation and spelling and are thus more difficult to identify than self-taught typists. However, categorization of the ordinary, single-letter errors made by all typists reveals differences in the error patterns among skilled typists. Initially, these errors are classified as letter insertions, omissions, substitutions and transpositions. The distribution of errors across these categories varies widely from one typist to another. Further subdividing of these categories is outlined. This approach may aid in screening possible typists of questioned documents, and possibly a similar taxonomy of handwriting errors may assist in identifying the source.

Simulating a skilled typist: a study of skilled cognitive-motor performance

We review the major phenomena of skilled typing and propose a model for the control of the hands and fingers during typing. The model is based upon an Activation-Trigger-Schema system in which a hierarchical structure of schemata directs the selection of the letters to be typed and, then, controls the hand and finger movements by a cooperative, relaxation algorithm. The interactions of the patterns of activation and inhibition among the schemata determine the temporal ordering for launching the keystrokes. To account for the phenomena of doubling errors, the model has only “type” schemata—no “token” schemata—with only a weak binding between the special schema that signals a doubling, and its argument. The model exists as a working computer simulation and produces an output display of the hands and fingers moving over the keyboard. It reproduces some of the major phenomena of typing, including the interkeystroke interval times, the pattern of transposition errors found in skilled typists, and doubling errors. Although the model is clearly inadequate or wrong in some of its features and assumptions, it serves as a useful first approximation for the understanding of skilled typing.