Blockchain applications in education: a systematic literature review

Blockchain is one of the latest technologies attracting increasing attention from different actors in diverse fields, including the educational sector. The objective of this study is to offer an overview of the current state of the art related to blockchain in education that may serve as a reference for future initiatives in this field. For this, a systematic review of reference journals was carried out. Eleven databases were systematically searched and eligible papers that focused on blockchain in education that made significant contributions, and not only generic statements about the topic, were selected. As a result, 28 articles were analyzed. Lack of precision, and selection and analysis bias were then minimized by involving three researchers. The analysis of the selected papers provided invaluable insight and answered the research questions posed about the current state of the application of blockchain in education, about which of its characteristics can benefit this sector, and about the challenges that must be addressed. Blockchain may become a relevant technology in the educational field, and therefore many proofs of concept are being developed. However, there are still some relevant technological, regulatory and academic issues to be addressed to pave the way for the mainstream adoption of this technology

NFTs for the issuance and validation of academic information that complies with the GDPR

The issuance and verification of academic certificates face significant challenges in the digital era. The proliferation of counterfeit credentials and the lack of a reliable, universally accepted system for issuing and validating them pose critical issues in the educational domain. Certificates, traditionally issued by centralized educational institutions using their proprietary systems, pose challenges for straightforward verification, generating uncertainty about the credibility of academic achievements. In addition to diplomas issued by academic entities, it is now necessary in virtually all professional fields to stay updated and obtain accreditation for certain skills or experiences, which is a determining factor in securing or enhancing employment. Yet, there is no platform available to consistently demonstrate these capabilities and experiences. This article introduces a novel model for issuing and verifying academic information using non-fungible tokens (NFTs) supported by blockchain technologies, focused on compliance with the General Data Protection Regulation (GDPR). It describes a model that grants control to the data subject, enabling the management of information access while adhering to key GDPR principles. Simultaneously, it remains compatible with existing systems within organizations, and is flexible in certifying various types of academic information. The implications of this model are discussed, emphasizing the importance of addressing privacy in blockchain-based applications.Agencia Estatal de Investigación | Ref. TED2021-130828B-I0

Conversational Agents for depression screening: a systematic review

Objective: This work explores the advances in conversational agents aimed at the detection of mental health disorders, and specifically the screening of depression. The focus is put on those based on voice interaction, but other approaches are also tackled, such as text-based interaction or embodied avatars. Methods: PRISMA was selected as the systematic methodology for the analysis of existing literature, which was retrieved from Scopus, PubMed, IEEE Xplore, APA PsycINFO, Cochrane, and Web of Science. Relevant research addresses the detection of depression using conversational agents, and the selection criteria utilized include their effectiveness, usability, personalization, and psychometric properties. Results: Of the 993 references initially retrieved, 36 were finally included in our work. The analysis of these studies allowed us to identify 30 conversational agents that claim to detect depression, specifically or in combination with other disorders such as anxiety or stress disorders. As a general approach, screening was implemented in the conversational agents taking as a reference standardized or psychometrically validated clinical tests, which were also utilized as a golden standard for their validation. The implementation of questionnaires such as Patient Health Questionnaire or the Beck Depression Inventory, which are used in 65% of the articles analyzed, stand out. Conclusions: The usefulness of intelligent conversational agents allows screening to be administered to different types of profiles, such as patients (33% of relevant proposals) and caregivers (11%), although in many cases a target profile is not clearly of (66% of solutions analyzed). This study found 30 standalone conversational agents, but some proposals were explored that combine several approaches for a more enriching data acquisition. The interaction implemented in most relevant conversational agents is textbased, although the evolution is clearly towards voice integration, which in turns enhances their psychometric characteristics, as voice interaction is perceived as more natural and less invasive.Agencia Estatal de Investigación | Ref. PID2020-115137RB-I0

Episodix: a serious game to detect cognitive impairment in senior adults. A psychometric study

Introduction Assessment of episodic memory is traditionally used to evaluate potential cognitive impairments in senior adults. The present article discusses the capabilities of Episodix, a game to assess the aforementioned cognitive area, as a valid tool to discriminate among mild cognitive impairment (MCI), Alzheimer’s disease (AD) and healthy individuals (HC); that is, it studies the game’s psychometric validity study to assess cognitive impairment. Materials and Methods After a preliminary study, a new pilot study, statistically significant for the Galician population, was carried out from a cross-sectional sample of senior adults as target users. A total of 64 individuals (28 HC, 16 MCI, 20 AD) completed the experiment from an initial sample of 74. Participants were administered a collection of classical pen-and-paper tests and interacted with the games developed. A total of six machine learning classification techniques were applied and four relevant performance metrics were computed to assess the classification power of the tool according to participants’ cognitive status. Results According to the classification performance metrics computed, the best classification result is obtained using the Extra Trees Classifier (F1 = 0.97 and Cohen’s kappa coefficient = 0.97). Precision and recall values are also high, above 0.9 for all cognitive groups. Moreover, according to the standard interpretation of Cohen’s kappa index, classification is almost perfect (i.e., 0.81–1.00) for the complete dataset for all algorithms. Limitations Weaknesses (e.g., accessibility, sample size or speed of stimuli) detected during the preliminary study were addressed and solved. Nevertheless, additional research is needed to improve the resolution of the game for the identification of specific cognitive impairments, as well as to achieve a complete validation of the psychometric properties of the digital game. Conclusion Promising results obtained about psychometric validity of Episodix, represent a relevant step ahead towards the introduction of serious games and machine learning in regular clinical practice for detecting MCI or AD. However, more research is needed to explore the introduction of item response theory in this game and to obtain the required normative data for clinical validityThis research was supported by the University of VigoS

Implementing scripted conversations by means of smart assistants

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGSmart assistants are among the most popular technological devices at home. With a built-in voice-based user interface, they provide access to a broad portfolio of online services and information, and constitute the central element of state-of-the-art home automation systems. This work discusses the challenges addressed and the solutions adopted for the design and implementation of scripted conversations by means of off-the-shelf smart assistants. Scripted conversations play a fundamental role in many application fields, such as call center facilities, retail customer services, rapid prototyping, role-based training or the management of neuropsychiatric disorders. To illustrate this proposal, an actual implementation of the phone version of the Montreal cognitive assessment test as an Amazon's Alexa skill is described as a proof-of-concept.Agencia Estatal de Investigo | Ref. PID2020-115137RB-I00Ministerio de Ciencia, Innovación y Universidades | Ref. FPU19/0198

Design process and preliminary psychometric study of a video game to detect cognitive impairment in senior adults

Introduction Assessment of episodic memory has been traditionally used to evaluate potential cognitive impairments in senior adults. Typically, episodic memory evaluation is based on personal interviews and pen-and-paper tests. This article presents the design, development and a preliminary validation of a novel digital game to assess episodic memory intended to overcome the limitations of traditional methods, such as the cost of its administration, its intrusive character, the lack of early detection capabilities, the lack of ecological validity, the learning effect and the existence of confounding factors. Materials and Methods Our proposal is based on the gamification of the California Verbal Learning Test (CVLT) and it has been designed to comply with the psychometric characteristics of reliability and validity. Two qualitative focus groups and a first pilot experiment were carried out to validate the proposal. Results A more ecological, non-intrusive and better administrable tool to perform cognitive assessment was developed. Initial evidence from the focus groups and pilot experiment confirmed the developed game’s usability and offered promising results insofar its psychometric validity is concerned. Moreover, the potential of this game for the cognitive classification of senior adults was confirmed, and administration time is dramatically reduced with respect to pen-and-paper tests. Limitations Additional research is needed to improve the resolution of the game for the identification of specific cognitive impairments, as well as to achieve a complete validation of the psychometric properties of the digital game. Conclusion Initial evidence show that serious games can be used as an instrument to assess the cognitive status of senior adults, and even to predict the onset of mild cognitive impairments or Alzheimer’s diseaseThe present work has been funded by the government of Galicia (Xunta de Galicia, Spain) to cover the travel expenses to participants’ homes during the pilot experiment (Ref.: 2016/236)S

Oral vs. touch interaction for cognitive assessment: acceptance and perceived usability by senior adults

There is a digital divide between senior adults and the general population because of the disparity in access and usage of digital technologies, including the internet and modern devices, often stemming from factors like age, familiarity, and socioeconomic status. Yet, technology is increasingly penetrating the healthcare sector in areas such as screening, diagnosis, treatment, and follow-up. This study focuses on investigating how older adults perceive the introduction of new devices in the screening and diagnosis of cognitive impairment. For this, a perception study was carried out involving 25 senior adults, 16 women and 9 men, aged between 60 and 93 years, living in the Vigo area, Spain. First, the perception and acceptability of popular technological devices were evaluated by means of the technology acceptance model. Then, participants’ perceptions about the use of smart speakers and tablets for cognitive evaluation were analyzed, both before and after interacting with such devices. Finally, the perception of their caregivers about these tools was also studied. These instruments were found to be useful and enjoyable by older adults. More specifically, smart speakers were preferred by participants over traditional tests for detecting cognitive decline. Additionally, there were no significant differences in the perception of utility, ease of use, or enjoyment between tablets and smart speakers. Participants’ caregivers also reported an overall positive perception about the introduction of these new tools for cognitive assessment. In any case, the study provided evidence to support the introduction of both tablets and smart speakers to interact with older adults, and more specifically, as a means to facilitate the early detection and screening of cognitive decline.Agencia Española de Investigación | Ref. PID2020-115137RB-I00Xunta de Galicia | Ref. ED431B 2023/3

Assessment of validity and comparison of two spanish versions of the geriatric depression scale

Introduction: The Geriatric Depression Scale is an instrument used to identify depression in people of an older age. The original English version of this scale has been translated into Spanish (GDS-VE); two shorter versions of 5- (GDS-5) and 15-items (GDS-15) have been developed. Aim of the study: To assess the validity and compare the 5- and 15-item Spanish versions of the GDS among the Spanish population. Materials and methods: 573 Galicia residents aged >50 years participated in this study. The following instruments were applied: the 19-item Control, Autonomy, Self- Realization and Pleasure scale, the Subjective Memory Complaints Questionnaire, the Mini-Mental State Examination test, the GDS-5, and the GDS-15. Results: We found differences in total score between GDS-5 and GDS-15 regarding the variable sex. Internal reliability for GDS-5 and GDS-15 was 0.495 and 0.715, respectively. Sensitivity and specificity for GDS-5 – with a cut-off value of 1 – was 0.517 and 0.650, respectively; for GDS-15 – with a cut-off value of 3 points – sensitivity was 0.755 and specificity 0.668. GDS-5 has a ROC curve of 0.617 and GDS-15 of 0.764. Conclusion: GDS-15, and to a greater extent GDS-5, should be revised or even reformulated to improve their diagnostic usefulness by choosing higher discriminative ability items or even include new items with greater sensitivity that consider currently prevailing psychosocial factorsThis work was supported by Grant PID2020-115137RB-I00 funded by MCIN/AEI/10.13039/501100011033S

Cross-repository aggregation of educational resources

The proliferation of educational resource repositories promoted the development of aggregators to facilitate interoperability, that is, a unified access that would allow users to fetch a given resource independently of its origin. The CROERA system is a repository aggregator that provides access to educational resources independently of the classification taxonomy utilized in the hosting repository. For that, an automated classification algorithm is trained using the information extracted from the metadata of a collection of educational resources hosted in different repositories, which in turn depends on the classification taxonomy used in each case. Then, every resource will be automatically classified on demand independently of the original classification scheme. As a consequence, resources can be retrieved independently of the original taxonomy utilized using any taxonomy supported by the aggregator, and exploratory searches can be made without a previous taxonomy mapping. This approach overcomes one of the recurring problems in taxonomy mapping, namely the one-to-none matching situation. To evaluate the performance of this proposal two methods were applied. Resource classification in categories existing in all repositories was automatically evaluated, obtaining maximum performance values of 84% (F1 score), 87.8% (area under the receiver operator characteristic curve), 86% (area under the precision-recall curve) and 75.1% (Cohen's κ). In the case of resources not belonging to one of the common categories, human inspection was used as a reference to compute classification performance. In this case, maximum performance values obtained were respectively 69.8%, 73.8%, 75% and 54.3%. These results demonstrate the potential of this approach as a tool to facilitate resource classification, for example to provide a preliminary classification that would require just minor corrections from human classifiers.Xunta de Galicia | Ref. R2014/034 (RedPlir)Xunta de Galicia | Ref. R2014/029 (TELGalicia