% Chapter 0 - Proposal
% Section 1 - Motivation, problem statement and thesis objectives
\section{Bachelor Thesis Proposal - Philip Gaber}
{\huge Impact of adjusted, per key, actuation force on efficiency and satisfaction while using mechanical keyboards}
\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, dome/membrane switches,
often used in low- to mid-priced keyboards, and mechanical switches which are
the main switch type for high-priced 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
with adjusted actuation forces per finger or even customizable keyboards, where
an individual can select the actuation force for each keyswitch individually.

\subsection{Proposed Objective, Research Question and Hypothesis}

% This thesis is intended to provide an overview of already conducted research in
% the domain of keyboards, especially in connection with actuation force and the
% impact of different keyswitches on keyboard users.

% Because there is no previous research in the particular field of per finger/key
% actuation force for (mechanical) keyboards and the impact of such customization
% on efficiency and comfort, this thesis is also intended to research if this is a
% viable option in comparison to the classic keyboard with uniform actuation
% force. Therefore the author proposes to answer the question:

This thesis is intended to research if a keyboard with zones of keys, which have
adjusted actuation force depending on the assigned finger for that zone and the
position on the keyboard, is a viable option compared to the standard keyboard
with uniform actuation force across all keyswitches.

\begin{tabular}{p{0.3cm} p{0.5cm} p{13cm} p{0.5cm}}
  & \textbf{\large RQ}	& {\Large Does an adjusted actuation force per key have a positive impact on efficiency and overall satisfaction while using a mechanical keyboard?} & \\
\end{tabular}
\vspace{1em}

% TODO: Dissatisfied statt comfort da hohe error rate und dadurch frustriert
% TODO: Bei hypothesen noch error rate bei geschwindigkeit mit einbeziehen
% ASK: Doch noch comfort mit einbeziehen?
\begin{longtable}{p{0.3cm} p{0.5cm} p{13cm} p{0.5cm}}
  & \textbf{H1}	& Lower key actuation force improves typing speed over higher key actuation force (efficiency - speed). & \\
  & & & \\
  & \textbf{H2}	& Higher key actuation force decreases typing errors compared to lower key actuation force (efficiency - error rate). & \\
  & & & \\
  & \textbf{H3}	& Keys with lower actuation force are perceived as more satisfactory to write with than keys with higher actuation force. & \\
  & & & \\
  & \textbf{H4}	& Users perform better and feel more satisfied while using Keyboards with adjusted key actuation force than without the adjustment. & \\
\end{longtable}


\section{Proposed Method}

\subsection{Subjects}

Main target group to recruit participants for the research study from are
personal contacts and fellow students. It is planned to recruit ~20 participants
in total. Participants are required to type with more than just one finger per
hand. Thus, touch typing is not a mandatory but helpful skill to
participate. The age distribution for the subjects is estimated to be between 18
and 56 years. The average typing speed should be known prior to the main
experiment. Therefore, a typing speed test should be performed on the subject's
own keyboard beforehand. This pre experiment typing test has to be performed
within the standardized test environment consisting of an adjustable chair,
desk, monitor and the typing test software used within the main experiment.
Also, all subjects have to give their written consent to participate in the
study.

\subsection{Study design}

The experiment should consist of a experimental group and a control group. The
control group will perform all typing tests with the same keyboard. The text
used for the typing test should be easily understandable. Therefore, the text
has to be evaluated with the help of a Flesch-Kincaid scala \cite{flesch_fre}
adjusted for German language \cite{amstad_fre}.

\begin{equation}\label{fre_german}
  FRE_{deutsch} = 180 - \underbrace{ASL}_{\mathclap{\text{Average Sentence Length}}} - (58,5 * \overbrace{ASW}^{\mathclap{\text{Average Syllables per Word}}})
\end{equation}

The adjusted formula (\ref{fre_german}) to estimate the understandability of the
texts used in this experiment usually yields a number in the range of
\([0;100]\) called the \gls{FRE}. Higher \gls{FRE}s refer to better
understandability and thus the texts used in this experiment all have to fulfill
the requirement of a \gls{FRE} \(> 60\) which represents a standard text
\cite{amstad_fre} and \cite{flesch_fre}.

One typing test will consist of several smaller, randomly chosen, texts
snippets. The length of the snippets has to be between 100 and 400 characters
and a snippet has meet the \gls{FRE} requirement. The snippets are generated by
volunteers via the web interface of the platform used in this experiment which
can be seen in Figure \ref{gott:contribute_text}.

\begin{figure}[h!]
  \centering
  \includegraphics[width=0.42\textwidth]{images/gott_contribute_text.png}
  \caption{Go TyingTest (GoTT) - Text contribution section }
  \label{gott:contribute_text}
\end{figure}


% ASK: Should there be a control group at all, if so should they use their own keyboard or always the same random keyboard while they think they are testing different keyswitches?

\textbf{Planned experiment procedure:}

\begin{enumerate}
  \item Pre-Test questionnaire to gather demographic and other relevant
  information e.g., touch typist, average \gls{KB} usage per day and previous
  medical conditions affecting the result of the study \gls{RSI}, \gls{CTS},
  etc. (5 min)

  % ASK: Medical conditions OK?

  \item Adjustment of test environment (Chair height, monitor height, etc.) (2 min)
  \item Familiarization with the typing test (5 min)
  \item Familiarization with the keyboard (5 min)
  \item \textbf{Main-Test part 1 (H1-H3):} In this part the subject has to take
  two, 5 minute, typing tests per keyboard, with a total of 3 keyboards
  (\gls{KB} A, \gls{KB} B, \gls{KB} C). After each typing test, the subject has
  to fill out the post typing test keyboard comfort questionnaire. Each keyboard
  is equipped with one set of keyswitches and therefore provides one of the
  following, uniform, actuation forces across the whole keyboard: 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}. The keyboards used in this experiment are visually identical, ISO/IEC
  9995-1 conform \cite{iso9995-1} and provide a \gls{QWERTZ} layout to match the subjects
  day-to-day layout and keyboard format. All keyboards are equipped with linear
  mechanical keyswitches from one manufacturer to minimize differences in haptic
  and sound while typing. The order for the keyboards and texts for the
  individual tests is randomized and across subjects counterbalanced to mitigate
  order effects \cite{statist_counterbalancing}. \textbf{(total: 65 min)}
  \begin{enumerate}
    \item First typing test with \gls{KB} A (5 min) \\
     Follow-up ISO keyboard comfort questionnaire (ISO9241-410) (5 min)
    \item Second typing test with \gls{KB} A (5 min) \\
     Follow-up ISO keyboard comfort questionnaire (ISO9241-410) (5 min)
    \item First typing test with \gls{KB} B (5 min) \\
     Follow-up ISO keyboard comfort questionnaire (ISO9241-410) (5 min)
    \item Second typing test with \gls{KB} B (5 min) \\
     Follow-up ISO keyboard comfort questionnaire (ISO9241-410) (5 min)
    \item First typing test with \gls{KB} C (5 min) \\
     Follow-up ISO keyboard comfort questionnaire (ISO9241-410) (5 min)
    \item Second typing test with \gls{KB} C (5 min) \\
     Follow-up ISO keyboard comfort questionnaire (ISO9241-410) (5 min)
  \end{enumerate}
  \item \textbf{Main-Test part 2 (H4):} Another typing test to compare the
  results of keyboards with uniform actuation force to keyboards with adjusted
  actuation force per finger/key. Typing tests (2x 5 min + 5 min break in
  between tests) \textbf{(total: (i) 60 min / (ii) 45 min)}
  \begin{enumerate}
    \item \textbf{Alternative Methods:}
    \begin{enumerate}
      \item \textbf{Personalized keyboard:} Typing sample text on an analog
      keyboard with high actuation force (150 \gls{g}) (less accurate) or on a
      normal keyboard which is placed on top of a force plate (more accurate) to
      measure difference in typing force per finger and key. The subject should
      be forced to press every relevant key (letters, digits, common special
      characters) at least 5 times (Measurement: 15 min, Keyboard adjustment: 15
      min)
      \item \textbf{Adjusted keyboard:} Keyboard that is equipped with different
      zones of keyswitches that use appropriate actuation forces according to
      finger strength differences and key position. (Keyboard adjustment: 15 min)
    \end{enumerate}
      \item Familiarization with the keyboard (10 min)
      \item First typing test on the personalized/adjusted keyboard (5 min) \\
       Follow-up ISO keyboard comfort questionnaire (ISO9241-410) (5 min)
      \item Second typing test on the personalized/adjusted keyboard (5 min) \\
       Follow-up ISO keyboard comfort questionnaire (ISO9241-410) (5 min)
  \end{enumerate}
\end{enumerate}

All tests could be enhanced with the use of \gls{EMG} measurement and/or additional force measurement (with force plates) during the typing tests.

This test scenario is inspired by the tests conducted by \cite{kim_typingforces}.