diff --git a/acknowledgments.tex b/acknowledgments.tex index f803ec8..0345386 100644 --- a/acknowledgments.tex +++ b/acknowledgments.tex @@ -1,4 +1,4 @@ %----------Danksagung/Acknowledgments-------------------------------------------------------------- \addsec{Acknowledgments} -Helo +Hello (: diff --git a/chap1/introduction.tex b/chap1/introduction.tex index ed8be1d..231bc15 100644 --- a/chap1/introduction.tex +++ b/chap1/introduction.tex @@ -1,48 +1,51 @@ -\subsection{Motivation} -In recent years, computers are used to some extend in almost every industry in -Europe \cite{eurostat_ent_w_comp} and China \cite{iresearch_ent_w_comp}. This -leads to the conclusion, that also other countries must have a high usage of -computers in corporations. Furthermore, according to a statistic published by -\citeauthor{itu_hh_w_comp} in 2019, nearly half of the worldwide households have -access to at least one computer \cite{itu_hh_w_comp}. One of the most used -devices for data input while operating a computer is the keyboard -\parencite[22]{handbook_chi}. Therefore, people who use a computer, either at -home or to fulfill certain tasks at work, are also likely to use a keyboard. An -important part of a keyboard is the keyswitch also called keyboard key or -key. Those keyswitches use, depending on the manufacturer or keyboard type, -different mechanisms to actuate a keypress. More commonly used mechanism to date -are scissor switches, mostly used in laptop keyboards, rubber dome and membrane switches, -often used in low- to mid-priced keyboards, and mechanical switches which are -the main switch type for high-end and gaming keyboards -\cite{ergopedia_keyswitch}. Depending on the mechanism and type of key used, it -is possible that different force has to be applied to the key to activate -it. Normally, the force required to activate a key is identical for each key -across the keyboard. However, previous research has shown, that there is a -disparity in force generated by different fingers -\cite{bretz_finger_force}. This raises the question, why there are no keyboards -for personal or work related use cases with adjusted actuation forces per finger -or even customizable keyboards, where an individual can select the actuation -force for each keyswitch individually. - -In recent decades, computers and other electronic devices have become an -indispensable part of everyday life. Computers are used in almost every industry -\cite{iresearch_ent_w_comp, eurostat_ent_w_comp} and almost half of the -worldwide households have access to at least one computer \cite{itu_hh_w_comp}. -Even 153 years after the first typewriter was patented \cite{noyes_qwerty, } -people still use keyboards as their main way to input data into a computer -\parencite[22]{handbook_chi}, \cite{broel_dektop_or_smartphone}. A potential -problem while interacting with a computer through the usage of a keyboard are -rapid movements of the fingers over a prolonged time. - -Input tasks are not only restricted to pure data entry but also include complex -inputs required by games. - - -Prolonged usage of computers can lead to serious diseases - - - -With the rising popularity of smartphones and other touchscreen devices -\cite{gs_statcounter_dmt_2020} which utilize virtual keyboards to fulfill a -variety of tasks that also include data entry, e.g., writing text messages, -short emails, communicating on social media or web browsing +\section{Motivation} +\label{sec:label} + + +% In recent years, computers are used to some extend in almost every industry in +% Europe \cite{eurostat_ent_w_comp} and China \cite{iresearch_ent_w_comp}. This +% leads to the conclusion, that also other countries must have a high usage of +% computers in corporations. Furthermore, according to a statistic published by +% \citeauthor{itu_hh_w_comp} in 2019, nearly half of the worldwide households have +% access to at least one computer \cite{itu_hh_w_comp}. One of the most used +% devices for data input while operating a computer is the keyboard +% \parencite[22]{handbook_chi}. Therefore, people who use a computer, either at +% home or to fulfill certain tasks at work, are also likely to use a keyboard. An +% important part of a keyboard is the keyswitch also called keyboard key or +% key. Those keyswitches use, depending on the manufacturer or keyboard type, +% different mechanisms to actuate a keypress. More commonly used mechanism to date +% are scissor switches, mostly used in laptop keyboards, rubber dome and membrane switches, +% often used in low- to mid-priced keyboards, and mechanical switches which are +% the main switch type for high-end and gaming keyboards +% \cite{ergopedia_keyswitch}. Depending on the mechanism and type of key used, it +% is possible that different force has to be applied to the key to activate +% it. Normally, the force required to activate a key is identical for each key +% across the keyboard. However, previous research has shown, that there is a +% disparity in force generated by different fingers +% \cite{bretz_finger_force}. This raises the question, why there are no keyboards +% for personal or work related use cases with adjusted actuation forces per finger +% or even customizable keyboards, where an individual can select the actuation +% force for each keyswitch individually. + +% In recent decades, computers and other electronic devices have become an +% indispensable part of everyday life. Computers are used in almost every industry +% \cite{iresearch_ent_w_comp, eurostat_ent_w_comp} and almost half of the +% worldwide households have access to at least one computer \cite{itu_hh_w_comp}. +% Even 153 years after the first typewriter was patented \cite{noyes_qwerty, } +% people still use keyboards as their main way to input data into a computer +% \parencite[22]{handbook_chi}, \cite{broel_dektop_or_smartphone}. A potential +% problem while interacting with a computer through the usage of a keyboard are +% rapid movements of the fingers over a prolonged time. + +% Input tasks are not only restricted to pure data entry but also include complex +% inputs required by games. + + +% Prolonged usage of computers can lead to serious diseases + + + +% With the rising popularity of smartphones and other touchscreen devices +% \cite{gs_statcounter_dmt_2020} which utilize virtual keyboards to fulfill a +% variety of tasks that also include data entry, e.g., writing text messages, +% short emails, communicating on social media or web browsing diff --git a/chap2/literature_review.tex b/chap2/literature_review.tex index 641a9ea..360ef4e 100644 --- a/chap2/literature_review.tex +++ b/chap2/literature_review.tex @@ -1,59 +1,79 @@ \section{Literature Review} -To better understand which metrics and methods are meaningful in the domain of keyboards and especially when +% To better understand which metrics and methods are meaningful in the domain of keyboards and especially when -To investigate whether or not solely the actuation force of individual keys can make a difference in terms of efficiency or satisfaction an .... +% To investigate whether or not solely the actuation force of individual keys can make a difference in terms of efficiency or satisfaction an .... \subsection{Keyboards and key switches} +\begin{figure}[ht] + \centering + \includegraphics[width=1.0\textwidth]{images/keyboard_models.jpg} + \caption{Different keyboard models} + \label{fig:keyboard_models} +\end{figure} + Keyboards are well known input devices used to operate a computer. There are a variety of keyboard types and models available on the market, some of which can be seen in Figure \ref{fig:keyboard_models}. The obvious difference between those keyboards in Figure \ref{fig:keyboard_models} is their general -appearance. What we see is mainly the general shape of the enclosure and the -keycaps, which are the rectangular pieces of plastic on top of the actual -keyswitches which indicate which letter, number or symbol, also known as +appearance. What we see is mainly the shape of the enclosure and the keycaps, +which are the rectangular pieces of plastic on top of the actual keyswitches +which sometimes indicate which letter, number or symbol, also known as characters, a keypress should send to the computer. These keycaps are mainly -made out of the two plastics \gls{ABS} and \gls{PBT} which mainly differ in -feel, durability, cost and sound \parencite[8]{bassett_keycap}. Nowadays, there -are three main standards for the physical layout of keyboards namely ISO/IEC -9995 \cite{iso9995-2}, ANSI-INCITS 154-1988 \cite{ansi-incits-154-1988} and JIS -X 6002-1980 \cite{jis-x-6002-1980}, that propose slightly different arrangements -of the keys and some even alter the shape of a few keys. Figure -TODO\ref{fig:keyboard_ISO_ANSI_JSP} shows the layouts defined by the three -standards mentioned and shows the main differences. In addition to the physical -layout, there are also various layouts concerning the mapping of the physical -key to a character that is displayed by the computer. Most of the time, the -mapping happens on the computer via software and therefore the choice of layout -is not necessarily restricted by the physical layout of the keyboard but rather -a personal preference. As seen in Figure TODO \ref{fig:keyboard_models}, there -are also non standard physical layouts available which are often designed to -improve the posture of the upper extremity while typing to reduce the risk of -injury or even assist in recovering from previous \gls{WRUED} -\cite{ripat_ergo}. Those designs often split the keyboard in two halves to -reduce ulnar deviation and some designs also allow tenting of the halves or -provide a fixed tent which also reduces forearm pronation \cite{baker_ergo, - rempel_ergo}. Besides the exterior design of the keyboard, there is another -part of interest—the keyswitch. This component of a keyboard actually sends the -signal that a key is pressed down. There are different types of keyswitches -available to date. The more commonly available ones are scissor switches and -rubber dome switches which are both subsets of the membrane switches. Scissor -switches are often found in keyboards that are integrated into notebooks while -rubber dome switches are mostly used in workplace keyboards. Both variants use a -rubber membrane with small domes underneath each key. When a key is pressed, the -corresponding dome collapses and because the dome's inner wall is coated with a -conductive material, closes an electrical circuit \cite{ergopedia_keyswitch, - peery_3d_keyswitch}. Another type of switches are mechanical -keyswitches. These switches are frequently used in gaming and high quality -workplace keyboards as well as by enthusiast along with prosumers which build -and then sell custom made keyboards to the latter audience \cite{bassett_keycap, - ergopedia_keyswitch}. These keyswitches are composed of several mechanical -parts which can be examined in Figure TODO\ref{fig:mech_keyswitch_dissas}. The -housing is made up of two parts, the bottom and top shell. The actual mechanism -consists of two conductive plates, which when connected trigger a keypress, a -stainless steel spring which defines how much force has to be applied to the -switch to activate it and a stem which sits on top of the spring and separates -the two plates. When pressure is applied to the keycap, which is connected to -the stem, the spring gets contracted and the stem moves downwards and thereby -stops separating the two plates which closes the electrical circuit and sends a +made out of the two plastics \gls{ABS} and \gls{PBT} which primarily differ in +feel, durability, cost and sound \parencite[8]{bassett_keycap}. + +\begin{figure}[ht] + \centering + \includegraphics[width=1.0\textwidth]{images/keyboard_layouts.png} + \caption{The three major physical keyboard layouts all labeled with the + alphanumeric characters of the most popular layout―\gls{QWERTY} + \cite{wiki_kb_layouts}} + \label{fig:keyboard_layouts} +\end{figure} + +Nowadays, there are three main standards for the physical layout of keyboards +namely ISO/IEC 9995 \cite{iso9995-2}, ANSI-INCITS 154-1988 +\cite{ansi-incits-154-1988} and JIS X 6002-1980 \cite{jis-x-6002-1980}, that +propose slightly different arrangements of the keys and some even alter the +shape of a few keys. Figure TODO\ref{fig:keyboard_layouts} shows the layouts +defined by the three standards mentioned and shows the main differences. In +addition to the physical layout, there are also various layouts concerning the +mapping of the physical key to a character that is displayed by the +computer. Most of the time, the mapping happens on the computer via software and +therefore the choice of layout is not necessarily restricted by the physical +layout of the keyboard but rather a personal preference. As seen in Figure +\ref{fig:keyboard_models}, there are also non standard physical layouts +available which are often designed to improve the posture of the upper extremity +while typing to reduce the risk of injury or even assist in recovering from +previous \gls{WRUED} \cite{ripat_ergo}. Those designs often split the keyboard +in two halves to reduce ulnar deviation and some designs also allow tenting of +the halves or provide a fixed tent which also reduces forearm pronation +\cite{baker_ergo, rempel_ergo}. Besides the exterior design of the keyboard, +there is another part of interest—the keyswitch. This component of a keyboard +actually sends the signal that a key is pressed. There are different types of +keyswitches available to date. The more commonly available ones are scissor +switches and rubber dome switches which are both subsets of the membrane +switches. Scissor switches are often found in keyboards that are integrated into +notebooks while rubber dome switches are mostly used in workplace +keyboards. Both variants use a rubber membrane with small domes underneath each +key. When a key is pressed, the corresponding dome collapses and because the +dome's inner wall is coated with a conductive material, closes an electrical +circuit \cite{ergopedia_keyswitch, peery_3d_keyswitch}. Another type of switches +are mechanical keyswitches. These switches are frequently used in gaming and +high quality workplace keyboards as well as by enthusiast along with prosumers +which build and then sell custom made keyboards to the latter audience +\cite{bassett_keycap, ergopedia_keyswitch}. These keyswitches are composed of +several mechanical parts which can be examined in Figure +\ref{fig:mech_keyswitches_dissas}. The housing is made up of two parts, the +bottom and top shell. The actual mechanism consists of two conductive plates, +which when connected trigger a keypress, a stainless steel spring which defines +how much force has to be applied to the switch to activate it and a stem which +sits on top of the spring and separates the two plates. The shape of the stem, +represented by the enlarged red lines in Figure +\ref{fig:mech_keyswitches_dissas}, defines the haptic feedback produced by the +keyswitch. When pressure is applied to the keycap, which is connected to the +stem, the spring gets contracted and the stem moves downwards and thereby stops +separating the two plates which closes the electrical circuit and sends a keypress to the computer. After the key is released, the spring pushes the stem back to its original position \cite{bassett_keycap, peery_3d_keyswitch, ergopedia_keyswitch, chen_mech_switch}. Usually, mechanical keyswitches are @@ -63,15 +83,25 @@ be hot-swapped without soldering at all \cite{gmmk_hot_swap}. It is also possible to equip an already existing \gls{PCB} with sockets to make it hot-swappable \cite{te_connect}. +\begin{figure}[ht] + \centering + \includegraphics[width=1.0\textwidth]{images/mech_keyswitches_dissas.jpg} + \caption{Disassembled tactile, clicky and linear mechanical keyswitchs. The + red lines resemble the shape of the stem which is responsible for the haptic + feedback and thus, in combination with the strength of the spring, the + required actuation force} + \label{fig:mech_keyswitches_dissas} +\end{figure} + Mechanical keyswitches also have three main subcategories. Those categories primarily define if and how feedback for a keypress is realised: \begin{enumerate} \item \textbf{Tactile Switches} utilize a small bump on the stem to slightly - increase the force required immediately before and a collapse of force right - after the actual actuation happens. This provides the typist with a short - noticeable haptic feedback and which should encourage a premature release of - the key. An early study by Brunner and Richardson suggested, that this - feedback leads to faster typing speeds and a lower error rate in both + increase and then instantly collapse the force required immediately before the + actual actuation happens \cite{cherry_mx_brown}. This provides the typist with + a short noticeable haptic feedback and which should encourage a premature + release of the key. An early study by Brunner and Richardson suggested, that + this feedback leads to faster typing speeds and a lower error rate in both experienced and casual typists (n=24) \cite{brunner_keyswitch}. Contrary, a study by Akagi yielded no significant differences in terms of speed and error rate between tactile and linear keyswitches and links the variation found in @@ -81,29 +111,41 @@ primarily define if and how feedback for a keypress is realised: \item \textbf{Tactile and audible Switches (Clicky)} separate the stem into two parts, the lower part also features a small bump to provide tactile feedback and is also responsible for a distinct click sound when the actuation - happens. Gerard et al. noted, that in their study (n=24), keyboards with - audible feedback increased typing speed and decreased typing force. This - improvement could have been due to the previous experience of participants - with keyboards of similar model and keyswitch characteristic + happens \cite{cherry_mx_blue}. Gerard et al. noted, that in their study + (n=24), keyboards with audible feedback increased typing speed and decreased + typing force. This improvement could have been due to the previous experience + of participants with keyboards of similar model and keyswitch characteristic \cite{gerard_keyswitch}. \item \textbf{Linear Switches} do not offer a distinct feedback for the typist. The activation of the keyswitch just happens after approximately half - the total travel distance. The only tactile feedback that could happen is the - impact of \gls{bottoming}, but with enough practice, typist can develop a - lighter touch which reduces overall typing force and therefore reduces the - risk of \gls{WRUED} \cite{gerard_keyswitch, peery_3d_keyswitch, fagarasanu_force_training}. + the total travel distance \cite{cherry_mx_red}. The only tactile feedback that + could happen is the impact of \gls{bottoming}, but with enough practice, + typist can develop a lighter touch which reduces overall typing force and + therefore reduces the risk of \gls{WRUED} \cite{gerard_keyswitch, + peery_3d_keyswitch, fagarasanu_force_training}. \end{enumerate} The corresponding force-displacement curves for one exemplary keyswitch of each -category are shown in Figure TODO\ref{fig:ks_fd_curves}. +category by the manufacturer Cherry are shown in Figure +\ref{fig:ks_fd_curves}. The Operational position indicates the activation of the +keyswitch. + +\begin{figure}[ht] + \centering + \includegraphics[width=1.0\textwidth]{images/ks_fd_curves.jpg} + \caption{Actuation graphs for Cherry MX BROWN \cite{cherry_mx_brown} | BLUE + \cite{cherry_mx_blue} | RED \cite{cherry_mx_red} switches. Tactile position marks the point where a haptic feedback happens, operational position marks the activation of the keyswitch and reset position is the point where the keyswitch deactivates again} + \label{fig:ks_fd_curves} +\end{figure} + All types of keyswitches mentioned so far are available in a myriad of actuation forces. Actuation force, also sometimes referred to as make force, is the force required to activate the keyswitch \cite{radwin_keyswitch, ergopedia_keyswitch}. That means depending on the mechanism used, activation -describes the closing of an electrical circuit which then forwards a signal, -that is then processed by a controller inside of the keyboard and then forwarded -to the computer. The computer then registers the character depending on the +describes the closing of an electrical circuit which forwards a signal, that is +then processed by a controller inside of the keyboard and finally send to the +computer. The computer then selects the corresponding character depending on the layout used by the user. Previous studies have shown, that actuation force has an impact on error rate, subjective discomfort, muscle activity and force applied by the typist \cite{akagi_keyswitch, gerard_keyswitch, @@ -144,23 +186,200 @@ capabilities for our experiment to reduce the effort required to equip each keyboard with the required keyswitches and in case a keyswitch fails during the experiment, decrease the time required to replace the faulty switch. -\subsection{Measurement of keyboard related metrics} -A common way to compare different methods concerning alphanumeric input in terms -of efficiency is to use one of many typing test applications which are -commercially available. Depending on the software used and the experimental -setup, users have to input different kinds of text, either for a predefined time -or the time is measured till the whole text is transcribed \cite{chen_typing_test}. +\subsection{Measurement of typing related metrics} +\label{sec:metrics} +Nowadays, a common way to compare different methods concerning alphanumeric +input in terms of efficiency is to use one of many typing test or word +processing applications which are commercially available. Depending on the +software used and the experimental setup, users have to input different kinds of +text, either for a predefined time or the time is measured till the whole text +is transcribed \cite{chen_typing_test, hoffmann_typeright, + fagarasanu_force_training, akagi_keyswitch, kim_typingforces, + pereira_typing_test}. Text used should be easy to read for typists +participating in studies that evaluate their performance and are therefore is +chosen based on a metric called the \gls{FRE} which indicates the +understandability of text \cite{fagarasanu_force_training, + kim_typingforces, flesch_fre}. The score ranges from 0 which implies very poor reading +ease to 100 suggesting that the style of writing used causes the text to be very +easy to comprehend \cite{flesch_fre}. Immel proposed an adjusted formula of the +\gls{FRE} that is suitable for German text \cite{immel_fre} and can be seen in +(\ref{eq:fre_german}). + +\begin{equation}\label{eq:fre_german} + FRE_{deutsch} = 180 - \underbrace{ASL}_{\mathclap{\text{Average Sentence Length}}} - (58,5 * \overbrace{ASW}^{\mathclap{\text{Average Syllables per Word}}}) +\end{equation} + +According to Flesch, the values retrieved by applying the formula to text can be +classified according to the ranges given in Table \ref{tbl:fre_ranges} \cite{flesch_fre}. +\begin{table} + + \centering + \caption{Categories for different FRE scores to classify the understandability + of text \cite{flesch_fre}} + \label{tbl:fre_ranges} + \begin{tabular}{l|c} + \hline\hline + \multicolumn{1}{c|}{FRE} & Understandability \\ + \hline + \multicolumn{1}{c|}{0 - 30} & Very difficult \\ + 30 - 50 & Difficult \\ + 50 - 60 & Fairly difficult \\ + 60 - 70 & Standard \\ + 70 - 80 & Fairly easy \\ + 80 - 90 & Easy \\ + \multicolumn{1}{r|}{90 - 100} & Very easy \\ + \hline + \end{tabular} +\end{table} + +There are several metrics to measure the performance of typists. Typical methods +to measure speed are +\begin{enumerate} + \item \textbf{\Gls{WPM}} + \begin{equation}\label{eq:wpm} + WPM = \frac{|T| - 1}{S} * 60 * \frac{1}{5} + \end{equation} + In Eq. (\ref{eq:wpm}), $|T|$ is the length of the transcribed text, $S$ the + time in seconds taken to transcribe $T$, $\frac{1}{5}$ the average word length + and $60$ the conversion to minutes. $|T| - 1$ counteracts the first input + which starts the timer in many typing tests \cite{mackenzie_metrics}. + \item \textbf{\Gls{AdjWPM}} is especially useful if participants are allowed to + make mistakes and at the same time not forced to correct them. This method adds + an adjustable factor to lower the \gls{WPM} proportionally to the uncorrected + error rate $UER := [0;1]$ defined in Eq. (\ref{eq:uer}). The exponent $a$ in + Eq. (\ref{eq:cwpm}) can be chosen depending on the desired degree of correction + \cite{mackenzie_metrics}. + \begin{equation}\label{eq:cwpm} + AdjWPM = WPM * (1 - UER)^{a} + \end{equation} + \item \textbf{\Gls{KSPS}} measures the raw input rate of a typist by capturing + the whole input stream including backspaces and deleted characters ($IS$) + \cite{mackenzie_metrics}. + + \begin{equation}\label{eq:ksps} + KSPS = \frac{|IS| - 1}{S} + \end{equation} +\end{enumerate} + +In addition to speed, the error rate of typists can be measured with the +following two methods + +\begin{enumerate} + \item \textbf{\gls{CER}} is the ratio of erroneous input that got fixed + ($IF$) to any character typed during transcription, including $IF$ + \cite{soukoreff_metrics}. + \begin{equation}\label{eq:cer} + CER = \frac{|IF|}{|T| + |IF|} + \end{equation} + + \item \textbf{\gls{UER}} is the ratio of erroneous input that was \textbf{not} + fixed ($INF$) to any character typed during transcription, including $IF$ + \cite{soukoreff_metrics}. + \begin{equation}\label{eq:uer} + UER = \frac{|INF|}{|T| + |IF|} + \end{equation} +\end{enumerate} + +In several other studies, in addition to the metrics mentioned so far, \gls{EMG} +data was captured to evaluate the muscle activity or applied force while typing +on completely different or modified hardware \cite{kim_typingforces, + fagarasanu_force_training, gerard_audio_force, gerard_keyswitch, martin_force, + rose_force, rempel_ergo, pereira_typing_test}. \gls{EMG} signals, are captured +with the help of specialized equipment that utilize electrodes which are either +placed onto the skin above the muscles of interest (non-invasive) or inserted +directly into the muscle (invasive). The disadvantage of non-invasive surface +level electrodes is the lacking capability to capture the distinct signal of one +isolated muscle \cite{reaz_emg}. Nevertheless, because this type of electrode is +more likely to find acceptance among participants and is also easier to apply by +non-medically trained researchers, it finds wide adoption among studies +\cite{takala_emg}. To make \gls{EMG} data comparable across subjects, it is +necessary to conduct initial measurements where each individual participant is +instructed to first completely relax and then fully contract (\gls{MVC}) the +muscles of interest. These values are used to normalize further data obtained in +an experimental setting. The mean signal yielded by complete relaxation is +subtracted to reduce noise and the \gls{MVC} is used to obtain the individuals +percentage of muscle activity (\%MVC or EMG\%) during tests \cite{halaki_emg, + takala_emg, rempel_ergo}. Muscles typically measured during typing exercises +are the \gls{FDS}, \gls{FDP} and \gls{ED}. The main function of the \gls{FDS} +and \gls{FDP} is the flexion of the medial four digits, while the \gls{ED} +mainly extends the medial four digits. Therefore, these muscles are primarily +involved in the finger movements required for typing on a keyboard +\cite{netter_anatomy, kim_typingforces, gerard_keyswitch, gerard_audio_force}. +A method frequently used to measure applied force is to place one or multiple +load cells under the keyboard \cite{gerard_keyswitch, rempel_ergo, + bufton_typingforces}. Load cells are electronic components that are able to +convert applied force to an electrical signal. This signal usually gets +amplified by specialized circuits and then further processed by a micro +controller, computer or other hardware \cite{johnson_loadcell}. + +Lastly, subjective metrics e.g., comfort, usability, user experience, fatigue +and satisfaction, are evaluated based on survey data collected after +participants used different input methods \cite{kim_typingforces, + bell_pauseboard, bufton_typingforces, pereira_typing_test, iso9241-411}. In +their study, Kim et al. used a survey provided by the \gls{ISO} which is +specifically designed to evaluate different keyboards in terms of user +satisfaction, comfort and usability \cite{kim_typingforces, iso9241-411}. This +survey poses a total of twelve questions concerning e.g., fatigue of specific +regions of the upper extremity, general satisfaction with the keyboard, +perceived precision and uniformity while typing, etc., which are presented on a +seven-point Likert-scale \cite{iso9241-411}. Further, studies concerning the +usability and user experience of different text entry methods used the \gls{UEQ} +or \gls{UEQ-S} to evaluate the differences in those categories \cite{nguyen_ueq, + olshevsky_ueq, gkoumas_ueq}. While the full \gls{UEQ} provides a total of 26 +questions divided into six scales (attractiveness, perspicuity, efficiency, +dependability, stimulation and novelty), the \gls{UEQ-S} only features 8 +questions and two scales (pragmatic and hedonic quality). Because of the limited +explanatory power of the \gls{UEQ-S}, it is recommended to only use it, if there +is not enough time to complete the full \gls{UEQ} or if the participants of a +study are required to rate several products in one session +\cite{schrepp_ueq_handbook}. + +\subsubsection{Relevance for this thesis} +Measuring metrics related to data entry tasks can be performed with the help +several commercially available tools and equipment. Especially muscle activity +has to be measured with appropriate tools and accurate placement of the +electrodes is important to ensure quality results \cite{takala_emg, halaki_emg, + kim_typingforces, gerard_keyswitch}. Metrics related to performance such as +\gls{WPM}, \gls{CER} and \gls{UER} are well defined and can be applied in almost +any experimental setup concerning the transcription of text +\cite{soukoreff_metrics, mackenzie_metrics}. In addition to the measured data, +questionnaires can help to gather subjective feedback about the keyboards and +thereby reveal differences that cannot be easily acquired by a device or formula +\cite{rowley_surveys}. + -\subsection{Satisfaction while using a keyboard} -\subsection{Text understandability / FRE} \subsection{Crowdsourcing / Observer Bias} -\subsection{Keyboard usage} -\subsection{Keyswitch types} -- Rubber dome -- Mechanical switches (Why linear -> rubberdome is not tactile nor has audible feedback) -\subsection{Muscle activity / EMG measurements} -\subsection{Finger strength} -\subsection{Traditional methods} -\subsection{Alternative methodology} -- Available Methods (Impact vs load) -- Load cells \ No newline at end of file +As shown by the previous research in Section \ref{sec:metrics}, it is common +practice in research related to typing to present a text that has to be +transcribed by the participant. Usually, the text was chosen by the researcher +or already available through the used typing test software. If the +understandability of text is of concern, the binary choice of, is understandable +or not, made by the researcher could lead to a phenomenon called the observer +bias \cite{hrob_observer, berger_observer}. Thus, the text could potentially be +to difficult to understand for the participants if not evaluated with e.g. the +\gls{FRE} or other adequate formulas. Further, if there is previous knowledge +about the requested participants, the researcher could subconsciously select +text that is familiar to, or well received by some of the subjects and could +thereby conceivably influence the outcome \cite{hrob_observer, berger_observer}. +The same problem arises, if the typing test software already provides such texts +but the researcher has to select some of them for the experiment. Further, the +difficulty of the provided texts should be verified to ensure accurate results +across multiple treatments. A possible solution for this problem is +crowdsourcing. + +Howe CONTINUE + + +\cite{howe_crowdsource}. If there are automated checks for text +difficulty in place, this method completely excludes the researcher from the +text selection process. + + +\subsubsection{Relevance for this thesis} + +% \subsection{Keyboard usage} +% \subsection{Finger strength} +% \subsection{Traditional methods} +% \subsection{Alternative methodology} +% - Available Methods (Impact vs load) +% - Load cells \ No newline at end of file diff --git a/chap3/implementation.tex b/chap3/implementation.tex index 3e61c69..135e88d 100644 --- a/chap3/implementation.tex +++ b/chap3/implementation.tex @@ -1,5 +1,6 @@ -\section{Typing Test} +\section{Implementation} \label{sec:label} - -\section{Finger strength measurement device} +\subsection{Typing Test Platform} +\label{sec:label} +\subsection{Finger strength measurement device} \label{sec:label} \ No newline at end of file diff --git a/chap4/methodology.tex b/chap4/methodology.tex index 5baef46..6d57711 100644 --- a/chap4/methodology.tex +++ b/chap4/methodology.tex @@ -1,5 +1,6 @@ -\section{Research Approach} -\section{Analysis of available mechanical keyswitches} -- Why have we chosen these switches -\section{Preliminary telephone interview} -\section{Preliminary study of finger strength} +\section{Methodology} +\subsection{Research Approach} +\subsection{Market analysis of available mechanical keyswitches} +\subsection{Preliminary telephone interview} +\subsection{Preliminary study of finger strength} +% armstrong measurments of finger strength diff --git a/chap5/results.tex b/chap5/results.tex index 872aa27..847d5ac 100644 --- a/chap5/results.tex +++ b/chap5/results.tex @@ -1 +1,5 @@ -results \ No newline at end of file +\section{Results} +A rapid method that creates many corrected errors, has efficient error correction, and leaves +few uncorrected errors can still be considered a successful method, since it produces +accurate text in relatively little time. pp. 56 MacKenzie +\label{sec:label} diff --git a/chap6/discussion.tex b/chap6/discussion.tex index 845add5..fc373b4 100644 --- a/chap6/discussion.tex +++ b/chap6/discussion.tex @@ -1 +1,2 @@ -Discussion \ No newline at end of file +\section{Discussion} +\label{sec:label} diff --git a/chap6/recommendations.tex b/chap6/recommendations.tex index e660443..fd75cf9 100644 --- a/chap6/recommendations.tex +++ b/chap6/recommendations.tex @@ -1 +1,2 @@ -Recommendations \ No newline at end of file +\section{Recommendations} +\label{sec:label} diff --git a/chap7/conclusion.tex b/chap7/conclusion.tex index 8b023b6..21f32a7 100644 --- a/chap7/conclusion.tex +++ b/chap7/conclusion.tex @@ -1 +1,2 @@ -Conclusion \ No newline at end of file +\section{Conclusion} +\label{sec:label} diff --git a/chap7/future_work.tex b/chap7/future_work.tex index 99b658f..df3d859 100644 --- a/chap7/future_work.tex +++ b/chap7/future_work.tex @@ -1 +1,2 @@ -Future work \ No newline at end of file +\section{Future work} +\label{sec:label} diff --git a/chap7/limitations.tex b/chap7/limitations.tex index 66332a0..4aa3dcf 100644 --- a/chap7/limitations.tex +++ b/chap7/limitations.tex @@ -1 +1,2 @@ -limitlimitss \ No newline at end of file +\section{Limitations} +\label{sec:label} diff --git a/glossary.tex b/glossary.tex index a1c7ada..7a3d6a1 100644 --- a/glossary.tex +++ b/glossary.tex @@ -1,11 +1,12 @@ %----------Glossar/Glossary------------------------------------------------------------- \newacronym{KB}{KB}{Keyboard} -\newacronym{EMG}{EMG}{Electromyography} +\newacronym{EMG}{EMG}{electromyography} +\newacronym{MVC}{MVC}{maximum voluntary contraction} \newacronym{CTS}{CTS}{Carpal Tunnel Syndrome} \newacronym{RSI}{RSI}{Repetitive Strain Injury} \newacronym{FRE}{FRE}{Flesch Reading Ease Score} -\newacronym{VAS}{VAS}{Visual Analog Scale} +\newacronym{VAS}{VAS}{visual analog scale} % Mulcles alive p. 189 % Atlas of Human Anatomy p. 433 \newacronym{FDS}{FDS}{flexor digitorum superficialis} @@ -15,6 +16,16 @@ \newacronym{ABS}{ABS}{acrylonitrile butadiene styrene} \newacronym{WRUED}{WRUED}{work related upper extremity disorders} \newacronym{PCB}{PCB}{printed circuit board} +\newacronym{WPM}{WPM}{Words per Minute} +\newacronym{AdjWPM}{AdjWPM}{Adjusted Words per Minute} +\newacronym{KSPS}{KSPS}{Keystrokes per Second} +\newacronym{CER}{CER}{Corrected Error Rate} +\newacronym{UER}{UER}{Uncorrected Error Rate} +\newacronym{KSPC}{KSPC}{Keystrokes per Character} +\newacronym{UEQ-S}{UEQ-S}{short version of the user experience questionnaire} +\newacronym{UEQ}{UEQ}{user experience questionnaire} + + \newglossaryentry{cN}{ @@ -29,6 +40,10 @@ description={Gram: 1 g $ \approx $ 0.97 cN} name={gf}, description={Gram-force: 1 gf = 1 g} } +\newglossaryentry{QWERTY}{ +name={QWERTY}, +description={Keyboard layout commonly used in the US and many other countries} +} \newglossaryentry{QWERTZ}{ name={QWERTZ}, description={Keyboard layout commonly used in Germany} @@ -41,5 +56,5 @@ description={Describes the scenario when the typist does not release the key bef \newglossaryentry{Topre}{ name={Topre}, -description={Topre switches are keyswitches produced by the Japanese company Topre Corporation +description={Topre switches are keyswitches produced by the Japanese company Topre Corporation} } diff --git a/images/keyboard_layouts.png b/images/keyboard_layouts.png new file mode 100644 index 0000000..9633af5 Binary files /dev/null and b/images/keyboard_layouts.png differ diff --git a/images/keyboard_models.jpg b/images/keyboard_models.jpg new file mode 100644 index 0000000..00d110b Binary files /dev/null and b/images/keyboard_models.jpg differ diff --git a/images/ks_fd_curves.jpg b/images/ks_fd_curves.jpg new file mode 100644 index 0000000..0ab71bc Binary files /dev/null and b/images/ks_fd_curves.jpg differ diff --git a/images/ks_fd_curves.jpg~ b/images/ks_fd_curves.jpg~ new file mode 100644 index 0000000..0d0f102 Binary files /dev/null and b/images/ks_fd_curves.jpg~ differ diff --git a/images/mech_keyswitches_dissas.jpg b/images/mech_keyswitches_dissas.jpg new file mode 100644 index 0000000..52151e4 Binary files /dev/null and b/images/mech_keyswitches_dissas.jpg differ diff --git a/images/mech_keyswitches_dissas.jpg~ b/images/mech_keyswitches_dissas.jpg~ new file mode 100644 index 0000000..35129c3 Binary files /dev/null and b/images/mech_keyswitches_dissas.jpg~ differ diff --git a/ref_shelf.bib b/ref_shelf.bib index 4f6d8b2..adc2c95 100644 --- a/ref_shelf.bib +++ b/ref_shelf.bib @@ -67,8 +67,6 @@ url = {https://www.realforce.co.jp/en/products/}, urldate = {2021-07-01} } - - @article{kim_typingforces, title = {Differences in typing forces, muscle activity, comfort, and typing performance among virtual, notebook, and desktop @@ -347,58 +345,66 @@ urldate = {2021-06-28} } @article{peery_3d_keyswitch, -title = {3D Printed Composite Keyboard Switches}, -journal = {Procedia Manufacturing}, -volume = {17}, -pages = {357-362}, -year = {2018}, -note = {28th International Conference on Flexible Automation and Intelligent Manufacturing (FAIM2018), June 11-14, 2018, Columbus, OH, USAGlobal Integration of Intelligent Manufacturing and Smart Industry for Good of Humanity}, -issn = {2351-9789}, -doi = {https://doi.org/10.1016/j.promfg.2018.10.057}, -url = {https://www.sciencedirect.com/science/article/pii/S2351978918311739}, -author = {Alec Peery and Dušan Sormaz}, -keywords = {Keyboard, Ergonomics, 3D Printing}, + title = {3D Printed Composite Keyboard Switches}, + journal = {Procedia Manufacturing}, + volume = 17, + pages = {357-362}, + year = 2018, + note = {28th International Conference on Flexible Automation and + Intelligent Manufacturing (FAIM2018), June 11-14, 2018, + Columbus, OH, USAGlobal Integration of Intelligent + Manufacturing and Smart Industry for Good of Humanity}, + issn = {2351-9789}, + doi = {https://doi.org/10.1016/j.promfg.2018.10.057}, + url = + {https://www.sciencedirect.com/science/article/pii/S2351978918311739}, + author = {Alec Peery and Dušan Sormaz}, + keywords = 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Martin, Bernard J and Rempel, David M}, - journal={American Industrial Hygiene Association Journal}, - volume={60}, - number={6}, - pages={762--769}, - year={1999}, - publisher={Taylor \& Francis} + title = {The effects of keyswitch stiffness on typing force, finger + electromyography, and subjective discomfort}, + author = {Gerard, Michael J and Armstrong, Thomas J and Franzblau, + Alfred and Martin, Bernard J and Rempel, David M}, + journal = {American Industrial Hygiene Association Journal}, + volume = 60, + number = 6, + pages = {762--769}, + year = 1999, + publisher = {Taylor \& Francis} } @online{te_connect, @@ -416,53 +422,298 @@ urldate = {2021-07-01} } @article{fagarasanu_force_training, - title={The training effect on typing on two alternative keyboards}, - author={Fagarasanu, Mircea and Kumar, Shrawan and Narayan, Yogesh}, - journal={International Journal of Industrial Ergonomics}, - volume={35}, - number={6}, - pages={509--516}, - year={2005}, - publisher={Elsevier} + title 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keyboard key spacing on typing speed, error, + usability, and biomechanics: Part 1}, + author = {Pereira, Anna and Lee, David L and Sadeeshkumar, Harini and + Laroche, Charles and Odell, Dan and Rempel, David}, + journal = {Human factors}, + volume = 55, + number = 3, + pages = {557--566}, + year = 2013, + publisher = {Sage Publications Sage CA: Los Angeles, CA} +} + +@online{cherry_mx_brown, +author = {Cherry AG}, +title = {CHERRY MX BROWN}, +url = {https://www.cherrymx.de/en/mx-original/mx-brown.html#techSpecs}, +urldate = {2021-07-01} +} + +@online{cherry_mx_blue, +author = {Cherry AG}, +title = {CHERRY MX BLUE}, +url = {https://www.cherrymx.de/en/mx-original/mx-blue.html#techSpecs}, +urldate = {2021-07-01} +} + +@online{cherry_mx_red, +author = {Cherry AG}, +title = {CHERRY MX RED}, +url = {https://www.cherrymx.de/en/mx-original/mx-red.html#techSpecs}, +urldate = {2021-07-01} +} + +@misc{wiki_kb_layouts, + author = "Wikimedia Commons contributors", + title = "File:Physical keyboard layouts comparison ANSI ISO JIS.png --- + Wikimedia Commons{,} the free media repository", + year = 2020, + url = + "\url{https://commons.wikimedia.org/w/index.php?title=File:Physical_keyboard_layouts_comparison_ANSI_ISO_JIS.png&oldid=504692555}", + urldate = {2021-07-02} +} + +@book{mackenzie_metrics, + title = {Text entry systems: Mobility, accessibility, universality}, + author = {MacKenzie, I Scott and Tanaka-Ishii, Kumiko}, + year = 2010, + publisher = {Elsevier} +} + +@inproceedings{soukoreff_metrics, + title = {Metrics for text entry research: An evaluation of MSD and + KSPC, and a new unified error metric}, + author = {Soukoreff, R William and MacKenzie, I Scott}, + booktitle = {Proceedings of the SIGCHI conference on Human factors in + computing systems}, + pages = {113--120}, + year = 2003 +} + +@article{gerard_audio_force, + title = {Short term and long term effects of enhanced auditory feedback + on typing force, EMG, and comfort while typing}, + author = {Gerard, Michael J and Armstrong, Thomas J and Rempel, David A + and Woolley, Chuck}, + journal = {Applied Ergonomics}, + volume = 33, + number = 2, + pages = {129--138}, + year = 2002, + publisher = {Elsevier} +} + +@article{martin_force, + title = {Keyboard reaction force and finger flexor electromyograms + during computer keyboard work}, + author = {Martin, Bernard J and Armstrong, Thomas J and Foulke, James A + and Natarajan, Sivakumaran and Klinenberg, Edward and Serina, + Elaine and Rempel, David}, + journal = {Human Factors}, + volume = 38, + number = 4, + pages = {654--664}, + year = 1996, + publisher = {SAGE Publications Sage CA: Los Angeles, CA} +} + +@article{rose_force, + title = {Keyboard operating posture and actuation force: Implications + for muscle over-use}, + author = {Rose, MJ}, + journal = {Applied Ergonomics}, + volume = 22, + number = 3, + pages = {198--203}, + year = 1991, + publisher = {Elsevier} +} + +@article{reaz_emg, + title = {Techniques of EMG signal analysis: detection, processing, + classification and applications}, + author = {Reaz, Mamun Bin Ibne and Hussain, M Sazzad and Mohd-Yasin, + Faisal}, + journal = {Biological procedures online}, + volume = 8, + number = 1, + pages = {11--35}, + year = 2006, + publisher = {Springer} +} + +@article{halaki_emg, + title = {Normalization of EMG signals: to normalize or not to normalize + and what to normalize to}, + author = {Halaki, Mark and Ginn, Karen}, + journal = {Computational intelligence in electromyography analysis-a + perspective on current applications and future challenges}, + pages = {175--194}, + year = 2012, + publisher = {InTech Rijeka} +} + +@article{takala_emg, + title = {Placement of forearm surface EMG electrodes in the assessment + of hand loading in manual tasks}, + author = {Takala, Esa-Pekka and Toivonen, Risto}, + journal = {Ergonomics}, + volume = 56, + number = 7, + pages = {1159--1166}, + year = 2013, + publisher = {Taylor \& Francis} +} + +@inproceedings{bell_pauseboard, + title = {PauseBoard: A Force-Feedback Keyboard for Unintrusively + Encouraging Regular Typing Breaks}, + author = {Bell, Lewis and Lees, Jay and Smith, Will and Harding, Charlie + and Lee, Ben and Bennett, Daniel}, + booktitle = {Extended Abstracts of the 2020 CHI Conference on Human Factors + in Computing Systems}, + pages = {1--8}, + year = 2020 +} + +@article{bufton_typingforces, + title = {Effect of keyswitch design of desktop and notebook keyboards + related to key stiffness and typing force}, + author = {Bufton, Marcia J and Marklin, Richard W and Nagurka, Mark L + and Simoneau, Guy G}, + journal = {Ergonomics}, + volume = 49, + number = 10, + pages = {996--1012}, + year = 2006, + publisher = {Taylor \& Francis} +} + +@misc{johnson_loadcell, + title = {Load cell}, + author = {Johnson, Thomas H}, + year = 1994, + publisher = {Google Patents}, + note = {US Patent 5,313,023} +} +@inproceedings{nguyen_ueq, + title={Text Input Methods in Virtual Reality using Radial Layouts}, + author={Nguyen, Anh and Bittman, Samuel and Zank, Markus}, + booktitle={26th ACM Symposium on Virtual Reality Software and Technology}, + pages={1--3}, + year={2020} +} + +@inproceedings{olshevsky_ueq, + title={Touchless Gestures for Interactive Messaging: Gesture Interface for Sending Emoji}, + author={Olshevsky, Vyacheslav and Bondarets, Ivan and Kozyr, Andrii and Trunov, Oleksandr and Shcherbina, Artem and Tolmachov, Igor and Alkhimova, Svitlana}, + booktitle={22nd International Conference on Human-Computer Interaction with Mobile Devices and Services}, + pages={1--4}, + year={2020} +} + +@inproceedings{gkoumas_ueq, + title={Usability of visibly adaptive smartphone keyboard layouts}, + author={Gkoumas, Apostolos and Komninos, Andreas and Garofalakis, John}, + booktitle={Proceedings of the 20th Pan-Hellenic Conference on Informatics}, + pages={1--6}, + year={2016} +} + +@article{schrepp_ueq_handbook, + title={User experience questionnaire handbook}, + author={Schrepp, Martin}, + journal={All you need to know to apply the UEQ successfully in your project}, + year={2015} +} + +@article{rowley_surveys, + title={Designing and using research questionnaires}, + author={Rowley, Jenny}, + journal={Management research review}, + year={2014}, + publisher={Emerald Group Publishing Limited} +} + +@article{hrob_observer, + title={Observer bias in randomised clinical trials with binary outcomes: systematic review of trials with both blinded and non-blinded outcome assessors}, + author={Hr{\'o}bjartsson, Asbj{\o}rn and Thomsen, Ann Sofia Skou and Emanuelsson, Frida and Tendal, Britta and Hilden, J{\o}rgen and Boutron, Isabelle and Ravaud, Philippe and Brorson, Stig}, + journal={Bmj}, + volume={344}, + year={2012}, + publisher={British Medical Journal Publishing Group} +} + +@article{berger_observer, + title={Wildbook: Crowdsourcing, computer vision, and data science for conservation}, + author={Berger-Wolf, Tanya Y and Rubenstein, Daniel I and Stewart, Charles V and Holmberg, Jason A and Parham, Jason and Menon, Sreejith and Crall, Jonathan and Van Oast, Jon and Kiciman, Emre and Joppa, Lucas}, + journal={arXiv preprint arXiv:1710.08880}, + year={2017} +} + +@article{schenk_crowdsource, +author = {Schenk, Eric and Guittard, Claude}, +year = {2009}, +month = {01}, +pages = {}, +title = {Crowdsourcing: What can be Outsourced to the Crowd, and Why ?} +} + +@article{howe_crowdsource, + title={The rise of crowdsourcing}, + author={Howe, Jeff and others}, + journal={Wired magazine}, + volume={14}, + number={6}, + pages={1--4}, + year={2006} } \ No newline at end of file diff --git a/thesis.tex b/thesis.tex index 077c01a..435c941 100644 --- a/thesis.tex +++ b/thesis.tex @@ -188,8 +188,8 @@ \cleardoublepage %Anhänge/Appendices - \include{appendices} - \cleardoublepage + % \include{appendices} + % \cleardoublepage %------------------------------------------------------------------------------------ %----------------DOKUMENTENENDE - END OF 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