When “Don’t Know” Indicates Nonignorable Missingness: Using the Estimation of Political Knowledge as an Example

The conventional procedure for measuring political knowledge is treating nonresponses such as “don’t know” as incorrect responses and counting the number of “correct” responses. In recent times, increasing attention has been paid to partial knowledge hidden within incorrect and nonresponses. This article explores partial knowledge indicated by incorrect and nonresponses and considers nonresponses as nonignorable missingness. We propose a model that combines the shared-parameter approach presented in the literature on missing data mechanisms and the methods of item response theory. We show that the proposed model can determine whether the people with nonresponses should be treated as more or less knowledgeable and detect whether it is appropriate to pool nonresponses and incorrect responses into the same category. Furthermore, we find partial knowledge hidden within women’s nonresponses, which confirms the possibility of the exaggeration of the gender gap in political knowledge.

Investigating the Effects of Learning Tasks on Vocabulary Knowledge

<p>This thesis looks at whether different kinds of vocabulary learning tasks result in different types of word knowledge. In almost every study that has investigated the effects of tasks on vocabulary learning; the only aspect of word knowledge that was tested was meaning and form. Since researchers agree that knowing a word involves much more than knowing its meaning and form, prior research may have measured partial knowledge of only one of several aspects of knowledge. In order to determine the effects of vocabulary learning tasks, several aspects of knowledge should be tested. The experiments in this thesis investigated how vocabulary learning tasks affect both receptive and productive knowledge of five aspects of word knowledge: orthography, association, syntax, meaning and form, and grammatical functions. In the first of six experiments, the effects of incidental learning from reading and explicit learning from word pairs on word knowledge were compared. The results indicated that gains in knowledge tend to increase as the number of repetitions increases; however, partial gains from an informative context may be reduced or eliminated if followed by a less informative context. The results also showed that learning from word pairs contributed to surprisingly greater gains in all of the aspects. In the second experiment, two tasks (learning from glossed sentences, and learning from word pairs) were compared to determine the effects of context and synonymy on vocabulary knowledge. It was found that the subjects gained greater knowledge of unknown words that had high frequency synonyms than for those with less frequent synonyms. The results also indicated that a single context may have little effect on acquisition. In the third, fourth and fifth experiments, the effects of receptive and productive learning tasks on vocabulary knowledge were examined. The results indicated that productive learning from word pairs may be more effective at developing productive knowledge while receptive learning from word pairs may be more effective at increasing receptive knowledge. The sixth experiment investigated the effects of receptive and productive learning from word pairs on communication. It was found that the receptive task may be superior in improving comprehension, and the productive task may be better suited to facilitating writing. Taken as a whole, this thesis indicates that measuring multiple aspects of vocabulary knowledge both receptively and productively may provide a much more accurate assessment of the relative efficacy of vocabulary learning tasks. Moreover, it suggests that different tasks may have a different effect on vocabulary knowledge.</p>

Investigating the Effects of Learning Tasks on Vocabulary Knowledge

<p>This thesis looks at whether different kinds of vocabulary learning tasks result in different types of word knowledge. In almost every study that has investigated the effects of tasks on vocabulary learning; the only aspect of word knowledge that was tested was meaning and form. Since researchers agree that knowing a word involves much more than knowing its meaning and form, prior research may have measured partial knowledge of only one of several aspects of knowledge. In order to determine the effects of vocabulary learning tasks, several aspects of knowledge should be tested. The experiments in this thesis investigated how vocabulary learning tasks affect both receptive and productive knowledge of five aspects of word knowledge: orthography, association, syntax, meaning and form, and grammatical functions. In the first of six experiments, the effects of incidental learning from reading and explicit learning from word pairs on word knowledge were compared. The results indicated that gains in knowledge tend to increase as the number of repetitions increases; however, partial gains from an informative context may be reduced or eliminated if followed by a less informative context. The results also showed that learning from word pairs contributed to surprisingly greater gains in all of the aspects. In the second experiment, two tasks (learning from glossed sentences, and learning from word pairs) were compared to determine the effects of context and synonymy on vocabulary knowledge. It was found that the subjects gained greater knowledge of unknown words that had high frequency synonyms than for those with less frequent synonyms. The results also indicated that a single context may have little effect on acquisition. In the third, fourth and fifth experiments, the effects of receptive and productive learning tasks on vocabulary knowledge were examined. The results indicated that productive learning from word pairs may be more effective at developing productive knowledge while receptive learning from word pairs may be more effective at increasing receptive knowledge. The sixth experiment investigated the effects of receptive and productive learning from word pairs on communication. It was found that the receptive task may be superior in improving comprehension, and the productive task may be better suited to facilitating writing. Taken as a whole, this thesis indicates that measuring multiple aspects of vocabulary knowledge both receptively and productively may provide a much more accurate assessment of the relative efficacy of vocabulary learning tasks. Moreover, it suggests that different tasks may have a different effect on vocabulary knowledge.</p>

THE INFLUENCE OF KNOWLEDGE, RELIGIOSITY, AND POCKET MONEY ON STUDENTS' INTEREST FOR SAVING IN SHARIA COMMERCIAL BANKS

This research aims to determine the effect of Knowledge, Religiosity, and Pocket Money on interest for saving in shariah banks. Data collection techniques using questionnaires and using primary data with a population of 503 students from the Faculty of Economics at the State University of Jakarta. The sample selection was done by proportional random sampling technique which resulted 205 samples. Data analysis uses several regression analyses with the help of SPSS. The results showed: (1) Partial knowledge has a positive and significant effect on interest in saving. (2) Partial religiosity does not affect interest in saving. (3) Partial pocket money has a positive and significant effect on interest in saving. (4) Knowledge, religiosity and pocket money simultaneously affect interest in saving.

Privacy Preserving Reputation Calculation in P2P Systems with Homomorphic Encryption

In this paper, we consider the problem of calculating the node reputation in a Peer-toPeer (P2P) system from fragments of partial knowledge concerned with the trustfulness of nodes which are subjectively given by each node (i.e., evaluator) participating in the system. We are particularly interested in the distributed processing of the calculation of reputation scores while preserving the privacy of evaluators. The basic idea of the proposed method is to extend the EigenTrust reputation management system with the notion of homomorphic cryptosystem. More specifically, it calculates the main eigenvector of a linear system which models the trustfulness of the users (nodes) in the P2P system in a distributed manner, in such a way that: 1) it blocks accesses to the trust value by the nodes to have the secret key used for the decryption, 2) it improves the efficiency of calculation by offloading a part of the task to the participating nodes, and 3) it uses different public keys during the calculation to improve the robustness against the leave of nodes. The performance of the proposed method is evaluated through numerical calculations.

A partial knowledge of friends of friends speeds social search

Milgram empirically showed that people knowing only connections to their friends could locate any person in the U.S. in a few steps. Later research showed that social network topology enables a node aware of its full routing to find an arbitrary target in even fewer steps. Yet, the success of people in forwarding efficiently knowing only personal connections is still not fully explained. To study this problem, we emulate it on a real location-based social network, Gowalla. It provides explicit information about friends and temporal locations of each user useful for studies of human mobility. Here, we use it to conduct a massive computational experiment to establish new necessary and sufficient conditions for achieving social search efficiency. The results demonstrate that only the distribution of friendship edges and the partial knowledge of friends of friends are essential and sufficient for the efficiency of social search. Surprisingly, the efficiency of the search using the original distribution of friendship edges is not dependent on how the nodes are distributed into space. Moreover, the effect of using a limited knowledge that each node possesses about friends of its friends is strongly nonlinear. We show that gains of such use grow statistically significantly only when this knowledge is limited to a small fraction of friends of friends.