# We Do Not Anthropomorphize a Robot Based Only on Its Cover: Context Matters too!
## 5 Limits
### The Measure of Anthropomorphism and Its Limits
#### 5.2.1 Questionnaires and Implicit Measures  
Different questionnaires (all based on Likert scales) are used in the literature to measure anthropomorphism from the user's perspective. A review of the literature shows that authors have used questionnaires that focused on anthropomorphism in the broad sense (e.g., the Godspeed questionnaire [6], individual differences in anthropomorphism [44],which correspond to _weak_ anthropomorphism), whereas others focus specifically on cognitive anthropomorphism (e.g., the attribution of mental states questionnaire [97], which corresponds to strong anthropomorphism). The Godspeed questionnaire [6] is one of the most frequently used questionnaires [79; 140; 147; 230] and consists of 5 items scored on a 5-point Likert scale. It assesses five domains: anthropomorphism, animation/illusion of life, appreciably, perceived intelligence, and perceived safety. Another questionnaire often used assesses the attribution of mental states to agents presented as pictures to measure anthropomorphism [77] and consists of 25 questions that are divided into 5 dimensions: perceptual, emotional, intentional, imaginative, and epistemic. As an example, for the perceptual attribution assessment, participants answer the question, \"Do you think he can feel heat or cold?\". Nevertheless, the questionnaires measuring anthropomorphism vary widely since many other questionnaires have also been used, e.g., the individual differences in anthropomorphism [44]. The individual differences in anthropomorphism questionnaire consists of 30 items, scored on a 10-point Likert scale. They assess the attribution of anthropomorphic traits, e.g., intentions, emotions, free will, mind, and of non-anthropomorphic traits, e.g., \"durable, \"active\", and the robot interactive experiences questionnaire [231]. The robot interactive experiences questionnaire includes 8 items scored on a 7-point Likert scale. They assess the individual's attitude in situations of engagement and social interactions with a robot. Moreover, the validity of verbal (explicit) measures for assessing mental state attribution is questioned [16].  
In the field of human-robot interactions, the importance of implicit measures deserves to be emphasized: the results obtained with these measures are not necessarily similar to those obtained with explicit measures, such as questionnaires [22; 117; 144]. Verbal and nonverbal measures of attribution of mental states to a robot can lead to divergent results [16; 217]. Indeed, children may show similar behavior when interacting with a robot and with a human, while they attribute fewer mental states to the robot based on their responses to questionnaires [232]. For this reason, indirect (implicit) and more objective methods have been used to assess the tendency toward anthropomorphism, including relying on social dilemma-type paradigms (such as the mini-dictator game and a resource-sharing task [40]; a moral dilemma [65]; or the ultimatum game [228]) that identify, for example, giving behaviors. Nonverbal paradigms have also been used to implicitly assess the attribution of mental states to the robot (e.g., the gaze anticipation paradigm, [16]; or the implicit association task, [217]). Further studies are needed to determine which type of measure--explicit or implicit--better reflects mental state attributions to robots [16]. Until this debate is resolved, studies should include both types of anthropomorphism measurements.  
Generally, the majority of studies focused on anthropomorphic robot designs (either by their appearance or by the way they are presented to the user) aim to assess its impact on subjective measures, such as the robot's perceived intelligence, acceptance, or realism [73], and pay little attention to the impact on more objective measures (such as performance [79]). While the major advantage of questionnaires is their ease of administration [228], they have some limitations.