Effects of Virtual Assistant Features on User Experience in Service Settings (AVir4Services)

Virtual Assistants as Agents of Change: Improving User Interaction and User Experience Outcomes in Service Delivery

This study examines how the characteristics and performance of virtual assistants influence user experience in service settings. Approximately 400 adults will interact with virtual assistants presented as avatars, chatbots, or voice assistants in simulated tourism, cultural, retail, or financial service situations.

Participants will be exposed to one or more experimental conditions that may differ in features such as communication style, language specificity, anthropomorphism, personalization, type of virtual assistant, level of immersion, or the presence of inaccurate responses or errors. After the interaction, participants will complete questionnaires about their perceptions, emotions, trust, satisfaction, acceptance of recommendations, and intention to use the virtual assistant.

During the experimental session, non-invasive methods may be used to measure visual attention and psychophysiological responses. These methods include eye tracking, electrodermal activity, electroencephalography, and automated facial expression analysis. Facial recordings will be used to analyze emotional expressions and will not be used to identify participants.

The study does not involve drugs, biological products, medical treatments, diagnostic procedures, or investigational medical devices. Its purpose is to improve scientific understanding of human interaction with artificial intelligence and virtual assistants in service environments.

Study Overview

• Status: Not yet recruiting
• Conditions: User Experience With Virtual Assistants in Service Settings
• Intervention / Treatment: Behavioral: High Anthropomorphism; Behavioral: Accurate Virtual Assistant Response; Behavioral: Inaccurate Virtual Assistant Response; Behavioral: Low Anthropomorphism

Detailed Description

Virtual assistants are artificial intelligence systems that enable users to interact with digital services via text, voice, or embodied avatars. Their use does not necessarily improve user experience because interaction outcomes may depend on the design and behavior of the virtual assistant, the service context, and the characteristics of the user.

The main objective of this study is to identify the factors that influence user interaction and user experience outcomes when people engage with virtual assistants in service settings. The study will examine characteristics such as the type of virtual assistant, communication style, language specificity, anthropomorphism, personalization, adaptability, appearance, voice, level of immersion, and the occurrence of inaccurate, erroneous, or unexpected responses.

Approximately 400 adults aged 18 years or older will participate in experimental sessions conducted primarily at the Consumer Behavior Research Laboratory (LICCO) of the University of Malaga. Participants will be recruited through the Online Recruitment System for Economic Experiments (ORSEE), university communication channels, social media, collaborating organizations, and other appropriate recruitment channels.

Participants will interact with or be exposed to virtual assistants developed or configured for the study. These may include avatars, chatbots, and voice assistants presented in two-dimensional or immersive three-dimensional environments. The experimental materials may also include edited images, audio, or video representing simulated interactions with virtual assistants in tourism, cultural, retail, financial, or other service contexts.

Depending on the specific experimental design, participants will be assigned to conditions that differ in one or more virtual assistant features or interaction outcomes. The study may compare different levels of anthropomorphism, communication styles, degrees of language specificity, personalization, assistant modality, immersion, or response accuracy. The final allocation procedures and experimental conditions will be defined before recruitment and documented in the study protocol and ClinicalTrials.gov record.

After the interaction, participants will complete questionnaires assessing variables such as perceived usefulness, enjoyment, symbolic benefits, trust, satisfaction, attitude toward the recommendation, acceptance of recommendations, perceived risk, privacy concerns, emotional response, and intention to use the virtual assistant. Relevant participant characteristics, including age, gender, personality, personal innovativeness, digital experience, and accessibility needs, may also be examined as explanatory or moderating variables.

Non-invasive consumer neuroscience and psychophysiological techniques may be used during the experimental session. Eye tracking will record gaze position, visual fixations, and eye movements. Electrodermal activity will be used to assess changes in physiological arousal. Electroencephalography will record electrical brain activity associated with cognitive and emotional processing. Automated facial expression analysis will code observable facial movements and emotional expressions. Facial recordings will not be used for biometric identification, authentication, or identity verification.

Participants will receive study information and provide informed consent before data collection. A safety screening questionnaire will be administered when required for the psychophysiological procedures. Data will be coded and stored separately from directly identifying information. Results will be reported only in aggregated, anonymized, or appropriately pseudonymized form.

The study is behavioral and non-therapeutic. It does not involve medication, biological samples, medical treatment, diagnosis, or evaluation of a medical device. The procedures are non-invasive, although participants may experience temporary tiredness or minor discomfort during the experimental session.

• Study Type: Interventional
• Enrollment (Estimated): 400
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Sebastián Molinillo Jiménez - Professor of Marketing, PhD; Phone Number: +34 952131265; Email: smolinillo@uma.es
• Study Contact Backup: Name: Francisco Rejón-Guardia, Associate professor of marketing, PhD; Phone Number: +34 952 13 12 68; Email: franrejon@uma.es

Study Locations

• Spain
  • Málaga, Spain, 29013
    • Consumer Behavior Research Laboratory (LICCO), University of Malaga
    • Contact: Sebastián Molinillo Jiménez Professor of Marketing and Principal Investigator, PhD; Phone Number: +34 952 13 12 65; Email: smolinillo@uma.es
    • Principal Investigator: Francisco Rejón-Guardia, PhD
    • Principal Investigator: Sebastián Molinillo Jiménez, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Adults aged 18 years or older.
• Able to understand the study information and provide informed consent.
• Sufficient proficiency in Spanish to understand the instructions and complete the study questionnaires.
• Able to interact with a computer-based virtual assistant and complete the experimental session.
• Willing to complete the study procedures, which may include questionnaires, eye tracking, electrodermal activity recording, electroencephalography, and facial expression recording.

Exclusion Criteria:

• Younger than 18 years.
• Unable to understand the study information or provide valid informed consent.
• Insufficient proficiency in Spanish to understand the instructions or complete the questionnaires.
• A visual, hearing, motor, or other condition that prevents completion of the specific experimental task and cannot be accommodated by the study procedures.
• A temporary health condition, discomfort, or technical incompatibility that, according to the study procedures, prevents safe or reliable completion of the experimental session.
• Previous participation in the same experimental protocol, when prior exposure could influence the study outcomes.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: High Anthropomorphism and Accurate Response; Participants will interact with a virtual assistant displaying a high level of anthropomorphic features. The virtual assistant will provide accurate and relevant responses during the service interaction.	Behavioral: High Anthropomorphism; The virtual assistant will display a comparatively high level of human-like visual, vocal, or conversational characteristics, as operationalized in the experimental protocol.; Behavioral: Accurate Virtual Assistant Response; The virtual assistant will provide accurate, relevant, and contextually appropriate information during the simulated service interaction.
Experimental: High Anthropomorphism and Inaccurate Response; Participants will interact with a virtual assistant displaying a high level of anthropomorphic features. During the service interaction, the virtual assistant will provide a predefined inaccurate or irrelevant response designed for the experiment.	Behavioral: High Anthropomorphism; The virtual assistant will display a comparatively high level of human-like visual, vocal, or conversational characteristics, as operationalized in the experimental protocol.; Behavioral: Inaccurate Virtual Assistant Response; The virtual assistant will provide a predefined inaccurate or contextually inappropriate response during the simulated service interaction. The error will be standardized across participants assigned to this condition and will not concern medical, safety-related, or other high-risk information.
Experimental: Low Anthropomorphism and Accurate Response; Participants will interact with a virtual assistant displaying a low level of anthropomorphic features. The virtual assistant will provide accurate and relevant responses during the service interaction.	Behavioral: Accurate Virtual Assistant Response; The virtual assistant will provide accurate, relevant, and contextually appropriate information during the simulated service interaction.; Behavioral: Low Anthropomorphism; The virtual assistant will display a comparatively low level of human-like visual, vocal, or conversational characteristics, as operationalized in the experimental protocol.
Experimental: Low Anthropomorphism and Inaccurate Response; Participants will interact with a virtual assistant displaying a low level of anthropomorphic features. During the service interaction, the virtual assistant will provide a predefined inaccurate or irrelevant response designed for the experiment.	Behavioral: Inaccurate Virtual Assistant Response; The virtual assistant will provide a predefined inaccurate or contextually inappropriate response during the simulated service interaction. The error will be standardized across participants assigned to this condition and will not concern medical, safety-related, or other high-risk information.; Behavioral: Low Anthropomorphism; The virtual assistant will display a comparatively low level of human-like visual, vocal, or conversational characteristics, as operationalized in the experimental protocol.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Trust in the Virtual Assistant	Trust in the virtual assistant will be assessed immediately after the interaction using a pre-specified multi-item questionnaire. Participants will rate each item on a 7-point Likert scale ranging from 1 (strongly disagree) to 7 (strongly agree). An overall trust score will be calculated as the mean of the completed items. Higher scores indicate greater trust in the virtual assistant.	Immediately after the virtual assistant interaction, during the same experimental session

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
User Satisfaction With the Virtual Assistant	User satisfaction will be assessed immediately after the interaction using a pre-specified multi-item questionnaire. Items will be rated on a 7-point Likert scale ranging from 1 (strongly disagree) to 7 (strongly agree). The satisfaction score will be calculated as the mean of the completed items. Higher scores indicate greater satisfaction.	Immediately after the virtual assistant interaction, during the same experimental session
Intention to Use the Virtual Assistant	Participants' intention to use a similar virtual assistant in the future will be assessed using a pre-specified multi-item questionnaire. Items will be rated on a 7-point Likert scale ranging from 1 (strongly disagree) to 7 (strongly agree). The overall score will be calculated as the mean of the completed items. Higher scores indicate greater intention to use the virtual assistant.	Immediately after the virtual assistant interaction, during the same experimental session
Acceptance of the Virtual Assistant Recommendation	Acceptance of the recommendation provided by the virtual assistant will be assessed after the interaction using a 7-point response scale. Higher scores indicate greater willingness to accept or follow the recommendation.	Immediately after the virtual assistant interaction, during the same experimental session
Electrodermal Activity During the Virtual Assistant Interaction	Electrodermal activity will be recorded continuously during the interaction. Skin conductance responses associated with the experimental stimuli will be derived from the recorded signal and compared across experimental conditions. Greater skin conductance responses indicate greater physiological arousal.	From the start to the end of the virtual assistant interaction, for up to 20 minutes.
Visual Attention During the Virtual Assistant Interaction	Visual attention will be measured using eye tracking. Pre-specified metrics will include fixation duration and number of fixations within defined areas of interest. The eye-tracking measures will be compared across experimental conditions.	Continuously during the virtual assistant interaction, over approximately 20 minutes.

Collaborators and Investigators

• Sponsor: University of Malaga

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): January 1, 2028
• Study Completion (Estimated): January 1, 2028

Study Registration Dates

• First Submitted: June 11, 2026
• First Submitted That Met QC Criteria: June 18, 2026
• First Posted (Actual): June 24, 2026

Study Record Updates

• Last Update Posted (Actual): June 24, 2026
• Last Update Submitted That Met QC Criteria: June 18, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Artificial Intelligence; Electroencephalography; Electrodermal Activity; Consumer Behavior; Eye Tracking; User Experience; Human-Computer Interaction; Facial Expression Analysis; Technology Acceptance; Virtual Assistants; Anthropomorphism
• Additional Relevant MeSH Terms: Behavior; Consumer Behavior
• Other Study ID Numbers: AVIR4SERVICES-EXP-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be made publicly available because the study includes potentially sensitive questionnaire, facial recording, eye-tracking, electrodermal activity, and electroencephalography data. Aggregated and fully anonymized results may be shared in scientific publications or institutional repositories, subject to ethical, legal, and data protection requirements.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No