=Paper= {{Paper |id=Vol-2778/paper2 |storemode=property |title=User-Centered Design for Knowledge Imbalance Analysis: A Case Study of ProWD |pdfUrl=https://ceur-ws.org/Vol-2778/paper2.pdf |volume=Vol-2778 |authors=Nadyah Hani Ramadhana,Fariz Darari,Panca O. Hadi Putra,Werner Nutt,Simon Razniewski,Refo Ilmiya Akbar |dblpUrl=https://dblp.org/rec/conf/semweb/RamadhanaDPNRA20 }} ==User-Centered Design for Knowledge Imbalance Analysis: A Case Study of ProWD== https://ceur-ws.org/Vol-2778/paper2.pdf
         User-Centered Design for Knowledge Imbalance
               Analysis: A Case Study of ProWD

     Nadyah Hani Ramadhana1 , Fariz Darari1,4 , Panca O. Hadi Putra1 , Werner Nutt2 ,
                    Simon Razniewski3 , and Refo Ilmiya Akbar1
             1
                 Faculty of Computer Science, Universitas Indonesia, Depok, Indonesia
                      2
                        Free University of Bozen-Bolzano, Bozen-Bolzano, Italy
                   3
                       Max Planck Institute for Informatics, Saarbrücken, Germany
                     4
                        Tokopedia-UI AI Center of Excellence, Jakarta, Indonesia


         Abstract. Not all topics within a knowledge graph are represented at the same
         depth, which might lead to biased conclusions derived from the graph. Tools have
         been created in an effort to highlight knowledge imbalances, one of which is
         ProWD, built to analyze imbalances in the Wikidata knowledge graph. However,
         as often found, the usability aspect of Semantic Web tools is commonly over-
         looked, resulting in their limited acceptance. In this paper, we utilize the stan-
         dard approach to improve usability, i.e., the User-Centered Design (UCD), for
         ProWD. We employ the full range of steps of UCD to improve the user expe-
         rience of ProWD despite the complex nature of knowledge graph concepts un-
         derlying ProWD. The result of the ProWD redesign is then evaluated using the
         System Usability Scale (SUS) and User Experience Questionnaire (UEQ) scores,
         as well as the task success rate and completion time, suggesting that the overall
         usability of ProWD has successfully improved.

         Keywords: Knowledge Imbalance · Wikidata · User-Centered Design


1      Introduction
The increasing utilization of knowledge graphs (KGs) makes it necessary to ensure
their quality. One of the most popular KGs is Wikidata, which is part of the free-content
Wikimedia family with its main goal to collaboratively collect structured data to be used
by anyone [15]. In a commercial context, Wikidata is used by companies like Ama-
zon5 and Google.6 In terms of quantity, there are over 1.1 billion statements describing
88 million items7 on Wikidata about various topics, ranging from humans and cats to
movies and museums. Given such a vast quantity, the question arises as to whether
all topics within Wikidata (or any KG, in general) are represented in a well-balanced
manner. This question is particularly important as failing to notice the existence of im-
balances in a KG might lead to misleading conclusions derived from the KG.
 5
   https://www.wired.com/story/inside-the-alexa-friendly-world-of-wikidata/
 6
   https://ahrefs.com/blog/google-knowledge-graph/
 7
   https://wikidata-todo.toolforge.org/stats.php

     Copyright � c 2020 for this paper by its authors. Use permitted under Creative Commons Li-
     cense Attribution 4.0 International (CC BY 4.0).


                                                14
User-Centered Design for Knowledge Imbalance Analysis: A Case Study of ProWD


 Related Work. In terms of data quality, the problem of analyzing the existence of knowl-
 edge imbalances touches mainly two aspects: completeness and coverage. Data com-
 pleteness concerns the degree to which all necessary information is provided, whereas
 data coverage refers to the level of detail of the information stored [17]. Knowledge
 imbalances occur whenever there are disparities of completeness as well as coverage
 between different topics in a KG.
     In the context of Wikidata, identifying and measuring knowledge imbalances are
 deemed to be an important step to advance knowledge equity in Wikidata [18]. A num-
 ber of initiatives have been undertaken to address knowledge imbalances in Wikidata.
 Denelezh is a tool developed to track the gender gap in Wikidata [7]. Via Denelezh, one
 may, for example, compare the number of male vs. female humans in Wikidata. In [1],
 a map-based visualization shows which locations worldwide have how many Wikidata
 items. Through the visualization, one might observe that there is a stark difference be-
 tween the number of Wikidata items located in North America vs. South America. Re-
 coin [2] measures the different levels of completeness among Wikidata items, ranging
 from very basic information to very detailed information.

 ProWD. Let us now draw attention to ProWD. ProWD is a framework to measure
 knowledge imbalances in Wikidata [16]. ProWD generalizes the above initiatives in
 the sense that ProWD can be leveraged to any domain instead of only the gender or
 geographical domain. The framework measures knowledge imbalances based on Class-
 Facet-Attribute (CFA) profiles. A class groups similar items, which might comprise
 multiple facets, thus allowing attribute completeness to be compared. For example, via
 ProWD one may compare the completeness of the attribute “date of birth” and “edu-
 cated at” between US inventors vs. Nigerian inventors, as illustrated in Fig. 1. In the
 figure, we observe that 95.65% and 49.07% US inventors have the “date of birth” and
 “educated at” information, respectively. On the other hand, 100% (i.e., all) and 83.33%
 Nigerian inventors have the “date of birth” and “educated at” information, respectively.
 Moreover, the absolute number of Nigerian inventors seems to be far less than that of
 US inventors. The ProWD tool is available at http://prowd.id:3333/.8

 Problem and Contribution. While ProWD indeed offers basic functionalities in identi-
 fying knowledge imbalances in Wikidata, little concern was given to the extent to which
 the ProWD tool can be used by its users to achieve their goals with effectiveness and
 satisfaction. This very notion of usability [10] is nevertheless commonly overlooked by
 KG application developers [4]. The novelty and intricacies of the KG concepts under-
 lying ProWD as well as the fact that ProWD was developed without any rigorous user
 analysis and testing, raise questions about its usability.
     In an effort to improve the usability of ProWD, one could prioritize the (potential)
 users in such a way that their particular needs can be accommodated more accurately.
 A process commonly used in the development of a product, putting the user experience
 and usability front and center, is the User-Centered Design (UCD). The UCD approach
 is widely investigated and utilized in academia and industry [12]. Adapting and imple-
 menting the UCD approach towards the development of ProWD is challenging for two
  8
      A demo video of the tool is also available at https://youtu.be/3jcXXx1uQU4.


                                                15
User-Centered Design for Knowledge Imbalance Analysis: A Case Study of ProWD




 Fig. 1. Comparison of the completeness of attributes between US inventors and Nigerian inven-
 tors on the original ProWD (Source: http://prowd.id:3333/#/profile/compare/123)


 reasons: (i) knowledge graphs are a new abstract concept, and (ii) the imbalance analy-
 sis of such a graph is even more abstract. With that being said, this paper contributes to
 the adaptation and implementation of the UCD approach in the KG setting to improve
 ProWD, a knowledge imbalance analysis tool.

 Paper Structure. The rest of the paper is outlined as follows. Sec. 2 provides a brief
 background of the research. The next four sections correspond to adapting the steps
 of UCD in improving the usability of ProWD: understanding ProWD’s context of use
 (Sec. 3), specifying ProWD user requirements (Sec. 4), redesigning ProWD (Sec. 5),
 and evaluating the redesigned ProWD (Sec. 6). Sec. 7 concludes our paper.

 2   Background

 Knowledge Graphs. A knowledge graph (KG) describes real-world entities and their
 relationships [3]. Resource Description Framework (RDF) is the standard data model
 by W3C for KGs [8]. For example, the statement Bob is a human can be modeled in
 RDF as a Subject-Predicate-Object triple (Bob, is, human). To query RDF data,
 one could use SPARQL, which provides rich query constructs, enabling the creation
 of complex SPARQL queries [8]. Wikidata is an open, cross-domain KG, providing
 structured data to anyone [15]. Wikidata provides RDF support which can be queried
 via its SPARQL endpoint.


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User-Centered Design for Knowledge Imbalance Analysis: A Case Study of ProWD


 User-Centered Design. UCD is a design process comprising four activities: (i) under-
 stand the context of use, (ii) specify user requirements, (iii) design alternative solu-
 tions, and (iv) evaluate against requirements [10]. UCD prioritizes user needs in the
 design and development process of a product. To evaluate a product in UCD, several
 usability metrics can be used, such as the success rate and time on task, as well as
 questionnaire-based metrics like the System Usability Scale (SUS) [14] and User Expe-
 rience Questionnaire (UEQ) [13]. The SUS measures the overall usability of a system,
 while the UEQ measures six scales of a product: (i) attractiveness, (ii) perspicuity, (iii)
 efficiency, (iv) dependability, (v) stimulation, and (vi) novelty.

 3   Understanding ProWD’s Context of Use

 To improve upon an existing application, one must understand the context of use of the
 application. From this section onwards, we refer to the original version of ProWD [16]
 as ProWD-V1 and the redesigned version of ProWD resulting from our research
 as ProWD-V2. ProWD was developed in a technology-driven manner and was made to
 shed light on imbalances that might exist within Wikidata. This technology-driven de-
 velopment led to the application being less user-friendly as the users were not involved
 in the development process.
     The creators of ProWD wishes to advance ProWD to be utilized more widely by
 users outside the Wikimedia community (WM Community). The creators observed and
 concluded that the main challenges of ProWD are: (i) the abstract notion of the Wikidata
 knowledge graph and its imbalance analysis, and (ii) the lack of an existing ProWD user
 base. To tackle those challenges, one needs to be able to convey properly such abstract
 concepts, and to analyze (and accommodate) the generic and specific user requirements
 of ProWD.
     To confirm this, we initiated a meeting with representatives of the WM Commu-
 nity of Jakarta (the capital of Indonesia) to gather feedback and insights about their
 expectations towards ProWD. The WM Community of Jakarta is considered to be rep-
 resentative of the Wikidata Community as they are experienced with Wikidata and are
 interested in the issue of imbalance and the potential of ProWD as a tool. The meeting
 uncovered several potential usability issues. The target users identified were as follows:
 (i) data journalists, as Wikidata could become a data source for news topics, (ii) data
 professionals, as Wikidata might enrich their data analysis, and (iii) AI researchers, as
 Wikidata could be utilized for training data to build AI models.

 4   Specifying ProWD User Requirements

 Having identified the potential user base, we wanted to collect their requirements. To
 gather those requirements, the targeted users participated in usability testing and are
 interviewed. As ProWD-V1 has already existed, a heuristic evaluation is done to gather
 the requirements of how the application can be improved [6]. Hence the process of
 specifying the requirements is two-fold: (i) heuristic evaluation to gather generic user
 requirements, and (ii) evaluation based on specific requirements from the appropriately
 chosen test-participants from the defined user base.


                                            17
User-Centered Design for Knowledge Imbalance Analysis: A Case Study of ProWD




                       Fig. 2. Compare two facet values feature on ProWD-V1

 4.1     Heuristic Evaluation

 The heuristic evaluation using Nielsen’s ten usability heuristics [11] shows how the
 use of technical terms with a lack of further documentation in ProWD-V1, hence con-
 fusing the users. An example is the term “Class-Facet-Attribute” in the landing page
 of ProWD-V1, which confuses the users as there is no further information on what it
 exactly means and how it ties to the purpose of the application.
     Within the “see full profile”, “compare two facet values”, and “multi-dimensional
 analysis”, the users are burdened with a large cognitive load as they need to keep
 scrolling back and forth to look back within the same page, which is against the “Recog-
 nition rather than recall” heuristic. ProWD-V1 is lacking in providing alerts about the
 status of the system, for example, whether a page is loading or an error occurs for the
 page. Fig. 2 illustrates such usability issues in ProWD-V1.

 4.2     User Research and Testing

 Selection of Test-Participants. The test-participants were chosen based on the context
 of use, namely, WM community members and potential Wikidata users. A total of five
 users from each distinct user group were selected. In selecting the test-participants, the
 method used was purposive sampling.9 To lessen the bias as much as possible, we chose
 test-participants who would be critical towards systems such as ProWD based on their
 experience, occupation, and their sensitivity and interest towards knowledge, culture,
 data, and education.
      The selection process led us to have five WM community members and five poten-
 tial Wikidata users comprising data analysts, journalists, and teachers/researchers: (i)
 the WM community members are all from Jakarta and are those in high-profile posi-
 tions which presumably would have valuable and critical feedback for ProWD as they
 have the biggest drive for ProWD’s purpose; (ii) since ProWD’s functionality is quite
  9
      That is, intentional selection of informants based on their ability to elucidate a specific theme,
      concept, or phenomenon.


                                                   18
User-Centered Design for Knowledge Imbalance Analysis: A Case Study of ProWD


 similar to that of a dashboard, data analysts would be familiar with the kind of task
 that ProWD supports and would be able to give valuable feedback; (iii) lastly, the cho-
 sen journalist and teachers are people who are highly sensitive towards social/cultural
 issues, e.g., gender bias.

 User Research and Persona. To create a clear and constant reference to the users, a per-
 sona can be created [9]. The test-participants were interviewed to discover more about
 their personality, needs, and expectations using a semi-structured interview. The inter-
 view reveals that 100% of the test-participants have previously encountered a form of
 imbalance in general knowledge, while 90% state that more information on the imbal-
 ances would be insightful for their work. These confirm that ProWD has a potential in
 helping these users. From the interview, we also observe that users have a varying de-
 gree of Wikidata proficiency, so we divide the target users into two main personas. The
 first persona is the WM Community Member, who is an expert on Wikidata structures
 and is tenacious in learning new systems. They have a drive for general knowledge and
 want to highlight underrepresented topics. The second persona is the Knowledge En-
 thusiast, who has no experience with Wikidata, though is potentially interested with it.
 The knowledge enthusiasts value reliability and are sensitive towards their domain of
 interest. Each of the two personas has their own end goal: The WM Community Mem-
 ber wants to understand the knowledge imbalance situation to be able to prioritize her
 actions, while the Knowledge Enthusiast wants to have an understanding of the quality
 of general knowledge and identify topic imbalances.

 Usability Testing Setup. Now that we have gathered information regarding the users,
 we want to know how users complete tasks using ProWD-V1. From observing the users
 in completing tasks, we could gather requirements on the things to keep and things to
 improve from ProWD-V1, for this purpose, the users participated in a usability testing
 session using six tasks formulated based on the heuristic evaluation and context of use
 of ProWD. From the usability testing, specific requirements in the form of qualitative
 feedback and quantitative data in the form of success rates, time on task, SUS, and UEQ
 were collected. The collected data was then analyzed to measure the impacts of the re-
 design (ProWD-V2). The six tasks were categorized into typical and secondary tasks.
 The typical tasks were: (i) primary tasks, which are tasks to create new dashboard (CN),
 gather info on profile page (PP), compare subclasses (CP), discover insights (AP), and
 (ii) secondary tasks, for which the users are prompted to generate feedback on the land-
 ing page (LP), and the process of opening previously created dashboards (OP), which
 are the generic experience of new and returning users. The selected topic for the testing
 is “humans with the inventor occupation.” This topic was selected as inventors are gen-
 erally known to the public, e.g., Albert Einstein. In the testing sessions, we observed
 how the users conducted the tasks and instructed them to think aloud to identify any
 cognitive obstacles throughout the testing sessions.

 Post-test and Documentation. For analysis purposes, the screen and audio of the test-
 ing session were recorded. The user interview took 30-60 minutes each and required a
 similar amount of time to evaluate and analyze. After the usability testing session, the
 users answered a usability survey which consists of SUS and UEQ. Gathered from the


                                           19
User-Centered Design for Knowledge Imbalance Analysis: A Case Study of ProWD


 testing, the qualitative feedback suggests that even with their pre-existing knowledge,
 WM Community Members are still confused about the profile creation section of the
 application. The terms used on ProWD-V1 are still rather confusing and figuring out
 the facets and attributes of the profile becomes more difficult. Meanwhile, the Knowl-
 edge Enthusiasts were confused from the get-go, they neither had an idea of what the
 data shown means and how it is important or relevant to them, nor did they compre-
 hend the visualizations the application provides. To simplify, coming into ProWD-V1,
 the users are faced with foreign terms, coupled with confusing navigation and lack of
 documentation, the users get easily frustrated.

 5     Redesigning ProWD

 Now that we have gathered the context of use and user requirements of ProWD, alter-
 native design solutions were formulated. At this stage, several design tools and methods
 were utilized in the process of redesigning the application, from creating a user journey
 to further analyze where ProWD can become helpful for the users to an in-depth analy-
 sis of the 6 tasks. The user requirements also gave insights in the information the users
 want and need from the application. Hence an information architecture was created to
 map these information so that the users can find them more intuitively. Then a proto-
 type of ProWD-V2 was created based on the analysis of the user requirements using
 the tools previously mentioned.

 5.1   User Journey Mapping

 As previously mentioned, each persona has their own end goal in doing and complet-
 ing their job. Understanding how ProWD could help these personas reach their goals
 helped us orient the application towards the users’ needs. For this purpose, a customer
 journey map was created. “A journey map is a visualization of the process that a per-
 son goes through in order to accomplish a goal.” Journey maps can help determine the
 users’ frustration, pain points, and delight. [5] The end goals of the personas which
 were identified from the interviews highlighted possible opportunities in which ProWD
 can become a helpful tool for these personas. For the WM Community Members, their
 end goal is to “be able to understand the knowledge imbalance situation better.” ProWD
 can be helpful to this persona for comparing projects so that they can focus their efforts
 better by also creating an easily identifiable and comparable metric. As for the Knowl-
 edge Enthusiasts whose end goal is to “be able to have an understanding of the quality
 of general knowledge and identify topic reliability,” ProWD can be helpful to identify
 dominating or popular topics in general knowledge.

 5.2   Task Analysis and Information Architecture of ProWD

 To analyze the efficiency of the 6 tasks previously tested, a task analysis is done to
 break-down the tasks to a finer scale. As ProWD visualizes knowledge imbalance, the
 tasks are partially cognitive and physical which creates a challenge in doing task anal-
 ysis. To tackle this, a hierarchical analysis of physical subtasks was performed so that
 the users’ physical interaction with the application could be broken down into its el-
 ements and analyzed to minimize any unnecessary flow. One example of a task with


                                            20
User-Centered Design for Knowledge Imbalance Analysis: A Case Study of ProWD


 both physical and cognitive challenges is the Compare Page (CP task) shown in Fig. 3.
 An example of minimization of a subtask is done to the “Select or Edit the Comparison
 Dimension” subtask, which in ProWD-V1 required the user to do tedious actions of
 around 11 steps to simply edit the comparison dimensions. The task analysis simplified
 the process by decreasing the action to just 5 steps in ProWD-V2, this optimization is
 done to each physical subtask.




                        Fig. 3. Task analysis for the Compare Page (CP) Task


      For the more cognitive tasks, we analyze things that can be improved based on the
 user feedback from the usability testing sessions. The user journey map (Sec. 5.1) shows
 that ProWD can help the WM Community Member persona by “creating an easily iden-
 tifiable and comparable metric,” the creation of this metric can also be helpful to tackle
 the cognitive task to “Get insight from the imbalance difference” as seen in Fig. 3.
 Hence, the Gini coefficient was selected as a metric for imbalance. The Gini coefficient
 is a rough measure of the amount of imbalances in wealth distribution with a value of 0
 (ideally balanced) to 1 (totally imbalanced), which is visualized by using the so-called
 Lorenz curve. It has been used as a measure of inequality in the economic field by cal-
 culating the Gini coefficient for income distribution of each country around the world
 to measure the wealth inequality. This research utilizes the Gini coefficient to visualize
 the imbalance in information wealth.10 Other than the mentioned examples, the require-
 ments previously gathered also shows the need to provide additional information, e.g.,
 “what does ProWD enable?” and “how do I navigate ProWD?”. Now that we have a
 plan on the information we want to add and dismiss in the form of information and fea-
 tures for ProWD-V2, an information architecture blueprint was created. An example of
 this information architecture activity is the mapping of the content within the compare
 page, which now includes the Gini coefficient comparison, the shared and unique prop-
 erties of each subclass, additional documentation for each data, this mapping process is
 done for each feature within ProWD-V2.

 5.3     Prototype of ProWD V2
 Now that each feature’s plan is mapped, it is time to actualize these improvements into
 the form of an actual application by creating a prototype. The improvements done are of
 two kinds: (1) changes done based on the more generic UI/UX elements categorization,
 10
      https://en.wikipedia.org/wiki/Gini coefficient


                                                 21
User-Centered Design for Knowledge Imbalance Analysis: A Case Study of ProWD


 and (2) a more specific categorization based on tasks exclusive to ProWD’s system. The
 UI/UX elements improved aspects are those of (1a) the types of information presented,
 which in the new design, an addition of a new visualization of topic imbalance using the
 Lorenz curve to represent the Gini coefficient as mentioned in Sec. 2. A new function
 to be able to view properties exclusive to compared subclasses using set operations is
 also incorporated in ProWD-V2. Based on the (1b) data visualization element, to aid
 the users in comparing data visually, bar charts are used to represent the information
 over using donut charts previously used in ProWD-V1. (1c) the flow of interaction is
 also modified. The modification of the flow is the result of the task analysis previously
 done, an example of this is within ProWD-V2, after the dashboard creation process, the
 users are immediately redirected into their new dashboard instead of having to browse
 for it in ProWD-V1.




                            Fig. 4. Compare page of ProWD-V2



     In regard to (1d) the layouting of components, modifications in ProWD-V2 allow
 the users to do less scrolling as all information can be seen in one page. Another im-
 portant element is (1e) the words or vocabulary used to deliver the information. An ex-
 ample of an improvement in this regard is renaming “Profiles” as “Dashboards”, since
 according to the feedback from the test-participants, the term “profile” is commonly
 understood as a user profile, while the behavior of the feature is more similar to that
 of a dashboard. Instead of the “Class-Facet-Attribute configuration”, we used the term
 “topic” throughout the application, as this term topic again more commonly understood.
     This would also tie-in with the function of ProWD, which is to visualize topics of
 interest. Other modification of vocabulary are renaming “Multi-Dimensional Analysis”
 as “Discover” and the “Gini Coefficient” as “Topic Imbalance”. Last but not least, (1f )
 the colors were changed in ProWD-V2. A colour palette was created as a guideline for
 the design of ProWD-V2, this helps to create a internal consistency for components and


                                           22
User-Centered Design for Knowledge Imbalance Analysis: A Case Study of ProWD


 actions within ProWD. A predominantly plain white background is also used to create
 a minimalistic interface which helps to highlight the presented data.
     The more task-specific improvements of the application concern (2a) the landing
 page. By presenting an easy and simple tagline, the users are presented with a simple
 definition of the function of ProWD. Another characteristic within the landing page
 is an onboarding feature to help the users understand the concepts and background of
 Wikidata and ProWD. Generally, the idea of the changes on the landing page is to
 provide information the users need to understand and use ProWD’s features. Regarding
 modifications more specific to the (2b) dashboard creation task, users now are only
 required to input the “class” and “filters” instead of having to select specific attributes
 and naming the dashboard immediately. Examples are also provided to assist the users
 in understanding the dashboard creation process.
     Stepping into the main features of the application, (2c) within the profile feature
 page, a component was added to specifically give more information to the users when
 they need it, with other modifications pointing into the previously elaborated UI/UX
 elements improvements. The (2d) compare page was modified to create a more efficient
 flow when the users want to further specify the dimensions of the comparison they want
 to make, while (2e) the multi-dimensional analysis page, which is called the “discover
 page” on ProWD-V2, was altered to visualize the information in a less textual form.
 An example of our improvement results, can be seen in Fig. 4 which is for the compare
 page.

 5.4   ProWD V2 Implementation
 The prototype was then implemented using ReactJS11 and Flask.12 It can be accessed on
 https://prowd.id.13 The flow of data begins from the front-end of the application sending
 a request to the back-end which then fetches the live data from Wikidata query.14 By
 using live data provided by Wikidata’s endpoint, we get the benefit of having directly
 updated data of the items in Wikidata. However, fetching live data also has its limitation
 in that it limits us to only be able to fetch 10,000 items at once.
     When an analyzed topic consists of more than 10,000 items, the system will notify
 the user that the displayed data is in fact only a sample of the population. These 10,000
 items are selected based on the Wikidata SPARQL query service’s default indexing. The
 properties of the item, not including the external identifiers, will be considered as the
 wealth of each item. By assuming the properties to represent the (knowledge) wealth of
 each item, we can measure the imbalances of the knowledge provided by those items
 by comparing the number of distinct properties each item has for a certain class.

 6     Evaluating the Redesigned ProWD
 After the redesigned ProWD (ProWD-V2) was implemented, measuring the effects of
 the improvement effort could give us an insight into how UCD affected the usability
 11
    https://reactjs.org/
 12
    https://flask.palletsprojects.com/en/1.1.x/
 13
    A demo video of ProWD-V2 is available: https://bit.ly/prowd-v2-demo
 14
    https://query.wikidata.org/


                                            23
User-Centered Design for Knowledge Imbalance Analysis: A Case Study of ProWD


 of the application. To do so, we used several quantitative metrics which were measured
 in both usability testing sessions. As previously mentioned, the users fill in the SUS
 and UEQ after the usability testing session, while the success rate and time-on-task is
 gathered from the session recordings. To be able to compare the performance of the
 two versions, the second usability testing used the same six tasks tested during the first
 testing sessions, with slight adjustments to fit the changes in the flow of ProWD-V2.
     An example of the adjustment is to test the Open Previous task (OP Task) last in-
 stead of second, as in ProWD-V2, the users do not need to search for the new dash-
 board after the creation process. The participants of this second usability testing were
 the same as those in the first session, except that one user was unable to participate in
 the second session due to health-related issues. In this case, a new test-participant, rep-
 resented by the same persona as the dropped-out user, was appointed. Testing with the
 same users might raise a concern regarding the bias which may be brought by the users’
 familiarity with the application. Nevertheless, as the system has changed substantially
 from ProWD-V1 to ProWD-V2, the effect of application familiarity would not affect
 the test results severely.


 6.1   Quantitative Metrics and Analysis

 The SUS, UEQ, success rate, and time-on-task were compared and analyzed. The SUS
 results show an increase of 27 points for the two personas, promoting ProWD from
 being a grade F (39.75) to a grade C (66.75) application based on the SUS benchmark
 as mentioned in Sec. 2. This score of 66.75 suggests that ProWD’s usability is barely
 below average on the SUS benchmark. The SUS score for the Knowledge Enthusiast
 persona is lower than that of the WM Community Member with the scores of 59.5 and
 74 respectively. The SUS results also show that most of the users strongly agreed on the
 question stating that “the system requires them to learn many things prior to using the
 application”.




                             Fig. 5. UEQ Results for Each Scale


                                            24
User-Centered Design for Knowledge Imbalance Analysis: A Case Study of ProWD


     As seen in Fig. 5, the UEQ scores show an increase on each of the measured
 scales with the highest increase on the perspicuity scale. Though the perspicuity of
 ProWD-V2 is better than the one of ProWD-V1, it is still the lowest being above av-
 erage as opposed to good and excellent for the other scales. The scales with the highest
 scores are novelty and attractiveness. The low perspicuity score is also aligned with the
 strongly agreed SUS statement previously discussed. This suggests that the users think
 that the application is more attractive and easier to digest compared to the previous
 version, though further research might be needed to make things clearer for the users.
     The success rate increase of 25.9% implies that on ProWD-V2, users are more
 likely to successfully complete tasks. There are only 2 failed task runs on ProWD-V2 as
 compared to 13 failed task runs on ProWD-V1. The specific task with the highest
 increase in success rate is the Create New (CN) task where the users create a new
 dashboard, though it is the task with the lowest success rate compared to other tasks
 on ProWD-V2. This may suggest that the biggest hurdle in utilizing ProWD-V2 is
 where the users are initializing a dashboard, which may also correspond with the low
 perspicuity based on the UEQ. The average task completion time shows that users take
 the longest time on the Profile Page task (PP) on ProWD-V2. This suggests that the
 users might need more time to complete each subtask within the Profile Page as com-
 pared to the time needed in the same page on ProWD-V1. Though with the increase in
 time on PP Task, the success rate of the same task is higher on ProWD-V2 compared
 to ProWD-V1.

 6.2   Qualitative Feedback
 Generally, the usability has improved according to the quantitative metrics. Though
 to gather more task and user-specific feedback, the qualitative feedback needs to be
 taken into account. The qualitative feedback of ProWD-V2 indicates a generally pos-
 itive reception of the new design. The improvements done on the types of informa-
 tion presented aspect are the strongest changes which affected the feedback positively.
 The users stated, “This page is nice, easy to understand, (at first glance) it looks sci-
 entific though is actually simple to use.” The new visualizations and added features
 on ProWD-V2 resulted in positive feedback from the users. The improvement which
 seems to be the weakest in effect is the layouting/placement aspect where the test-
 participants’ sentiments toward the changes does not differ greatly.
     Other than the commentary feedback, the users’ behaviour throughout the testing
 session was taken into account. When creating a new dashboard, users tended to imme-
 diately input instead of exploring the examples. This behavior caused the users to mis-
 understand the necessary inputs to create a correct dashboard. Within the dashboard,
 the tabular information is still misunderstood by the users. This causes them to take a
 longer time to assess the other information in the dashboard. This feedback shows that
 there is room for improvement, pointing to the iterative nature of UCD.

 7     Conclusions
 Systems regarding abstract concepts, such as knowledge graphs and their imbalances,
 can benefit from adapting UCD to improve their usability. With ProWD not having an


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User-Centered Design for Knowledge Imbalance Analysis: A Case Study of ProWD


 existing user base, we had to select appropriate test-participants who are critical towards
 such a system and fit with the context of use. The redesign process considered UI/UX
 elements and task-specific improvements, resulting in a significant increase wrt. the
 SUS and UEQ metrics. Moreover, users are more likely to complete tasks successfully
 by 25.9% on ProWD-V2 compared to ProWD-V1. For future work, we plan to con-
 duct more iterations of UCD on ProWD, expand the 10,000 items limit, and streamline
 ProWD to regular activities by the Wikimedia community.


 Acknowledgements

 Our research was supported by the project grant “Knowledge Graph-based AI – Analy-
 sis and Applications” by Universitas Indonesia. We thank Dinda Mutiara Qur’ani Putri
 for her help in analyzing the interview data. We also thank the anonymous reviewers
 for their detailed feedback. We are grateful to Lydia Pintscher and Elisabeth Giesemann
 for their support in the creation of a blog post of this research work.15


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