Human factors are critical in the design and development of various products, but wideness and unclarity of different aspects of these factors make it difficult to extract demands of users. Studying emotional aspects of users' behavior in interaction with products, as well as interviewing them, is considered as an efficient tool in extracting design demands. This study aims to integrate the application of task analysis and the measuring of emotional aspects to determine the users’ emotional states in the different stages; and therefore extract the user satisfaction criteria.

This research has a descriptive/ exploratory approach. In this practical study, the use of two everyday tools for chopping onions is analyzed. 20 users of these tools were non-randomly selected to participate in the test and interview. Users performed the task with each tool, and the process was recorded by a camera. After performing the task, subjects completed self-assessment questionnaire and then, an interview was conducted about their experience of the tools usage. Parametric t test was used to evaluate results of the questionnaire and compare averages.

Findings of the emotional questionnaire showed that the emotional states of people in different stages of task are significantly different from each other. The determined emotional states, showed the weaknesses and the advantages of the tools studied. By analyzing videos, interviews and surveys, users' demands were extracted. The extracted features were categorized based on the work steps.

Using this method can reveal precise details of users’ needs concerning product category, which can be used as a suitable tool for designers and researchers in the field of user experience.