# Usability Testing of Mobile Applications:
## 4 Methodological Framework for Mobile Usability Testing
### Data Collection Techniques
#### 4.2.2 Participant Observation  
Participant observation is a qualitative research method [93] where the researcher deliberately participates in the activities of an individual or group that is the subject of the research [94]. There are four different types of participation [95]:  
* Passive occurs when the researcher is present but does not interact with people. At this level of participation, those being observed may not even be aware that they are being observed. By acting as a pure observer, a great deal of undisturbed information can be obtained [96].
* Moderate is when the observer is present at the scene of action. However, recognized as a researcher, the observer does not actively interact with those involved but may occasionally be asked to become involved. At this level of interaction, it is typical practice to use a structured observation framework. In some settings, moderate participation acts as a proxy until more active participation is possible.
* Active occurs when the researcher participates in almost everything that other people do with the aim of learning. In addition, a researcher proactively interacts with the participants (e.g., by talking to them and performing activities), thereby collecting all the necessary information.
* Complete is when the researcher is or becomes a member of the group that is being studied. To avoid disrupting normal activities, the role is usually hidden from the group [97].  
In general, the methodology of participant observation is practiced as a form of case study, attempting to describe a phenomenon comprehensively and exhaustively in terms of a formulated research problem [98].  
In usability studies, a typical setting for participant observation is passive. In this respect, a researcher acts as a moderator during a testing session. In addition, considering the presence of the moderator during the testing session, there are two types of usability testing approaches [99]:  
* Moderated, requiring the moderator to be present either in person or on camera. In an in-person-moderated usability test, a moderator asks a participant to complete a series of tasks while observing and taking notes. So, both roles communicate in real-time.
* Unmoderated, which does not require the presence of a moderator. Participants perform application testing at their own pace, usually guided by a set of prompts.  
It should be noted that both moderated and unmoderated sessions can be divided into local and remote studies. While the former involves the physical presence of a moderator, the latter can be conducted via the Internet or telephone. The unmoderated session is used when budget, time, and resources are limited [100]. In this line of thinking, such surveys are more efficient and less expensive; however, they are more suitable for larger pools of participants [101]. In addition, due to some participants' careless responding, the risk of the collection of unreliable data is also higher.  
Usability testing sessions are typically recorded, allowing retrospective analysis that provides first-hand insight into interactions and behaviors [102]. In particular, detailed analysis allows task performance to be reconstructed. By extracting specific numerical values from a video recording, it is possible to calculate metrics of observed usability attributes, including both effectiveness and efficiency. In addition, the video recordings serve as a valuable reference [103], allowing interested parties to observe first-hand how users navigate through interfaces, interpret content, and respond to various features, ultimately facilitating data-driven decisionmaking and continuous improvement in the mobile application development process [104].