The best method of personality assessment for knowing the popularity of a person in a group is- 

Personality assessment refers to the techniques used to measure an individual's character traits, behaviors, and social interactions. When trying to evaluate a person's popularity within a group, it is essential to choose a method that focuses on social relationships and preferences among group members.

Key Points

• Sociometry is the most suitable method for assessing popularity in a group. This technique, developed by J.L. Moreno, involves asking individuals to select people with whom they would prefer to work, sit, or socialize.
• The data collected reveals patterns of attraction, acceptance, and rejection within the group. Through sociometric charts and matrices, one can identify individuals who receive the highest number of positive choices, indicating their popularity.
• This method is particularly useful in classrooms and team environments where group dynamics are important.
• It goes beyond surface behavior and captures genuine peer preferences.

Hint

•  Observation is useful for identifying behavioral patterns but does not directly reveal how popular a person is unless supplemented with other tools. It may reflect confidence or leadership but may miss internal group choices.
• Questionnaire collects information about personality traits or self-perception but does not provide insights into how a group perceives a particular member’s popularity.
• Interview allows in-depth exploration of an individual's personality but is based on verbal responses and lacks group-level data to measure comparative popularity among peers.

Hence, the correct answer is sociometry.