## 5 Discussion  
The objective of predicting the use of an innovation is not an easy task. However, the stakes are high, since the aim is to accompany, as far as possible, the market launch of a technology that is likely to meet its public. To face this challenge, it is customary to work on the acceptability of a technological innovation or a service. The literature, mainly in human sciences, leads the authors to collect information from future users at three stages of the technology's development. A first measure, called acceptability, is carried out before the technology is used in order to identify the psychological dimensions considered a priori (i.e., before the user actually uses it) by the future user as essential in his intention to use the innovation in the future. After a development phase and several user tests, the system, theoretically in perfect working order, can be made available to future users to study its acceptance. The challenge is then to assess the way in which the latter are able to use the \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Dimension**} & \multirow{2}{*}{**D**} & \multirow{2}{*}{**M**} & \multicolumn{2}{c}{**Mean**} & \multicolumn{2}{c}{**SE**} & \multirow{2}{*}{**\(t\)**} & \multirow{2}{*}{**Cohen’s d**} \\  & & & & **Difference** & & & \\ \hline Performance & 0 & 4.50 & & & & & \\ Expectancy & 21 & 3.50 & & & & & \\ \hline Effort & 0 & 5.30 & & & & & \\ Expectancy & 21 & 5.35 & & & & & \\ \hline Social Influence & 0 & 4.04 & & & & & \\  & 21 & 3.60 & & & & & \\ \hline Facilitating & 0 & 4.88 & & & & & \\ Conditions & 21 & 4.10 & & & & & \\ \hline Behavioral & 0 & 5.30 & & & & & \\ Intention & 21 & 4.24 & & & & & \\ \hline \hline \end{tabular} Note.: * \(p<\)0.05, *** \(p<\) 0.001.  
\end{table} 
Table 6: Evolution of the average dimensions of the UTAUT between D0 and D + 21 SHERPAM project (\(t\)-Test Sample Pairs). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Performance** & **Effort** & **Social** & **Facilitating** & **Behavioral** \\  & **Expectancy** & **Expectancy** & **Influence** & **Conditions** & **Intention** \\ \hline Performance & — & & & & & \\ Expectancy & 0.740 *** & — & & & & \\ Effort Expectancy & 0.740 *** & — & & & & \\ Social Influence & & & & & & \\ Facilitating Conditions & 0.680 *** & 0.538 * & 0.622 ** & — & \\ Behavioral Intention & 0.520 * & 0.519 * & & & 0.731 *** & — \\ \hline \hline \end{tabular} Note.: * \(p<\)0.05, *** \(p<\) 0.005, *** \(p<\) 0.001.  
\end{table} 
Table 5: Correlation Matrix UTAUT dimensions—SHERPAM project D + 21.  
technology and to make good use of all its functions without any particular effort. During this first phase of interaction with the device, which can last as long as wanted, it is possible to study the evolution of the relationship with the technology. Thus, it is possible to verify whether the psychological dimensions identified in the acceptability measure remain good predictors of the intention to use the innovation. Finally, a third phase (appropriation phase) will make it possible to observe day after day how the user will use (or not use) the innovation to carry out his daily activities. It is then possible to see whether the innovation becomes an indispensable instrument in the ordinary life of its user. This research identified the reasons why it was crucial to have a fully functional device in the second phase (acceptance study). Indeed, it has been observed that a technology considered a priori (acceptability phase) as perfectly acceptable for which future users have expressed a certain intention of use (i.e., useful, adapted to their daily life), could lose in usefulness, in adaptation and consequently in intention of use, during a period of use characterized by dysfunctions and not by optimal functioning. Thus, the unreliability of a technology can lead participants to adopt a tester status over the course of malfunctions at the expense of the user status they were initially assigned.