Fig 1.
Flow diagram of the GT process.
The process consists of three phases: Sampling, Data Collection, and Data Analysis. Selection of volunteers is performed during the Sampling phase. Relevant information about the volunteers is acquired during the Data Collection phase. The information is classified and codified during the Data analysis phase. The Sampling–Data Collection–Data Analysis cycle repeats until no more information is gained in the process (saturation). The activities of each phase changes as the cycle evolves. See the text for more details.
Fig 2.
Elements obtained through coding and its relationship.
The researcher transcribes fragments of the sessions with the volunteers during the open coding process. From these transcripts, the researcher distills a set of data units, called RDUs. These units are mutually exclusive, and cover the whole conceptual model. Similar RDUs are summarized in “concepts” (CON). Finally these “concepts” are clustered in categories (CAT) based on the cause of the error or problem associated to each concept.
Fig 3.
Number of new and repeated RDUs.
The figure shows the evolution of the number of new (in red) and repeated RDUs (in blue) as new volunteers were added to the model. The green line represents the saturation level.
Table 1.
RDUs, concepts and categories.
Fig 4.
Visualization of the conceptual model.
The figure shows the 30 identified categories and a corresponding score from 1 (the category is not satisfied) to 5 (the category is fully satisfied). Left column shows the categories related to the user, and the right column shows the categories related to the medical device. The categories are also grouped vertically according to the area they belong.