# Commonly Used External TAM Variables in e-Learning, Agriculture and Virtual Reality Applications
## 3 Method
### Phase 3--Strength of the Relationships and Relationship Matrix  
It is a common interest among academics who develop TAM extensions, to comprehend the relationships existing between external variables and TAM's two main determinants PU and PEOU [6]. For this reason, two QFD matrices, one for each of the TAM's two primary constructs, were constructed and considering that in the TAM, PEOU is also a determinant of PU [7], we included the construct PEOU within the PU matrix to analyze its effect. One of the most commonly reported statistical indexes in TAM studies is the Path coefficient (\(\beta\)). Path coefficients indicate not only the strength of the relationships but also the causal effect of the common external factors (independent variables) on the dependent variables (PU and PEOU) and the effect of PEOU on PU as depicted in Figure 5[126]. \begin{table}
\begin{tabular}{c c} \hline \hline
**External Variables** & **Included in the Proposed Model of Studies** \\ \hline Anxiety & 7 \\ Content quality & 11 \\ Experience & 7 \\ Facilitating conditions & 10 \\ Individual innovativeness & 8 \\ Perceived enjoyment & 8 \\ Self-efficacy & 30 \\ Service/System quality & 7 \\ Social norm & 24 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Most commonly used external variables in TAM applications. \begin{table}
\begin{tabular}{l c} \hline \hline
**External Variable** & **Definition** \\ \hline Anxiety (ANX) & “An individual’s apprehension, or even fear when she/he is faced with the possibility of using computers.” [23; 110]. \\ Content quality (CQ) & Extent to which the information fits user needs [111] in terms of information organization, relevance and actuality [112], availability of support materials, and accuracy of the terminology [70]. \\ Experience (EXP) & Past interactions or exposure of an individual to a system and the accumulated knowledge gained by usage [113; 114; 115]. \\ Facilitating conditions (FC) & Users’ beliefs about the existence of technical and organizational resources and infrastructure to facilitate the use of technology [116]. \\ Individual innovativeness (II) & Individual’s disposition towards adopting any new technology before others [117; 118]. \\ Perceived enjoyment (PE) & Refers to how pleasant and entertaining is the use of the innovation, separately from any performance consequence that can be deducted from system usage [44; 110; 119]. \\ Self-efficacy (SE) & Over’s confidence in his/her capabilities to perform a task, achieve a specific goal, or produce the desired outcomes by properly using an innovative system or device [120; 121; 122]. \\ System quality (SQ) & Technical achievements, the accuracy, and efficiency of the system [123]. \\ Social norm (SN) & The extent to which the ideas coming from others may foster or discourage the use of technology [22; 124; 125]. \begin{table}
\begin{tabular}{c c} \hline \hline
**External Variables** & **Included in the Proposed Model of Studies** \\ \hline Anxiety & 7 \\ Content quality & 11 \\ Experience & 7 \\ Facilitating conditions & 10 \\ Individual innovativeness & 8 \\ Perceived enjoyment & 8 \\ Self-efficacy & 30 \\ Service/System quality & 7 \\ Social norm & 24 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Definitions of the “How’s”. However, some of the analyzed studies did not report this information directly, and in some others, the independent and dependent variables were not directly linked. The number of works grouped in each category reporting the path coefficients is shown in Table 4. In addition, Table 4 specifies the quantity of studies reporting the relationship for each one of the TAM determinants, PU and PEOU. Deviating from the conventional QFD matrix in which the importance of customer requirements is assigned using a Likert scale of points 1 to 5, the degree of importance of our study's research problematics was determined based on the number of studies belonging to each category and reporting path coefficients.