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chap3/implementation.tex
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@ -264,7 +264,7 @@ func calculateFRE(txt string) float64 {
\end{listing}
\end{enumerate}
\subsection{Finger strength measurement device}
\subsection{Finger Strength Measurement Device}
\label{sec:force_meas_dev}
\begin{figure}[ht]

187
chap4/methodology.tex
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@ -23,7 +23,7 @@ performance and user satisfaction while using four different keyboards,
including our adjusted keyboard, to values obtained with the participant's own
keyboards.
\subsection{Preliminary telephone interview}
\subsection{Preliminary Telephone Interview}
\label{sec:telephone_interview}
Some of the studies we found that researched implications of actuation force on
speed, preference or other metrics were published between 1984 and 2010. That is
@ -63,7 +63,7 @@ Web\footnote{\url{https://web.whatsapp.com/}}, Signal
Desktop\footnote{\url{https://signal.org/download/}}, Telegram
Desktop\footnote{\url{https://desktop.telegram.org/}}).
\subsection{Market analysis of available mechanical keyswitches}
\subsection{Market Analysis of Available Mechanical Keyswitches}
\label{sec:market_forces}
To gather information about available actuation forces, we collected the product
lines of keyswitches for all well known manufacturers, namely
@ -90,7 +90,7 @@ actuation force is 35 g ($\approx$ 0.34 \gls{N}) the most common one is 50 g
\label{fig:keyswitches_brands}
\end{figure}
\subsection{Preliminary study of finger strength}
\subsection{Preliminary Study of Finger Strength}
To evaluate the impact of an adjusted keyboard (keyboard with non-uniform
actuation forces) on performance and satisfaction we first needed to get an
understanding on how to distribute keyswitches with different actuation forces
@ -255,7 +255,7 @@ which is discussed in more detail in the following section.
\label{fig:adjusted_layout}
\end{figure}
\subsection{Main user study}
\subsection{Main User Study}
\label{sec:main_study_meth}
\subsubsection{Hypotheses}
\label{sec:main_hypotheses}
@ -352,13 +352,14 @@ researchers were tested with antigen tests prior to every appointment.
\label{sec:main_keyboards}
Additionally to the reference tests conducted with the participant's own
keyboards, we provided four keyboards which only differed in terms of actuation
force. We decided to assign pseudonyms in the form of Greek goddesses to the
keyboards to make fast differentiation during the sessions easier and reduce
ambiguity. The pseudonyms for each keyboard and the corresponding actuation
force can be found in Table \ref{tbl:kb_pseudo}. All keyboards used the standard
ISO/IEC 9995 \cite{iso9995-2} physical layout and provided keycaps representing
the German \gls{QWERTZ} layout, which all participants were already familiar
with. All four keyboards used in the experiment were
force (Appendix \ref{app:equipment}). We decided to assign pseudonyms in the form
of Greek goddesses to the keyboards to make fast differentiation during the
sessions easier and reduce ambiguity. The pseudonyms for each keyboard and the
corresponding actuation force can be found in Table \ref{tbl:kb_pseudo}. All
keyboards used the standard ISO/IEC 9995 \cite{iso9995-2} physical layout and
provided keycaps representing the German \gls{QWERTZ} layout, which all
participants were already familiar with. All four keyboards used in the
experiment were
\textit{\gls{GMMK}}\footnote{\url{https://www.pcgamingrace.com/products/gmmk-full-brown-switch}}
equipped with \textit{Gateron} mechanical
keyswitches\footnote{\url{http://www.gateron.com/col/58459?lang=en}}. The order
@ -411,10 +412,10 @@ information about privacy, the \gls{EMG} measurements and questionnaires used
during the experiment. Next, participants filled out a pre-experiment
questionnaire to gather demographic and other relevant information e.g., touch
typist, average \gls{KB} usage per day, predominantly used keyboard type,
previous medical conditions affecting the result of the study e.g., \glsfirst{RSI},
\glsfirst{CTS}, etc. The full questionnaire can be observed in the appendix
\ref{app:gott}. Further, participants could adjust the chair, table and monitor
to a comfortable position.
previous medical conditions affecting the result of the study e.g.,
\glsfirst{RSI}, \glsfirst{CTS}, etc. The full questionnaire can be observed in
Appendix \ref{app:gott}. Further, participants could adjust the chair, table and
monitor to a comfortable position.
\textbf{\gls{EMG} Measurements}
@ -443,13 +444,13 @@ and 0\%\gls{MVC}), which are used later to calculate the percentage of muscle
activity for each test, we performed three measurements. First, participants
were instructed to fully relax the \gls{FDS}, \gls{FDP} and \gls{ED} by
completely resting their forearms on the table. Second, participants exerted
maximum possible force with their fingers against the top of the table
maximum possible force with their fingers (volar) against the top of the table
(\gls{MVC} - flexion) and lastly, participants applied maximum possible force
with their fingers to the bottom of the table while resting their forearms on
their thighs (\gls{MVC} - extension). We decided to also measure 0\%\gls{MVC}
before and after each typing test and used these values to normalize the final
data instead of the 0\%\gls{MVC} we retrieved from the initial \gls{MVC}
measurements.
with their fingers (dorsal) to the bottom of the table while resting their
forearms on their thighs (\gls{MVC} - extension). We decided to also measure
0\%\gls{MVC} before and after each typing test and used these values to
normalize the final data instead of the 0\%\gls{MVC} we retrieved from the
initial \gls{MVC} measurements.
\textbf{Familiarization with \glsfirst{GoTT} and the Keyboards}
@ -479,78 +480,72 @@ almost identical \gls{FRE} scores (mean = 80.10, SD = 0.48).
To receive feedback about several aspects that define a satisfactory user
experience while using a keyboard, we decided to incorporate two questionnaires
into our experiment. The first questionnaire was the \glsfirst{KCQ} provided by
\cite[56]{iso9241-411} and was filled out after each individual typing test. The
second survey, that was filled out every time the keyboard was changed, was the
\glsfirst{UEQ-S} \cite{schrepp_ueq_handbook} with an additional question―``How
satisfied have you been with this keyboard?''―that could be answered with the
help of an \gls{VAS} ranging from 0 to 100 \cite{lewis_vas}. The short version
of the \gls{UEQ} was selected, because of the limited time participants had to
fill out the questionnaires in between typing tests (2 - 3 minutes) and also
because participants had to rate multiple keyboards in one session
\cite{schrepp_ueq_handbook}.
\item Initial typing test with own keyboard. (5 min) \\
Adjusted follow-up ISO keyboard comfort questionnaire. (2 min) \\
Pause with light stretching exercises. (3 min)
\item \textbf{Main Part of the Experiment:} In this part the subject had
to take two, 5 minute, typing tests per keyboard, with a total of 4
keyboards (\textit{Nyx, Aphrodite, Athena, Hera}). After each typing
test, the subject had to fill out the post typing test survey
(\gls{KCQ}). Keyboards A, B and C are equipped with one set of
keyswitches and therefore each of the keyboards provides one of the
following, uniform, actuation forces across all keyswitches: 35 \gls{g},
50 \gls{g} or 80 \gls{g}. These specific values are the results of a
self conducted comparison between the product lines of most major
keyswitch manufacturers. The results shown in appendix
\ref{app:keyswitch} yield, that the lowest broadly available force for
keyswitches is 35 \gls{g}, the highest broadly available force is 80
\gls{g}, and the most common offered force is 50 \gls{g}. Keyboard D is
equipped with different zones of keyswitches that use appropriate
actuation forces according to finger strength differences and key
position. The keyboards used in this experiment are visually identical,
ISO/IEC 9995-1 conform \cite{iso9995-1} and provide a \gls{QWERTZ}
layout to resemble the subjects day-to-day layout and keyboard format as
close as possible. All keyboards are equipped with linear mechanical
keyswitches from one manufacturer to minimize differences in haptic and
sound while typing. To mitigate order effects, the order of the
keyboards is counterbalanced with the help of the latin square method
and the text snippets for the individual tests are randomized
\cite{statist_counterbalancing}. \textbf{(total: 80 min)}
\begin{enumerate}
\item \textbf{\gls{KB} A, Part 1:} Typing test. (5min) \\
Adjusted follow-up ISO keyboard comfort questionnaire. (2 min) \\
Pause with light stretching exercises. (3 min)
\item \textbf{\gls{KB} A, Part 2:} Typing test. (5min) \\
Adjusted follow-up ISO keyboard comfort questionnaire. (2 min) \\
Pause with light stretching exercises. (3 min)
\item \textbf{\gls{KB} C, Part 1:} Typing test. (5min) \\
Adjusted follow-up ISO keyboard comfort questionnaire. (2 min) \\
Pause with light stretching exercises. (3 min)
\item \textbf{\gls{KB} C, Part 2:} Typing test. (5min) \\
Adjusted follow-up ISO keyboard comfort questionnaire. (2 min) \\
Pause with light stretching exercises. (3 min)
\item \textbf{\gls{KB} B, Part 1:} Typing test. (5min) \\
Adjusted follow-up ISO keyboard comfort questionnaire. (2 min) \\
Pause with light stretching exercises. (3 min)
\item \textbf{\gls{KB} B, Part 2:} Typing test. (5min) \\
Adjusted follow-up ISO keyboard comfort questionnaire. (2 min) \\
Pause with light stretching exercises. (3 min)
\item \textbf{\gls{KB} D, Part 1:} Typing test. (5min) \\
Adjusted follow-up ISO keyboard comfort questionnaire. (2 min) \\
Pause with light stretching exercises. (3 min)
\item \textbf{\gls{KB} D, Part 2:} Typing test. (5min) \\
Adjusted follow-up ISO keyboard comfort questionnaire. (2 min) \\
Pause with light stretching exercises. (3 min)
\end{enumerate}
\item Post-Test semi-structured interview: The participant has to draw three
different UX curves \cite{kujala_ux_curve} to evaluate how fatigue,
performance and overall usability of the individual keyboards were perceived
during the experiment. While drawing the UX curve, participants should
describe their thought process. To reduce errors in the later evaluation of
the UX curves, the entire interview is recorded. (10 min)
\end{enumerate}
\cite[56]{iso9241-411} and was filled out after each individual typing test
(\glsfirst{PTTQ}). The second survey, that was filled out every time the keyboard
was changed, was the \glsfirst{UEQ-S} \cite{schrepp_ueq_handbook} with an
additional question―``How satisfied have you been with this keyboard?''―that
could be answered with the help of an \gls{VAS} ranging from 0 to 100
(\glsfirst{PKQ})\cite{lewis_vas}. The short version of the \gls{UEQ} was selected, because of
the limited time participants had to fill out the questionnaires in between
typing tests (2 - 3 minutes) and also because participants had to rate multiple
keyboards in one session \cite{schrepp_ueq_handbook}.
\textbf{Post Experiment Interview \& UX-Curves}
To give participants the chance to recapitulate their experience during the
whole experiment, we conducted a semi-structured interview, after all typing
tests were completed. We recorded audio and video for the whole duration of the
interviews and afterwards categorized common statements about each
keyboard.
Further, we prepared two different graphs were participants had to draw
UX-Curves related to subjectively perceived typing speed and subjectively
perceived fatigue for every keyboard and corresponding typing test. The graphs
always reflected the order of keyboards for the group the current participant
was part of. Furthermore, before the interview started, participants were given
a brief introduction on how to draw UX-Curves and that it is desirable to
explain the thought process while drawing each curve \cite{kujala_ux_curve}. An
example of the empty graph for perceived fatigue (group 1) can be seen in Figure
\ref{fig:empty_ux_g1}.
\begin{figure}[ht]
\centering
\includegraphics[width=1.0\textwidth]{images/empty_ux_g1}
\caption{Empty graph for participants of group 1 to draw an UX-curve related
to perceived fatigue during the experiment}
\label{fig:empty_ux_g1}
\end{figure}
\textbf{Main Part of the Experiment}
Each subject had to take two, 5 minute, typing tests per keyboard, with a total
of 5 keyboards, namely \textit{Own (participant's own keyboard)}, \textit{Nyx
(35 g, uniform), Aphrodite (50 g, uniform), Athena (80 g uniform)} and
\textit{Hera (35 g - 60 g, adjusted)} (Table \ref{tbl:kb_pseudo}). As described
in Section \ref{sec:main_keyboards}, the order of the keyboards \textit{Nyx,
Aphrodite, Athena} and \textit{Hera} was counterbalanced with the help of a
balanced latin square to reduce order effects. The keyboard \textit{Own} was
used to gather reference values for all measured metrics. Thus, typing tests
with \textit{Own} were conducted before (one test) and after (one test) all
other keyboards, to also capture possible variations in performance due to
fatigue. Participants were allowed, but not forced to, correct mistakes during
the typing tests. The typing test application allowed no shortcuts to delete or
insert multiple characters and correction was only possible by hitting the
\textit{Backspace} key on the keyboard. The \textit{Capslock} key was disable
during all typing tests, because there was only visual feedback in form of
coloring of correct and incorrect input and no direct representation of entered
characters (Figure \ref{fig:gott_colorblind}), which could lead to confusion
when the \textit{Capslock} key is activated on accident.
\subsection{Summary}
\label{sec:meth_summary}
The preliminary telephone interview and the market analysis of available
mechanical keyswitches allowed us to gather profound information concerning
user's preferences and availability of hardware components. Additionally, the
preliminary study, where we measured the maximum applicable force onto a
keyswitch for each finger of the right hand in different positions, yielded
necessary data for the design of the adjusted keyboard layout. Throughout the
main user study, where we compared five different keyboards, we were able to
obtain various qualitative and quantitative data regarding performance and
satisfaction. The statistical evaluation of this data will be presented in the
next Section.

13
chap5/results.tex
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@ -1,5 +1,10 @@
% 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
\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}
\label{sec:results}
This section addresses the statistical analysis of the data obtained throughout
the main, within-subject, user study (n = 24) that consisted of five repeated
measurements. Because the data was from related, dependent groups, we used
repeated measurement \gls{ANOVA} if all required assumption were met and
Friedman's Test otherwise.

2
glossary.tex
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@ -36,6 +36,8 @@
\newacronym{OLED}{OLED}{organic light-emitting diode}
\newacronym{GMMK}{GMMK}{Glorious Modular Mechanical Keyboards}
\newacronym{ANOVA}{ANOVA}{analysis of variance}
\newglossaryentry{N}{
name={N},
description={Newton: 1 N $ \approx $ 101.97 g}

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