\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 84\% of European households
as well as nearly half of the worldwide households have access to at least one
computer \cite{eurostat_hous_w_comp, itu_hh_w_comp}. Even 153 years after the
first typewriter was patented \cite{noyes_qwerty} people still mostly use
identical looking 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, which can cause discomfort
and increase the risk for \gls{WRUED} \cite{pascarelli_wrued,
  ccfohas_wrued}. Previous research has shown, that the actuation force, which
is the force required to generate a keypress, is directly related to the actual
force an individual generates to press a specific key
\cite{gerard_keyswitch}. Also, the individual fingers are not capable of
exerting identical force and therefore fatigue must be higher for weaker fingers
\cite{bretz_finger, martin_force, baker_kinematics, dickson_finger}. There are
various designs for alternative keyboards by e.g.,
Maltron\footnote{\url{https://www.maltron.com/store/c47/Dual_Hand_Keyboards.html}},
Ergodox\footnote{\url{https://www.ergodox.io/}}, Kenesis
\footnote{\url{https://kinesis-ergo.com/keyboards/advantage2-keyboard/}},
etc. which, because of the often unusual layouts and extra keys for the thumbs,
all require the typist to adjust to a completely new way of typing and therefore
could reduce productivity during this adjustment phase. Additionally, a study by
Baker et al. (n = 77) revealed, that even after several months of using a
keyboard with an alternative design, in terms of usability, participants still
preferred the traditional design because of its superb usability
\cite{baker_ergo2}. With these insights, the uniformity of actuation force
across conventional keyboards may be a potential characteristic that could be
improved on, to reduce the strain on weaker fingers and thus reduce fatigue and
increase comfort. Therefore, a keyboard with, per key, adjusted actuation force,
depending on the finger usually operating the key, might be a feasible solution
without the requirement for typists to invest in higher priced alternative
keyboards, which also require additional familiarization. To become a successful
alternative, the adjusted keyboard design has to perform equally good or even
better than existing conventional keyboard designs, while also enhancing the user
experience during usage. These requirements led to the research question of
this thesis:

\vspace{1em}
\begin{tabular}{p{0.3cm} p{0.5cm} p{13cm} p{0.5cm}}
  & \textbf{\large RQ}	& {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}

If this question could be positively answered, companies producing keyboards
could implement the proposed adjustments in actuation force into existing
manufacturing processes and thereby make adjusted keyboard designs broadly
available and potentially keep the retail prices acceptably low.



% This raises the question, if 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.

% 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.

% Input tasks are not only restricted to pure data entry but also include complex
% inputs required by games.