diff --git a/abstractEN.tex b/abstractEN.tex index 09d2c1a..e3bfbc8 100644 --- a/abstractEN.tex +++ b/abstractEN.tex @@ -6,22 +6,22 @@ or at home, the keyboard is still, the main input device for almost anyone that interacts with a computer. However, at some point, many people experience discomfort or even pain while using a keyboard because of the many small and repetitive movements the fingers have to do to operate it. Therefore, in this -thesis we try to evaluate an alternative, non-uniform keyboard design, where -each individual \textit{mechanical} keyswitch is equipped with a spring, that -features a resistance, appropriate for the specific finger usually operating -it. The idea behind this adjusted design is to particularly reduce the load on -weaker fingers and still pertain or even enhance typing -performance. Additionally, we try to answer the question, whether or not a -keyboard with, per finger, adjusted actuation force has a positive impact on -efficiency and overall satisfaction. Thus, we evaluated the current availability -of resistances for mechanical keyswitches and conducted a preliminary telephone -interview (n = 17) to assess preferences, use-cases and previous experiences -with keyboards. Further, we ran another preliminary experiment, where we -measured the maximum applicable force for each finger in different positions -related to keyboarding as a basis for our adjusted keyboard design. Lastly, -during a three week laboratory user study with twenty-four participants, the -adjusted keyboard design and three traditional keyboards with 35\,g, 50\,g and 80 -g actuation force were compared to each other in terms of performance and user +thesis we try to evaluate an alternative, non-uniform keyboard design where each +individual \textit{mechanical} keyswitch is equipped with a spring that features +a resistance appropriate for the specific finger usually operating it. The idea +behind this adjusted design is to particularly reduce the load on weaker fingers +and still pertain or even enhance typing performance. Additionally, we try to +answer the question, whether or not a keyboard with, per finger, adjusted +actuation force has a positive impact on efficiency and overall +satisfaction. Thus, we evaluated the current availability of resistances for +mechanical keyswitches and conducted a preliminary telephone interview (n = 17) +to assess preferences, use-cases and previous experiences with +keyboards. Further, we ran another preliminary experiment, where we measured the +maximum applicable force for each finger in different positions related to +keyboarding as a basis for our adjusted keyboard design. Lastly, during a three +week laboratory user study with twenty-four participants, the adjusted keyboard +design and three traditional keyboards with 35\,g, 50\,g and 80 g actuation +force were compared to each other in terms of performance and user satisfaction. The statistical analysis revealed, that especially error rates are positively influenced by higher actuation forces and that keyboards with neither too heavy nor to light resistance generally perform the best in terms of typing diff --git a/acknowledgments.tex b/acknowledgments.tex index 0345386..a4a7fa3 100644 --- a/acknowledgments.tex +++ b/acknowledgments.tex @@ -1,4 +1,23 @@ %----------Danksagung/Acknowledgments-------------------------------------------------------------- \addsec{Acknowledgments} -Hello (: +Firstly, I want to thank all the 53 people that either participated in the over +two hour long main study, the preliminary finger force study, the preliminary +telephone interview or the crowdsourcing of the required texts for merely a +thanks or some 3D-printed goodies. + +Furthermore, I want to thank my supervisor Prof. Dr. techn. Priv.-Doz. Andreas +Riener for his great input and guidance throughout this whole thesis. The always +fast and candid support regarding all my concerns was highly appreciated! + +Further, I want to thank Prof. Dr. rer. nat. Franz Regensburger for the initial +feedback about all my ideas for a thesis, which helped me to ultimately decide +on this topic. + +Additionally, I want to thank Eliis Lohoff, Nikola Brandl and Lukas Hanser for +proofreading my thesis. + +Moreover, I want thank my girlfriend, mother and grandma for the emotional +support and all the encouraging words during my whole studies. + +― Philip \ No newline at end of file diff --git a/chap2/literature_review.tex b/chap2/literature_review.tex index e5480d5..ef583be 100644 --- a/chap2/literature_review.tex +++ b/chap2/literature_review.tex @@ -55,7 +55,7 @@ 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. The keyboards feature different enclosures and keycaps, which are +appearance. The keyboards feature different enclosures and keycaps. Keycaps 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 @@ -120,8 +120,8 @@ 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 +stem, the spring gets contracted and the stem moves downwards. Thereby, it 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 diff --git a/chap4/methodology.tex b/chap4/methodology.tex index 8941f73..a0ebd9b 100644 --- a/chap4/methodology.tex +++ b/chap4/methodology.tex @@ -305,12 +305,13 @@ keyboard?.''} \subsubsection{Method} \label{sec:main_method} In our laboratory study, twenty-four participants were required to perform two -typing test with each of the four keyboards provided by us and two extra typing -test with their own keyboards as a reference. The four keyboards differed only +typing tests with each of the four keyboards provided by us and two extra typing +tests with their own keyboards as a reference. The four keyboards differed only in actuation force and were the independent variable. The dependent variable -were, typing speed (\gls{WPM} and \gls{KSPS}), error rate (\gls{CER}, \gls{TER}) -and satisfaction (preference, usability, comfort, forearm muscle activity -measured via \gls{EMG}, post experiment semi structured interview and ux-curves) +were, typing speed (\gls{WPM} and \gls{KSPS}), error rate (\gls{CER}, +\gls{TER}), forearm muscle activity measured via \gls{EMG} and satisfaction +(preference, usability, comfort, post experiment semi structured interview and +ux-curves). \subsubsection{Participants} \label{sec:main_participants} @@ -507,12 +508,12 @@ 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 (\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 a \gls{VAS} ranging from 0 to 100 -(\glsfirst{PKQ})\cite{lewis_vas}. Due to 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, the short -version of the \gls{UEQ} was selected \cite{schrepp_ueq_handbook}. +an additional question―\textit{``How satisfied have you been with this + keyboard?''}―that could be answered with the help of a \gls{VAS} ranging from +0 to 100 (\glsfirst{PKQ})\cite{lewis_vas}. Due to 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, the +short version of the \gls{UEQ} was selected \cite{schrepp_ueq_handbook}. \textbf{Post Experiment Interview \& \Gls{UX Curve}s} diff --git a/chap5/results.tex b/chap5/results.tex index dd82853..ab9edc8 100644 --- a/chap5/results.tex +++ b/chap5/results.tex @@ -358,7 +358,7 @@ the right flexor muscle (n = 22). We found no significant differences in \gls{EMG} measurements. Further, we analyzed the effect of the individual keyboards on \%\gls{MVC}s separately for first and second typing tests (Tn\_1 \& Tn\_2, n := 1, ..., 4), but did not find any statistically significant results -as well. Lastly, we analyzed possible differences between \%\gls{MVC} +either. Additionally, we analyzed possible differences between \%\gls{MVC} measurements of first and second typing tests for each individual keyboard, using either dependent T-tests or Wilcoxon Signed Rank Tests. There were no statistically significant differences in \%\gls{MVC} between the first and the @@ -367,11 +367,11 @@ test keyboards of the mean values for both typing tests combined can be observed in Table \ref{tbl:sum_tkbs_emg}. Lastly, we created histograms (Figure \ref{fig:max_emg_tkbs}) for each of the observed muscle groups, that show the number of times a keyboard yielded the highest \%\gls{MVC} out of all keyboards -for each participant. We found, that \textit{Athena} most frequently ($\approx$45\,\%) -produced the highest extensor muscle activity for both arms. The highest muscle -activity for both flexor muscle groups was evenly distributed among all test -keyboards with a slight exception of \textit{Nyx}, which produced the highest -\%\gls{MVC} only in ~14\,\% of participants. +for each participant. We found that \textit{Athena} most frequently +($\approx$45\,\%) produced the highest extensor muscle activity for both +arms. The highest muscle activity for both flexor muscle groups was evenly +distributed among all test keyboards with a slight exception of \textit{Nyx}, +which produced the highest \%\gls{MVC} only in ~14\,\% of participants. \begin{figure}[H] \centering @@ -449,7 +449,7 @@ keyboards with a slight exception of \textit{Nyx}, which produced the highest \label{sec:res_kcq} The \glsfirst{KCQ} was filled out by the participants after each individual typing test. The questionnaire featured twelve questions regarding the -previously used keyboard which are labelled as follows: +previously used keyboard which are labeled as follows: \begin{table}[H] \centering @@ -524,7 +524,7 @@ eight questions on a 7-point Likert scale, which formed two scales (pragmatic, hedonic). Additionally we added one extra question that could be answered on a \glsfirst{VAS} from 0 to 100. The survey was filled out after both tests with a keyboard have been completed. The questions of our modified \gls{UEQ-S} were -labelled as follows: +labeled as follows: \begin{table}[H] \centering @@ -648,25 +648,25 @@ stable if \gls{SP} = \gls{EP} (margin of $\pm$ 1 mm). One curve can either represent one typing test (C1 or C2) or the whole experience with one keyboard over the course of both typing tests (C12). All curves can be observed in Appendix \ref{app:uxc} and the resulting slopes for all curve types are shown in -Figure \ref{fig:res_uxc}. During the semi-structured interview, we asked the +Figure \ref{fig:res_uxc}. During the semi-structured interview we asked the participants to rank the keyboards from 1 (favorite) to 5 (least favorite). If in doubt, participants were allowed to place two keyboards on the same rank. Further, we asked some participants (n = 19) to also rank the keyboards from lowest actuation force (one) to highest actuation force (five). The participants own keyboard was four times more often placed first than any other -keyboard. \textit{Hera} was the only keyboard, that never got placed fifth and +keyboard. \textit{Hera} was the only keyboard that never got placed fifth and except for \textit{Own}, was the most represented keyboard in the top three. The -ranking of the perceived actuation force revealed, that participants were able -to identify \textit{Nyx} (35\,g) and \textit{Athena} (80\,g) as the keyboards with -the lowest and highest actuation force respectively. All results for both +ranking of the perceived actuation force revealed that participants were able +to identify \textit{Nyx} (35\,g) and \textit{Athena} (80\,g) as the keyboards +with the lowest and highest actuation force respectively. All results for both rankings are visualized in Figure \ref{fig:res_interview}. Lastly, we analyzed the recordings of all interviews and found several similar statements about -specific keyboards. Twelve participants noted, that because of the new form +specific keyboards. Twelve participants noted that because of the new form factor of the test keyboards, additional familiarization was required to feel comfortable. Nine of those specifically mentioned the height of the keyboard as the main difference. Fourteen subjects reported―\textit{``Because Nyx had such a low resistance, I kept making mistakes!''}. Four participants explicitly -noted, that \textit{Hera} felt very pleasant and two subjects mentioned +noted that \textit{Hera} felt very pleasant and two subjects mentioned \textit{``I had really good flow.''} and \textit{``It somehow just felt right''}. Ten participants reported, that typing on \textit{Athena} was exhausting. \textit{Aphrodite} was not mentioned as often as the other keyboards diff --git a/chap6/discussion.tex b/chap6/discussion.tex index 28e5c25..f600835 100644 --- a/chap6/discussion.tex +++ b/chap6/discussion.tex @@ -9,38 +9,39 @@ question \textit{``Does an adjusted actuation force per key have a positive \subsection{Impact of Actuation Force on Typing Speed} \label{sec:dis_speed} -Our main experiment yielded, that there are differences in typing speed for both +Our main experiment yielded that there are differences in typing speed for both metrics related to transcribed text we measured―namely \glsfirst{WPM} and \glsfirst{AdjWPM}. Especially the keyboard with the lowest uniform actuation force of 35\,g―\textit{Nyx}―performed worse than all other keyboards. In terms of \gls{WPM}, \textit{Nyx (35\,g)} was on average 4.1\,\% slower than -\textit{Athena (80\,g)} and \textit{Aphrodite (50\,g)} and 4.8\,\% slower than the -adjusted keyboard \textit{Hera (35 - 60\,g)}. Similarly, for \gls{AdjWPM}, +\textit{Athena (80\,g)} and \textit{Aphrodite (50\,g)} and 4.8\,\% slower than +the adjusted keyboard \textit{Hera (35 - 60\,g)}. Similarly, for \gls{AdjWPM}, \textit{Nyx} was 4.3\,\% slower than \textit{Athena} and \textit{Aphrodite} and -4.9\,\% slower than \textit{Hera}. The 4\,\% to 5\,\% difference in \gls{WPM} and -\gls{AdjWPM} in our sample account for approximately 2 words per minute. When -extrapolated with the mean daily keyboard usage of 6.69 hours reported by our -participants, this difference would be as big as 803 words, which when put into -perspective, is equivalent to roughly two full pages of only written content -(11pt font size). Although, this specific example would assume constant typing -for 6.69 hours, it is still a useful estimate of the loss in productivity under -normal working conditions over the course of several days. These differences in -\gls{WPM} and \gls{AdjWPM} could be explained by the higher error rates and -thereby the loss of ``typing flow'' we discuss in the next section. \gls{KSPS} -reflects the raw input speed by including backspaces and previously deleted -characters. The reason we included \gls{KSPS} in our analysis was to reveal -possible differences in the physical speed participants type on a keyboard and -not to further asses speed in the sense of productivity. We could not find any -statistically significant differences in \gls{KSPS} but saw a trend, indicating -that subjects typed a bit slower (< 3\,\%) on \textit{Athena (80\,g)} compared to -\textit{Aphrodite (50\,g)} and \textit{Hera (35 - 60\,g)}. With the differences -in metrics that are commonly used to measure typing speed more closely related -to productivity (\gls{WPM}, \gls{AdjWPM}) and the trends that indicate a slight -difference in operating speed we could have accepted our hypothesis. However, -with the relation between error rate and typing speed described in the next -section and the thereby rather indirect effect of the actuation force, we can -only partially accept our hypothesis that a difference solely in actuation -force, has an impact on typing speed. +4.9\,\% slower than \textit{Hera}. The 4\,\% to 5\,\% difference in \gls{WPM} +and \gls{AdjWPM} in our sample account for approximately two words per +minute. When extrapolated with the mean daily keyboard usage of 6.69 hours +reported by our participants, this difference would be as big as 803 words, +which when put into perspective, is equivalent to roughly two full pages of only +written content (11pt font size). Although, this specific example would assume +constant typing for 6.69 hours, it is still a useful estimate of the loss in +productivity under normal working conditions over the course of several +days. These differences in \gls{WPM} and \gls{AdjWPM} could be explained by the +higher error rates and thereby the loss of ``typing flow'' we discuss in the +next section. \gls{KSPS} reflects the raw input speed by including backspaces +and previously deleted characters. The reason we included \gls{KSPS} in our +analysis was to reveal possible differences in the physical speed participants +type on a keyboard and not to further asses speed in the sense of +productivity. We could not find any statistically significant differences in +\gls{KSPS} but saw a trend, indicating that subjects typed a bit slower (< +3\,\%) on \textit{Athena (80\,g)} compared to \textit{Aphrodite (50\,g)} and +\textit{Hera (35 - 60\,g)}. With the differences in metrics that are commonly +used to measure typing speed more closely related to productivity (\gls{WPM}, +\gls{AdjWPM}) and the trends that indicate a slight difference in operating +speed we could have accepted our hypothesis. However, with the relation between +error rate and typing speed described in the next section and the thereby rather +indirect effect of the actuation force, we can only partially accept our +hypothesis that a difference solely in actuation force, has an impact on typing +speed. \begin{phga_hyp*}[1 $\rightarrow$ \cmark\kern-1.1ex\raisebox{.7ex}{\rotatebox[origin=c]{125}{--}}] Actuation force has an impact on typing speed (efficiency - speed). @@ -59,17 +60,18 @@ force, has an impact on typing speed. As already briefly mentioned in Section \ref{sec:dis_speed}, measured error rates like \glsfirst{UER}, \glsfirst{CER} and \glsfirst{TER} differed especially between \textit{Nyx (35\,g)} and the other test keyboards. The statistical -analyses further revealed, that \textit{Athena}, the keyboard with the highest +analyses further revealed that \textit{Athena}, the keyboard with the highest actuation force of 80\,g, produced on average 1\,\% less \gls{TER} than \textit{Hera (35 - 60\,g)} and \textit{Aphrodite (50\,g)} and 3\,\% less than -\textit{Nyx (35\,g)}. Furthermore, \textit{Hera} and \textit{Aphrodite} both had a -2\,\% lower \gls{TER} than \textit{Nyx}. Additionally to the quantitative results, -fourteen of the twenty-four participants also reported, that \textit{Nyx's} -light actuation force was the reason for many accidental key presses. It further -stood out, that as shown in Figure \ref{fig:max_opc_ter}, \textit{Athena} was -the most accurate keyboard for 58\,\% of participants and also more accurate than -keyboard \textit{Own} for eleven of the subjects. Overall, this concludes, that -a higher actuation force has a positive impact on error rate. +\textit{Nyx (35\,g)}. Furthermore, \textit{Hera} and \textit{Aphrodite} both had +a 2\,\% lower \gls{TER} than \textit{Nyx}. Additionally to the quantitative +results, fourteen of the twenty-four participants also reported, that +\textit{Nyx's} light actuation force was the reason for many accidental key +presses. It further stood out that, as shown in Figure \ref{fig:max_opc_ter}, +\textit{Athena} was the most accurate keyboard for 58\,\% of participants and +also more accurate than keyboard \textit{Own} for eleven of the +subjects. Overall, this concludes that a higher actuation force has a positive +impact on error rate. \begin{phga_hyp*}[2 $\rightarrow$ \cmark] Higher key actuation force decreases typing errors compared to lower key @@ -80,13 +82,13 @@ a higher actuation force has a positive impact on error rate. The higher error rates and the possibility to correct erroneous input could have also been a factor that led to lower \textit{WPM}. To evaluate the likelihood of -this additional relation, we conducted a \gls{LRT} of fixed effects for our +this additional relation we conducted a \gls{LRT} of fixed effects for our linear mixed-effects model with two random effects (participant and first/second typing test), fixed effect \gls{TER} and response variable \gls{WPM}. The results of the \gls{LRT} ($\chi^2(1)$ = 110.44, p = 0.00000000000000022) together with the trends of lower \gls{WPM} with increasing \gls{TER}, visible -in Figure \ref{fig:reg_ter_wpm}, suggest, that the \gls{TER} indeed had an -impact on \gls{WPM}. This could have been, because every time an error was made, +in Figure \ref{fig:reg_ter_wpm}, suggest that the \gls{TER} indeed had an +impact on \gls{WPM}. This could have been because every time an error was made, almost all participants decided to correct it right away. With a higher error rate, this obviously leads to many short interruptions and an increased number of characters that are not taken into account when computing the \gls{WPM} @@ -108,7 +110,7 @@ We tried to narrow down the rather broad term ``satisfaction'' to individual categories that we, with the information gathered through our literature review and telephone interviews, defined as necessary for a positive user experience while using a keyboard \cite{giese_sati}. We decided for the following metrics -to evaluate, whether or not a user experience with a keyboard that features +to evaluate whether or not a user experience with a keyboard that features lighter actuation forces was more satisfactory: \begin{table}[H] @@ -129,26 +131,26 @@ lighter actuation forces was more satisfactory: As described in Section \ref{sec:res_ueqs}, we could not find statistically significant differences for any of the test keyboards regarding the pragmatic scale of the \gls{UEQ-S}. From visual assessment of the graph shown in Figure -\ref{fig:ueq_tkbs_res} we could conclude, that there is a slight trend towards a +\ref{fig:ueq_tkbs_res} we could conclude that there is a slight trend towards a more positive rating for keyboards that utilized keyswitches with higher actuation forces than \textit{Nyx (35\,g)}. This trend in the opposite direction -of our hypothesized outcome, that lighter actuation force leads to more user +of our hypothesized outcome that lighter actuation force leads to more user satisfaction, could be due to the longer familiarization time required for keyboards with very light actuation force \cite{gerard_keyswitch}. \textbf{[\xmark] Additional Question of Satisfaction with Keyboard} The results deduced from the additional question \textit{``How satisfied have - you been with this keyboard?''}, which could be answered on a \glsfirst{VAS} + you been with this keyboard?''}, which were answered on a \glsfirst{VAS} from 0 to 100 after both tying tests with a keyboard, suggested that \textit{Nyx (35\,g)}, the keyboard with the lightest actuation force and also \textit{Athena (80\,g)} the keyboard with the highest actuation force, were rated significantly worse than \textit{Aphrodite (50\,g)}. Additionally, \textit{Hera - (35 - 60\,g)}, the adjusted keyboard showed a trend towards a significantly -better rating than \textit{Nyx}. These results indicate, that neither of the + (35 - 60\,g)}, the adjusted keyboard, showed a trend towards a significantly +better rating than \textit{Nyx}. These results indicate that neither of the keyboards with extreme actuation forces were perceived as a overwhelmingly pleasant keyboard to use during our typing tests. This is further supported by -the visualisation of the mean ratings in Figure \ref{fig:res_tkbs_sati} where +the visualization of the mean ratings in Figure \ref{fig:res_tkbs_sati} where the average ratings for \textit{Aphrodite} and \textit{Hera} were approximately 10 points higher than those for \textit{Nyx} and \textit{Athena}. @@ -159,11 +161,11 @@ questions related to effort or fatigue while operating a keyboard, \textit{Athena (80\,g)} received significantly lower ratings than the other test keyboards. Additionally to the measured differences in error rates discussed in Section \ref{sec:dis_error}, we discovered that participants also perceived the -accuracy of \textit{Athena (80\,g)} and \textit{Aphrodite (50\,g)} higher compared -to \textit{Nyx (35\,g)}. Similarly to the results discussed in the last +accuracy of \textit{Athena (80\,g)} and \textit{Aphrodite (50\,g)} higher +compared to \textit{Nyx (35\,g)}. Similarly to the results discussed in the last paragraph, the scores of the two keyboards with extreme actuation forces, -\textit{Nyx (35\,g)} and \textit{Athena (80\,g)} fluctuated quite a bit and on -average those two keyboards scored lower than \textit{Aphrodite (50\,g)} or +\textit{Nyx (35\,g)} and \textit{Athena (80\,g)}, fluctuated quite a bit and, on +average both keyboards scored lower than \textit{Aphrodite (50\,g)} or \textit{Hera (35 - 60\,g)} (Figure \ref{fig:kcq_tkbs_res}). Thereby, these results do not indicate a clear trend towards enhanced user experience when using keyboards with lower actuation forces. @@ -191,15 +193,15 @@ Lastly, we analysed all recordings of the post-experiment interviews and categorized the feedback given for each keyboard into positive and negative responses. We then calculated a ratio of these responses, which can be seen in Figure \ref{fig:ratio_interview}, to evaluate preferences towards specific -keyboards, that could not be expressed by our participants through any other +keyboards that could not be expressed by our participants through any other supplied method during the experiment. Like all other factors we identified as reasonable indicators for satisfaction, these ratios yielded, that neither \textit{Athena (80\,g)} nor \textit{Nyx (35\,g)} received more positive than negative feedback. It should be noted, that previous research has shown that people tend to remember and process bad experiences more thorough than good ones, which could be a reason for the increased number of negative feedback for -\textit{Nyx} and \textit{Athena} but would also indicate a worse experience with -those two keyboards \cite{baumeister_bad}. +\textit{Nyx} and \textit{Athena}, but would also indicate a worse experience +with those two keyboards \cite{baumeister_bad}. \begin{figure}[H] \centering @@ -211,16 +213,16 @@ those two keyboards \cite{baumeister_bad}. \textbf{Conclusion} -Contrary to the responses of our preliminary telephone interview, where 76\,\% of -attendees preferred a keyboard with light actuation force, none of the factors -we defined as relevant for user satisfaction suggests, that keyboards with lower -actuation force are more satisfactory to use than keyboards with higher -actuation force. Therefore, we have to fully reject our hypothesis. We can -conclude thought, that keyboards with actuation forces in between those two +Contrary to the responses of our preliminary telephone interview, where 76\,\% +of attendees preferred a keyboard with light actuation force, none of the +factors we defined as relevant for user satisfaction suggests that keyboards +with lower actuation force are more satisfactory to use than keyboards with +higher actuation force. Therefore, we have to fully reject our hypothesis. We +can conclude thought that keyboards with actuation forces in between those two extremes (35\,g / 80\,g), are persistently perceived as more pleasant to use and -that ratings keyboards with extreme actuation forces are highly influenced by -personal preference, which is indicated by the high fluctuation of almost all -responses regarding our evaluated factors. +that ratings of keyboards with extreme actuation forces are highly influenced by +personal preference. The latter is indicated by the high fluctuation of almost +all responses regarding our evaluated factors. \begin{phga_hyp*}[3 $\rightarrow$ \xmark] Keys with lower actuation force are perceived as more satisfactory to type @@ -229,12 +231,12 @@ responses regarding our evaluated factors. \subsection{Impact of Actuation Force on Muscle Activity} \label{sec:dis_emg} -In contrast to other studies that suggested, that actuation force has an impact +In contrast to other studies that suggested that actuation force has an impact on muscle activity, we could not identify significant differences in terms of \% -of \glsfirst{MVC} for any of our \gls{EMG} measurements. Only a slight trend, -that \textit{Nyx (35\,g)} produced the highest flexor \%\gls{MVC} for only 14\,\% -of participants, could be interpreted as anecdotal evidence towards our -hypothesis, that actuation force has an impact on muscle activity. Therefore we +of \glsfirst{MVC} for any of our \gls{EMG} measurements. Only a slight trend +that \textit{Nyx (35\,g)} produced the highest flexor \%\gls{MVC} for only +14\,\% of participants, could be interpreted as anecdotal evidence towards our +hypothesis that actuation force has an impact on muscle activity. Therefore, we have to reject our hypothesis. \begin{phga_hyp*}[4 $\rightarrow$ \xmark] @@ -251,7 +253,7 @@ As discussed in the previous sections, there were no statistically significant differences in terms of satisfaction for any of the test keyboards, including our adjusted keyboard \textit{Hera}. Still, the rather unconventional design choice of non-uniform actuation forces across a keyboard did not negatively -influence the satisfaction compared to \textit{Aphrodite} which was often +influence the satisfaction compared to \textit{Aphrodite}, which was often perceived as equivalent to the participant's own keyboard. In fact, \textit{Hera} was the keyboard with the most occurrences in the top three, tied first place with \textit{Aphrodite} and was never ranked 4th place during the @@ -263,10 +265,10 @@ familiarization period required by keyboards with lighter actuation forces reported a currently present disease of the left arm and wrist (Syndrome Sudeck, complex regional pain syndrome (CRPS)), ranked Hera 30 points higher than all other keyboards. \textit{I3Z4XI7H} also reported in the post-experiment -interview, that \textit{Hera} was surprisingly pleasant to use and that pain was +interview that \textit{Hera} was surprisingly pleasant to use and that pain was significantly lower than with all other keyboards including \textit{Own}. However, because of the nearly identical scores to -\textit{Aphrodite} in almost all categories, we have to reject our hypothesis, +\textit{Aphrodite} in almost all categories, we have to reject our hypothesis that an adjusted keyboard is more satisfactory to use than standard keyboards. \begin{phga_hyp*}[7 $\rightarrow$ \xmark] @@ -274,19 +276,20 @@ that an adjusted keyboard is more satisfactory to use than standard keyboards. to standard keyboards. \end{phga_hyp*} -Similarly, the resulting error rates measured for \textit{Hera (35 - 60\,g)} were -close to equal to the results of \textit{Aphrodite (50\,g)} and for speed related -metrics between those two keyboards only slight improvements while using -\textit{Hera} in \gls{WPM} (0.8\,\%), \gls{AdjWPM} (0.6\,\%) and \gls{KSPS} (1\,\%)― -that were not statistically significant―were recorded during our experiment. It -was still interesting to see, that \textit{Hera} was the fastest, out of all -four test keyboards, for eleven (45\,\%) out of the twenty-four subjects and that -albeit the usage of 30\,\% keyswitches\footnote{That were actually pressed during - our typing tests} that required 35 - 40\,g actuation force, which is similar to -the actuation force of \textit{Nyx (35\,g)}, we did not see comparably high error -rates. Because of the lacking evidence, that an adjusted keyboard produces less -errors or supports the typist in achieving higher typing speeds, we have to -reject our two hypotheses regarding those improvements. +Similarly, the resulting error rates measured for \textit{Hera (35 - 60\,g)} +were close to equal to the results of \textit{Aphrodite (50\,g)} and for speed +related metrics between those two keyboards only slight improvements while using +\textit{Hera} in \gls{WPM} (0.8\,\%), \gls{AdjWPM} (0.6\,\%) and \gls{KSPS} +(1\,\%)― that were not statistically significant―were recorded during our +experiment. It was still interesting to see, that \textit{Hera}, out of all four +test keyboards, was the fastest for eleven (45\,\%) out of the twenty-four +subjects and that albeit the usage of 30\,\% keyswitches\footnote{That were + actually pressed during our typing tests} that required 35 - 40\,g actuation +force, which is similar to the actuation force of \textit{Nyx (35\,g)}, we did +not see comparably high error rates. Because of the lacking evidence, that an +adjusted keyboard produces less errors or supports the typist in achieving +higher typing speeds, we have to reject our two hypotheses regarding those +improvements. \begin{phga_hyp*}[5 $\rightarrow$ \xmark] An adjusted keyboard improves typing speed compared to standard keyboards @@ -298,7 +301,7 @@ reject our two hypotheses regarding those improvements. to standard keyboards. \end{phga_hyp*} -Our experiment basically revealed, that keyboards which utilized keyswitches +Our experiment basically revealed that keyboards which utilized keyswitches with actuation forces that were neither too light (35\,g) nor too heavy (80\,g), generally outperformed keyboards which featured those extreme actuation forces. In the following section, we elaborate on possible limitations of our diff --git a/chap7/conclusion.tex b/chap7/conclusion.tex index 68956cc..0c39d31 100644 --- a/chap7/conclusion.tex +++ b/chap7/conclusion.tex @@ -16,21 +16,21 @@ actuation force. Especially the keyboard with very low actuation force, \textit{Nyx (35\,g)}, which also had the highest average error rate was significantly slower than all other keyboards. Therefore, we investigated, if there is a connection between high error rates and stagnating typing speed and -found, that in general, the error rate was a factor for lower input +found that in general, the error rate was a factor for lower input rates. Neither the satisfaction nor the muscle activity was significantly influenced solely by the actuation. -In conclusion, our study showed, that the keyboard with non-uniform actuation +In conclusion, our study showed that the keyboard with non-uniform actuation forces―\textit{Hera (35 - 60\,g)}―was not able to improve the overall typing experience significantly enough to supersede existing designs, but was still a -viable alternative to all traditional keyboards we tested. It could be possible, +viable alternative to all traditional keyboards we tested. It could be possible that due to the unconventional force distribution, that is similar to keyboards with very light actuation force, the muscle activity while using \textit{Hera} could decrease when users are given more time to adapt to this keyboard \cite{gerard_keyswitch}. Additionally, we found that keyboards with either very -high (80\,g) or very low (35\,g) actuation forces had the most influence on typing -related metrics, when compared to the more commonly sold keyboards with around -50\,g to 60\,g actuation force. In the next sections we identify possible +high (80\,g) or very low (35\,g) actuation forces had the most influence on +typing related metrics, when compared to the more commonly sold keyboards with +around 50\,g to 60\,g actuation force. In the next sections we identify possible limitations and propose some ideas on how to reevaluate custom keyboard designs in future studies. @@ -45,16 +45,16 @@ the researcher was in the same room, the limited time for the individual typing tests and the rather short breaks in between typing tests, could have influenced some subjects by inducing unnecessary stress. Another limitation related to the preliminary finger strength study, was the very small number of participants (n -= 6). Although we measured the finger strengths in different positions for 50\,\% -female and male participants, the age distribution was not diverse (M = 24) and -with a higher number of subjects, the results would have been much more += 6). Although we measured the finger strengths in different positions for +50\,\% female and male participants, the age distribution was not diverse (M = +24) and with a higher number of subjects, the results would have been much more reliable. Similarly, the number and diversity in occupation of participants could have been higher for our main study (n = 24) to yield even more meaningful results. The low number of participants in general was partly due to the ongoing COVID-19 pandemic. Lastly, we could have used more linear mixed models during our statistical analysis, to be able to make statements about the influence of other factors e.g., age, gender, average daily keyboard usage, etc., on speed, -error rate and satisfaction. +error rate or satisfaction. \subsection{Future work} \label{sec:fw} @@ -62,17 +62,18 @@ We propose, that in further research related to keyboards with non-uniform actuation force (adjusted keyboards), participants should test several different adjusted keyboards and the results should be compared to one identical looking keyboard that utilizes a uniform layout of keyswitches with an actuation force -of 50\,g to 65\,g. Further, different adjusted layouts, with e.g. higher or lower -base actuation force than 50\,g could be used to calculate the individual spring -resistances used for each key or a similar layout to the one used in +of 50\,g to 65\,g. Further, different adjusted layouts, with e.g. higher or +lower base actuation force than 50\,g could be used to calculate the individual +spring resistances used for each key or a similar layout to the one used in Realforce\footnote{\url{https://www.realforce.co.jp/en/products/}} keyboards, could be compared to each other. Furthermore, long term studies with adjusted -keyboards, where participants use the adjusted keyboard for 3 to 4 months and -then use a uniform keyboard they prefer for another 3 to 4 months as their daily -driver, could yield more accurate results, due to the chance to fully adapt to -the individual keyboards. During those months \gls{EMG} and typing related -metrics should be measured on a regular basis. Lastly, it would be interesting -to investigate if an adjusted keyboard can reduce pain or at least enhance -comfort for typists with pre-existing diseases influenced by typing activities -(disorders of the upper extremity), since one of our participants with a similar -disease reported a great reduction in pain while using \textit{Hera}. +keyboards where participants use the adjusted keyboard for three to four months +and then use a uniform keyboard they prefer for another three to four months as +their daily driver, could yield more accurate results, due to the chance to +fully adapt to the individual keyboards. During those months \gls{EMG} and +typing related metrics should be measured on a regular basis. Lastly, it would +be interesting to investigate if an adjusted keyboard can reduce pain or at +least enhance comfort for typists with pre-existing diseases influenced by +typing activities (disorders of the upper extremity), since one of our +participants with a similar disease reported a great reduction in pain while +using \textit{Hera}. diff --git a/confidentialityClause.tex b/confidentialityClause.tex deleted file mode 100644 index 48f7b97..0000000 --- a/confidentialityClause.tex +++ /dev/null @@ -1,12 +0,0 @@ -%----------Sperrvermerk/Confidentiality clause------------------------------------------------------------ - - -\addsec{Sperrvermerk/Confidentiality clause} - -Optional.\\ - -Ingolstadt, \rule{0.3\textwidth}{0.4pt} \\ -\textcolor{white}{.}\qquad\qquad\qquad\qquad\quad \small (Date) \\ [1.3cm] - -(Signature) \\ -Firstname Lastname diff --git a/outlook.tex b/outlook.tex deleted file mode 100644 index 036270f..0000000 --- a/outlook.tex +++ /dev/null @@ -1,19 +0,0 @@ -% Kapitel 7 - Ausblick - -%\newgeometry{textheight=\paperheight, textwidth=\paperwidth} -%\begin{titlepage} -% %----THI-Bertrandt-logo-------------------------------------------------------- -% \begin{figure}[h!] -% \centering -% \includegraphics[width={\textwidth}]{titeltrenner/t7} -% \end{figure} -% %------------------------------------------------------------------------------ -%\end{titlepage} -%\restoregeometry -%%-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- - - -\section{Ausblick} - -\subsection{Einschränkungen} - diff --git a/titlepage.tex b/titlepage.tex index 044fd9a..929bcf4 100644 --- a/titlepage.tex +++ b/titlepage.tex @@ -35,7 +35,7 @@ Name and Surname: & \textbf{Philip Gaber} \\ [3em] Issued on: & 08.04.2021 \\ [1em] % issuing date - Submitted on: & xx.yy.zzzz \\ [3em] %date of hand in + Submitted on: & 01.08.2021 \\ [3em] %date of hand in First examiner: & Prof. Priv.-Doz. Dr. techn. Andreas Riener\\ [1em] Second examiner: & Prof. Dr. rer. nat. Franz Regensburger\\[3em]