From 5db67d2cc116aeb8a744ac8b60a026e4b2823439 Mon Sep 17 00:00:00 2001 From: phga Date: Sun, 4 Jul 2021 22:55:03 +0200 Subject: [PATCH] Update --- chap2/literature_review.tex | 256 +++++++++++++++++++++++------------- glossary.tex | 4 + ref_shelf.bib | 60 +++++++++ thesis.tex | 2 + titlepage.tex | 2 +- 5 files changed, 230 insertions(+), 94 deletions(-) diff --git a/chap2/literature_review.tex b/chap2/literature_review.tex index 360ef4e..ac3a9e9 100644 --- a/chap2/literature_review.tex +++ b/chap2/literature_review.tex @@ -2,7 +2,9 @@ % 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 .... -\subsection{Keyboards and key switches} +\subsection{Keyboards and Keyswitches} +\subsubsection{Keyboard Models and Layouts} +\label{sec:kb_layout} \begin{figure}[ht] \centering @@ -15,12 +17,12 @@ 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 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 primarily differ in -feel, durability, cost and sound \parencite[8]{bassett_keycap}. +appearance. The keyboards feature different enclosures and keycaps, which are +the rectangular pieces of plastic on top of the actual keyswitches that +sometimes indicate what 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 primarily differ in feel, durability, +cost and sound \parencite[8]{bassett_keycap}. \begin{figure}[ht] \centering @@ -31,16 +33,16 @@ feel, durability, cost and sound \parencite[8]{bassett_keycap}. \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 +Nowadays, there are three main standards that define the physical layout of a +keyboard―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}. These +layouts propose slightly different arrangements of the keys and some even alter +the shape of a few keys entirely. Figure \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 @@ -48,28 +50,36 @@ 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 +\cite{baker_ergo, rempel_ergo}. + +\subsubsection{Membrane Keyswitch} +\label{sec:mem_switch} + +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}. + +\subsubsection{Mechanical Keyswitch} +\label{sec:mech_switch} +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 @@ -154,7 +164,7 @@ typing speed, which could be more significant with greater variation of actuation force across tested keyboards \cite{loricchio_force_speed}. -\subsubsection{Relevance for this thesis} +\subsubsection{Relevance for this Thesis} Since this thesis is focused around keyboards and especially the relation between the actuation force of the keyswitch and efficiency (speed, error rate) and also the differences in satisfaction while using keyswitches with varying @@ -186,7 +196,7 @@ 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 typing related metrics} +\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 @@ -195,7 +205,12 @@ 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 + pereira_typing_test}. + +\subsubsection{Readability of Text} +\label{sec:meas_fre} + +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, @@ -232,6 +247,9 @@ classified according to the ranges given in Table \ref{tbl:fre_ranges} \cite{fle \end{tabular} \end{table} +\subsubsection{Performance Metrics} +\label{sec:meas_perf} + There are several metrics to measure the performance of typists. Typical methods to measure speed are \begin{enumerate} @@ -280,6 +298,9 @@ following two methods \end{equation} \end{enumerate} +\subsubsection{Electromyography} +\label{sec:meas_emg} + 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, @@ -312,29 +333,31 @@ 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}. +\subsubsection{Subjective Metrics} +\label{sec:meas_sub} 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} +their study, Kim et al. used a modified version of the \gls{KCQ} 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 @@ -348,38 +371,85 @@ thereby reveal differences that cannot be easily acquired by a device or formula \cite{rowley_surveys}. -\subsection{Crowdsourcing / Observer Bias} -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 +\subsection{Observer Bias and a Possible Solution} +As already discussed 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, angrosino_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 +thereby conceivably influence the outcome of the study\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. Furthermore, the difficulty of the provided texts should be verified +to ensure accurate results across multiple treatments. A possible solution to +this problem is crowdsourcing. Howe describes crowdsourcing as the act of +outsourcing a problem to a group of individuals that are voluntarily working +together to solve it \parencite[1-11]{howe_crowd_book} \& +\cite{howe_crowdsource, schenk_crowdsource}. + +Observer bias can also occur while conducting the experiment when the researcher +has to give instructions to the subject. Therefore, it is important to treat +every participant equally by following a predefined procedure and minimize +unnecessary interaction where possible to further minimize the risk of bias +\parencite[674]{angrosino_observer}. + + +\subsubsection{Relevance for this Thesis} +Summarizing, even seemingly arbitrary decisions or actions can have a potential +undesirable impact on the results of a study. If it is possible to implement +automated checks for the suitability of text e.g., a platform that verifies +submitted text based on \gls{FRE} scores, crowdsourcing could be used to +completely exclude the researcher from the text selection process and therefore +mitigate the risk of unwanted bias. In addition, the aspect of time in the +preparation phase of a study could be another factor to consider crowdsourcing +to acquire larger amounts of text with equal difficulty. + +\subsection{Strength of Individual Fingers} +As already mentioned in Section \ref{sec:metrics}, the force applied to a +keyswitch is the concern of multiple studies that evaluate the relation between +keyboarding and \gls{WRUED}. Further, multiple studies came to the conclusion, +that there is a significant discrepancy in strength between individual fingers +\cite{bretz_finger, martin_force, baker_kinematics, dickson_finger}. Bretz et +al. found, that when participants squeezed an object between thumb and finger, +differences in applicable force between different fingers ranged from 1.6 +\gls{N} up to 25.9 \gls{N} (n=16) \cite{bretz_finger}. Dickson and Nicolle +observed the effects of surgery on patients with rheumatoid hands. The pre and +post surgery force of finger flexion was recorded and the post surgery results +yielded a difference in flexion force, which is similar to the force required to +actuate a keyswitch, that ranged from 1 \gls{N} to 4 \gls{N} +\cite{dickson_finger}. Martin et al. measured applied average and peak force of +individual digits while typing on a keyboard (n=10). The measured differences +ranged from 0.10 \gls{N} to 1.49 \gls{N} for peak force and 0.01 \gls{N} to 0.08 +\gls{N} for mean force \cite{martin_force}. + +\subsubsection{Relevance for this Thesis} +The goal of this thesis is to evaluate the possible advantages of keyboards with +non-uniform actuation forces. The fairly small difference of only 0.08 \gls{N} in mean +force applied to keyboards recorded by Martin et al. \cite{martin_force} but +rather big difference in finger strength measured by Bretz et +al. \cite{bretz_finger} could indicate, that albeit the difference in strength, +all fingers have to apply equal force to generate a keypress because of the +uniform actuation force used in commercially available keyboards. + +\subsection{Summary} +Since keyboards are still the most commonly used input method for data entry to +date and so far all efforts to convince the mainstream to move from the +standard, less ergonomic, physical layouts to split keyboards failed, further +alternatives that could be easily implemented into manufacturing processes have +to be explored, to counteract the rising risks for \gls{WRUED}. One factor +related to \gls{WRUED} is the actuation force of the keyswitches +\cite{bufton_typingforces, rempel_ergo, rempel_force, + gerard_keyswitch}. Especially higher actuation forces have shown to be the +reason for discomfort in the upper extremity. On the other hand, higher +actuation forces also led to lower error rates while typing and therefore +enhance user satisfaction and performance \cite{gerard_keyswitch}. With the help +of several methods to measure typing relate metrics such as muscle activity +(\gls{EMG}), error rates (\gls{CER} and \gls{UER}), typing speed (\gls{WPM}) and +user satisfaction {\gls{UEQ} and \gls{KCQ}} it is feasible to evaluate possible +alternative input methods to the more traditional keyboard. diff --git a/glossary.tex b/glossary.tex index 7a3d6a1..cad0a3b 100644 --- a/glossary.tex +++ b/glossary.tex @@ -27,6 +27,10 @@ +\newglossaryentry{N}{ +name={N}, +description={Newton: 1 N $ \approx $ 101.97 g} +} \newglossaryentry{cN}{ name={cN}, diff --git a/ref_shelf.bib b/ref_shelf.bib index adc2c95..0a2e384 100644 --- a/ref_shelf.bib +++ b/ref_shelf.bib @@ -344,6 +344,17 @@ urldate = {2021-06-28} publisher = {Elsevier} } +@article{rempel_force, + title={The effect of keyboard keyswitch make force on applied force and finger flexor muscle activity}, + author={Rempel, David and Serina, Elaine and Klinenberg, Edward and Martin, Bernard J and Armstrong, Thomas J and Foulke, James A and Natarajan, Sivakumaran}, + journal={Ergonomics}, + volume={40}, + number={8}, + pages={800--808}, + year={1997}, + publisher={Taylor \& Francis} +} + @article{peery_3d_keyswitch, title = {3D Printed Composite Keyboard Switches}, journal = {Procedia Manufacturing}, @@ -716,4 +727,53 @@ title = {Crowdsourcing: What can be Outsourced to the Crowd, and Why ?} number={6}, pages={1--4}, year={2006} +} + +@book{howe_crowd_book, + title = {Crowdsourcing: How the Power of the Crowd is Driving the Future of Business}, + author = {Jeff Howe}, + publisher = {Random House Business}, + isbn = {1905211155, 9781905211159}, + year = {2006}, +} + +@article{angrosino_observer, + title={Rethinking observation: From method to context}, + author={Angrosino, Michael V and Mays de P{\'e}rez, Kimberly A}, + journal={Handbook of qualitative research}, + volume={2}, + pages={673--702}, + year={2000} +} + +@article{bretz_finger, + title={Force measurement of hand and fingers}, + author={K{\'a}roly J{\'a}nos, Bretz and {\'A}kos, Jobb{\'a}gy and K{\'a}roly, Bretz}, + journal={Biomechanica Hungarica}, + volume={3}, + number={1}, + year={2010} +} + + +@article{baker_kinematics, + title={Kinematics of the fingers and hands during computer keyboard use}, + author={Baker, Nancy A and Cham, Raki{\'e} and Cidboy, Erin Hale and Cook, James and Redfern, Mark S}, + journal={Clinical Biomechanics}, + volume={22}, + number={1}, + pages={34--43}, + year={2007}, + publisher={Elsevier} +} + +@article{dickson_finger, + title={The assessment of hand function: Part 1—Measurement of Individual Digits}, + author={Dickson, RA and Nicolle, FV}, + journal={The Hand}, + volume={4}, + number={3}, + pages={207--214}, + year={1972}, + publisher={Elsevier} } \ No newline at end of file diff --git a/thesis.tex b/thesis.tex index 435c941..51b6fc7 100644 --- a/thesis.tex +++ b/thesis.tex @@ -18,6 +18,8 @@ \usepackage[UKenglish]{babel} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} +\usepackage{kpfonts} +% \usepackage{mathpazo} % verbesserter Randausgleich \usepackage{microtype} diff --git a/titlepage.tex b/titlepage.tex index d268418..044fd9a 100644 --- a/titlepage.tex +++ b/titlepage.tex @@ -25,7 +25,7 @@ Faculty of Computer Science\\ [7em] \Large\textbf{ - Impact of adjusted, per key, actuation force on efficiency and satisfaction while using mechanical keyboards} \\ + Impact of Adjusted, per Key, Actuation Force on Efficiency and Satisfaction While Using Mechanical Keyboards} \\ \end{center} \vfill