# MobiDabet: Mobile Telemonitoring System for Patients with Type 2 Diabetes Mellitus (T2 DM)
## 4 Preliminary Usability Assessment of the Proposed System
### Description of the Preliminary Usability Assessment of the System Based on a Field Study
#### 4.1.2 Description of Usability Instruments  
The instruments used to measure the usability aspects (efficiency, effectiveness, satisfaction, presentation, content, and navigation) of our system are described below.  
**Description of Instrument 1.**  
Instrument 1 is a specific task list test for each of the users who were interacting with different system services. This test is divided into two sections, the first section allows to measure the effectiveness in the completeness of tasks, and the second allows to measure the efficiency in the time of tasks performed in the system.  
For patient users, the effectiveness and efficiency in health education, nutrition, glucose registration, and laboratory results services were evaluated, this questionnaire consisted of completing 14 tasks corresponding to each service and recording the time spent to perform each one.  
For general physician/family doctor users, the effectiveness and efficiency in the clinical history, laboratory results, and nutrition services were evaluated. This questionnaire consisted of completing 18 tasks corresponding to each service and recording the time spent to perform each one.  
Regarding the nutritionist users, the effectiveness and efficiency in the services of clinical history, laboratory results, nutrition, load pattern, and menus, were evaluated. This questionnaire consisted of completing 17 tasks corresponding to each service and recording the time spent to perform each one.  
**Description of Instrument 2.**  
We used the QUIS 7.0 [17] as our Instrument 2 to measure user interaction satisfaction. This questionnaire consists of thirty-two questions grouped into six categories:  
* Global reaction to the system: Includes questions to know the user's perception regarding utility, flexibility, facility, among other aspects.
* Screen: Includes questions aimed at evaluating screen characteristics such as typography, design, distribution, and sequence.
* System terminology and information: Evaluates whether the terms applied help users to reach their goals and if there is consistency in the positioning and content of the messages.
* Learning: Collects information about user facility in learning to use the software.
* System capabilities: It allows identifying the performance and recovery capacity of the system before errors are caused by the user.
* Ease of use and user interface: Evaluates general aspects of the software interface design.  
In this questionnaire, users must answer the questions using a scale of points from 0 to 9. Scores from 0 to 3 are considered as an unacceptable level, from 4 to 6 an acceptable level, and from 7 to 9 a satisfactory level.  
**Description of Instrument 3.**  
Our Instrument 3 is an adaptation of the questionnaire for the quality of a product in use and web system, introduced previously [18], which consists of 25 questions related to three characteristics included in a web information system: content, navigation, and presentation. This Instrument is answered through a Likert-5 scale, comprising 5 options: (1) Strongly disagree, (2) Disagree, (3) Neutral, (4) Agree, and (5) Strongly agree. In the content characteristic, the questionnaire measures aspects such as consistency, conciseness, interpretability, updated, significant, and adaptation to the user's needs. Concerning the presentation characteristic, the questionnaire measures: uniformity and color, uniformity of distribution, consistency in links and controls, compatibility with browsers,readability of information, setting default values in the user interface, data validation, privacy of information, subsequent modification of data entered, ease of recognition of user interface components, cancellation or undo actions, and adaptation to user needs. On the other hand, in the navigation feature, the following features are evaluated within the questionnaire: internal search availability, home page with main options, location of primary navigation menus in the left panel, and significant links.