# AgriEnt: A Knowledge-Based Web Platform for Managing Insect Pests of Field Crops
## 4 Case Study: Diagnosing the Insect Pest Affecting a Crop
### User-Centered Evaluation  
When a new technology is introduced, it is necessary to study how users come to accept and use it. From this perspective, AgriEnt was evaluated by using the TAM (technology acceptance model) [43] which is a theoretical model that explains perceived usefulness and usage intentions. Specifically, the case study performed in this work aimed to measure the perceived usefulness, perceived ease of use, attitude, and behavioral intention to use, of the AgriEnt platform. These aspects were measured at four months postimplementation (February-May 2019). Once farmers involved in this case study used the AgriEnt Web application for insect pests' diagnosis purposes, they were asked a set of questions focused on measuring their perceptions and experiences using the platform through the aspects mentioned in the previous paragraph. The questions for perceived usefulness, perceived ease of use, and behavioral intention to use were taken from the updated TAM model known as TAM2 [43]. Meanwhile, the questions for attitude were taken and slightly adapted from [44]. The questionnaire relied on a 7-point Likert scale ranging from 1 (Strongly disagree) to 7 (Strongly agree) which allowed farmers to express how much they agree or disagree with the aspects under evaluation. A complete description of the questionnaire used in this case study is presented in Appendix A. All 20 farmers involved in this work completed the survey through the AgriEnt Web application. Then, measurement validity was evaluated in terms of reliability. Specifically, the data collected from this questionnaire were analyzed using [PERSON]'s alpha. The test results of this analysis are presented in Table 6.  
In the first column of Table 6, the name of the constructs and the corresponding questions are listed (see Appendix A for abbreviations). The second and third columns present the mean and standard deviation respectively, while in the fourth column the values of [PERSON]'s alpha are shown. From the results in Table 6, we can conclude that all measurement scales have high reliability since all of them fulfill the commonly used [PERSON]'s alpha threshold value for acceptable reliability (0.80).  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Construct** & **Mean** & **S.D.** & **Cronbach’s Alpha** \\ \hline Perceived usefulness (PU) & & & 0.868 \\ PU1 & 5.60 & 0.82 & \\ PU2 & 6.05 & 0.75 & \\ PU3 & 5.85 & 0.48 & \\ PU4 & 5.95 & 0.60 & \\ Perceived ease of use (PEOU) & & & 0.806 \\ PEOU1 & 5.60 & 0.82 & \\ PEOU1 & 5.75 & 0.71 & \\ PEOU1 & 5.80 & 0.61 & \\ PEOU1 & 5.75 & 0.55 & \\ Attitude (ATT) & & & 0.864 \\ ATT1 & 5.60 & 0.82 & \\ ATT2 & 6.05 & 0.75 & \\ ATT3 & 5.80 & 0.61 & \\ Behavioral intention to use (ITU) & & & 0.829 \\ ITU1 & 5.6 & 0.82 & \\ ITU2 & 6.05 & 0.75 & \\ \hline \hline \end{tabular}
\end{table}
Table 6: Analysis of measurement reliability: descriptive statistics and Cronbach’s alphas.  
Figure 4 depicts the proposed model, which is based on TAM, as well as a summary presentation of the results. A regression analysis was performed to test this model. As can be noted from Figure 3, the results obtained support most of the causal paths postulated by the TAM theoretical model. Specifically, perceived ease of use (PEOU) significantly affects perceived usefulness (PU) with a value of 0.839. However, contrary to what the TAM model suggests, PEOU was found to have no significant effect on attitude (ATT). The effects of PU were significant in ATT. Finally, consistent with the TAM model, ATT was found to have a significant effect on the intention to use (ITU) the AgriEnt platform with a value of 0.678. This last fact suggests that attitude in farmers' acceptance of AgriEnt is relatively important and contributes to predicting the intention to use.