Table 1.
Advantages and disadvantages of measures used to investigate human–robot interaction, together with example questions that can be best addressed with the respective measure; ERP, event related potential; PSP, postsynaptic potential; fMRI, functional magnetic resonance imaging; fNIRS, functional near infrared spectroscopy; TDS, transcranial doppler sonography; BF, blood flow.
| Method | Advantages | Disadvantages | Questions (examples) |
|---|---|---|---|
| Subjective measures | Explicit processes | Subjective measures | Traits |
| Likert scales | Inexpensive | Social acceptability bias | Attitudes |
| Implicit association | Easy-to-implement | Disrupts natural interaction | Acceptance |
| Interviews | No implicit processes | Judgments | |
| No performance measure | Likability | ||
| Classification/stereotyping | |||
| Performance measures | Objective measures | Disrupts natural interaction | Effectiveness/efficiency |
| Reaction times | Implicit/explicit processes | Needs specified goals | Competition |
| Error rates | Inexpensive | Indirect neural measure | Distraction |
| Easy-to-implement | Cognitive load | ||
| Social attention | |||
| Joint action | |||
| Search and rescue | |||
| Behavioral measures | Objective measures | Some discomfort | Free exploration (mobile) |
| Eye tracking | Implicit processes | Feeling of unnaturalness | Natural interaction (mobile) |
| Motion tracking | Relatively inexpensive | Indirect neural measure | Social attention (mobile) |
| Exploratory research | Not suitable for everyone | Social dynamics | |
| Non-disruptive | Preferences | ||
| Stress | |||
| Cognitive load | |||
| Movement kinematics | |||
| Physiological measures | Objective measures | Not specific in terms of cognitive processes | Stress |
| Heart rate | Implicit processes | Indirect neural measure | Alertness |
| Skin conductance | Relatively inexpensive | Low temporal resolution | Engagement |
| Respiratory rate | Non-disruptive | Cognitive load | |
| Electroencephalography | Objective measures | Some discomfort | Engagement |
| ERPs | Implicit processes | Feeling of unnaturalness | Social reward |
| (Time-) frequency | Relatively inexpensive | Timely to set-up | Task monitoring |
| Non-disruptive | Bound to laboratory setting | Error processing | |
| Direct neural measure (PSP) | Low spatial resolution | Entrainment | |
| High temporal resolution | Movement/other artifacts | Conflict processing | |
| Source localization possible | Social attention | ||
| Joint action | |||
| Violation of expectation | |||
| Neuroimaging | Objective measures | Some discomfort | Social reward |
| fMRI | Implicit processes | Feeling of unnaturalness | Social attention |
| fNIRS | Non-disruptive | Expensive | Bonding |
| TDS | Direct neural measure (BF) | Low temporal resolution | Empathy |
| High spatial resolution | Movement/other artifacts | Imitation | |
| Source localization possible | Anthropomorphism | ||
| Mind perception | |||