Browsing by Subject "Active Learning"

Now showing 1 - 3 of 3

Open Access
Active learning methods based on statistical leverage scores
(2016-08) Orhan, Cem
In many real-world machine learning applications, unlabeled data are abundant whereas the class labels are expensive and/or scarce. An active learner aims to obtain a model with high accuracy with as few labeled instances as possible by effectively selecting useful examples for labeling. We propose two novel active learning approaches for pool-based active learning setting: ALEVS for querying single example at each iteration and DBALEVS for querying a batch of examples. ALEVS and DBALEVS select the most in uential instance(s) based on statistical leverages scores of examples. The rank-k statistical leverage score of i-th row of an n x n kernel matrix K is the squared norm of the i-th row of the matrix U whose columns are the top-k eigenvectors of K. Statistical leverage scores are shown to be useful in matrix approximation algorithms in finding in uential rows of a matrix. ALEVS and DBALEVS assess the in uence of the examples by the statistical leverage scores of kernel matrix computed on the examples of the pool. Additionally, through maximizing a submodular set function at each iteration DBALEVS selects a diverse a set of examples that are highly in uential but are dissimilar to selected labeled set. Extensive experiments on diverse datasets show that the proposed methods, ALEVS and DBALEVS offer more effective strategies in comparison to other single and batch mode active learning approaches, respectively.
Open Access
Do computer games enhance learning about conflicts? A cross-national inquiry into proximate and distant scenarios in Global Conflicts
(Pergamon Press, 2015) Kampf, R.; Cuhadar E.
Interactive conflict resolution and peace education have developed as two major lines of practice to tackle intractable inter-group conflicts. Recently, new media technologies such as social media, computer games, and online dialogue are added to the existing set of tools used for peace education. However, a debate is emerging as to how effective they are in motivating learning and teaching skills required for peace building. We take issue with this question and have conducted a study investigating the effect of different conflict contexts on student learning. We have designed a cross-national experimental study with Israeli-Jewish, Palestinian, and Guatemalan undergraduate students using the Israeli-Palestinian and Guatemalan scenarios in the computer game called "Global Conflicts." The learning effects of these scenarios were systematically analyzed using pre- and post-test questionnaires. The study indicated that Israeli-Jews and Palestinians acquired more knowledge from the Guatemalan game than Guatemalans acquired from the Israeli-Palestinian game. All participants acquired knowledge about proximate conflicts after playing games about these scenarios, and there were insignificant differences between the three national groups. Israeli-Jews and Palestinians playing the Israeli-Palestinian game changed their attitudes about this conflict, while Guatemalans playing the Guatemalan game did not change their attitudes about this case. All participants changed their attitudes about distant conflicts after playing games about these scenarios. © 2014 Elsevier Ltd.
Open Access
Tutorial services for students at Bilkent University an evaluation after five years
(Sense Publishers, 2008) Çelik, B. Keyik; Özdemir, B. Uslu; Verhoeven, John M
To realize our mission as academic coordinators for engineering students at Bilkent University, we facilitate in different ways tutorial services. These focus on the first year courses for physics, mathematics and computer science, which are courses that turn out to be difficult, as students' comments and grades often show. Most tutorial services are realized in cooperation with the Departments. Senior undergraduate students or graduate students are hired to work as laboratory assistants or as homework graders, or to offer recitation classes. During these classes questions are answered, difficult issues are explained, while many exercises are done to gain the necessary routine for applying the theory. Such classes can form together with theory classes and laboratory sessions a consistent unity of different working forms. Besides these services, which are scheduled regularly and for which participation often is included in the grading, we coordinate tutorials on demand, for students asking for them. Another idea behind the tutorial services is that they give the possibility for advanced students to practice their teaching and communication skills. We organize application procedures, hire the students accepted for the job, follow their work with duty reports to be submitted by them, try to coach them in different ways. By participating in workshops, where special attention is given to strategies for active learning, tutors can work for a teaching certificate. After they finished their job satisfactorily, tutors may ask for a 'thank you letter', as a useful academic reference. Everything considered, although the infrastructure for the tutorial services is quite challenging, they form a useful tool for our mission as student coordinators.