Selma Gurler

The effects of conflict resolution and peer mediation training on Turkish elementary school students’ conflict resolution strategies

The effectiveness of conflict resolution and peer mediation (CRPM) training among 10‐ and 11‐year‐old elementary school students was examined. The CRPM training program consisted of skills, such as understanding the nature of interpersonal conflicts, communication, anger management, negotiation and peer mediation. The research was carried out using pretest/posttest‐quasi‐experimental design. The sample included 591 students; 326 in the experiment and 265 in the control group. A self‐report questionnaire which consisted of four subscales (integrative/constructive, smoothing, forcing and withdrawing/avoidance) was used to collect data related to conflict resolution strategies. The CRPM training program significantly improved students’ ‘integrative/constructive’ conflict resolution strategy and reduced their ‘forcing’ and ‘withdrawing/avoidance’ strategies. However, no statistically significant difference was found in the ‘smoothing’ strategy. When boys’ and girls’ results were examined separately, boys’ ‘integrative/constructive’ conflict resolution strategy scores increased after the training, while their ‘forcing’ scores decreased. CRPM training was not found to be effective in girls.

On the Mean Remaining Strength of the k-Out-of-n:F System with Exchangeable Components

In this article, we consider the mean remaining strength of a k-out-of-n:F system in the stress–strength setup for the exchangeable components. We provide some results for parallel and series systems under this setup, where X1, X2, …, Xn are the strengths of the components designed under the common stress. An illustrative example is given for the k-out-of- n:F system using the multivariate FGM distribution.

Revisiting multivariate likelihood ratio ordering results for order statistics

In this article, we establish some results concerning the likelihood ratio order of random vectors of order statistics in the case of independent but not necessarily identically distributed observations and for the case of possible dependent observations. Applications of these results to provide comparisons of conditional order statistics are also given.

On the mean remaining strength at the system level for some bivariate survival models based on exponential distribution

In this paper, we consider the mean remaining strength at the system level of two-component parallel and series systems in the case of possibly dependent components which are subject to a common stress. We assume that the strengths of the components have FGM, Freunds, Marshall-Olkin and Block-Basus bivariate exponential models. A numerical study based on the generated data set is performed to obtain the maximum likelihood estimates of the mean remaining strength for two-component parallel system in the stress-strength setup.

The effects of conflict resolution and peer mediation training on primary school students' level of aggression

This study aims to analyse the effects of conflict resolution and peer mediation (CRPM) training on the levels of aggression of 10–11-year-old Turkish primary school students. The study was conducted using a quasi-experimental design. The experimental group of the study included 347 students (173 girls, 174 boys), and the control group had 328 students (158 girls, 170 boys). Data for the research were collected using the ‘Aggression Scale’. Data analyses revealed that CRPM training was effective in lowering the aggression scale scores of the students. Boys seem to have benefited more from the training than girls. CRPM training was found to reduce student aggression which may lead to more constructive, restorative and peaceful behaviour in classroom and school settings. Since less energy and time will have to be allocated to resolving problem behaviour, academic success may increase, and a safer school atmosphere may be attained.

Parameter estimation of generalized Rayleigh distribution based on ranked set sample

ABSTRACT Ranked set sampling (RSS) is an efficient method for estimating parameters when exact measurement of observation is difficult and/or expensive. In this paper, we provide maximum likelihood estimation of the shape and scale parameters concerning generalized Rayleigh distribution based on RSS and its some modifications. We compare the biases, mean squared errors and relative efficiencies of estimators in simple random sampling, RSS, extreme RSS and median RSS with different set and cycle sizes. Comparison of the mean squared errors of estimators in RSS for the case of imperfect ranking are also given. Monte Carlo simulation study is performed by using Mathematica 11.0 with 10,000 repetitions.

Partial groups ranked set sampling and mean estimation

ABSTRACT Ranked set sampling (RSS) is an advanced sampling method which is very effective for estimating mean of the population when exact measurement of observation is difficult and/or expensive. Balanced Groups RSS (BGRSS) is one of the modification of RSS where only the lowest, the median and the largest ranked units are taken into account. Although BGRSS is advantageous and useful for some specific cases, it has strict restrictions regarding the set size which could be problematic for sampling plans. In this study, we make an improvement on BGRSS and propose a new design called Partial Groups RSS which offers a more flexible sampling plan providing the independence of the set size and sample size. Partial Groups RSS also has a cost advantage over BGRSS. We construct a Monte Carlo simulation study comparing the performance of the mean estimators of the proposed sampling design and BGRSS according to their sampling costs and mean squared errors for various type of distributions. In addition, we give a biometric data application for investigating the efficiency of Partial Groups RSS in real life applications.

Combining the Information of Multiple Ranker in Ranked Set Sampling with Fuzzy Set Approach

Ranked set sampling (RSS) is a useful alternative sampling method for parameter estimation. Compared to other sampling methods, it uses the ranking information of the units in the ranking mechanism before the actual measurement. The ranking mechanism can be described as a visual inspection of an expert or a highly-correlated concomitant variable. Accuracy for ranking of the sample units affects the precision of the estimation. This study proposes an alternative approach, called Fuzzy-weighted Ranked Set Sampling (FwRSS), to RSS for dealing with the uncertainty in ranking using fuzzy set. It assumes that there are K (\(K>1\)) rankers for rank decisions and uses three different fuzzy norm operators to combine the decisions of all rankers in order to provide the accuracy of ranking. A simulation study is constructed to see the performance of the mean estimators based on RSS and FwRSS.

Mean Estimation Based on FWA Using Ranked Set Sampling with Single and Multiple Rankers

The Ranked Set Sampling (RSS) is an advanced sampling method which improves the precision and accuracy of the mean estimator. In RSS, the units in the random sets which are drawn from a population are ranked by a ranking mechanism, and one of these ranked units is sampled from each set with a specific scheme. Ranking the units (visually or by a concomitant variable) could not be perfect because there is an uncertainty in decision making about the rank of a unit. In this study, we propose a fuzzy set perspective for RSS and an estimator for the population mean based on Fuzzy Weighted Average (FWA) operator. A real data application is given to illustrate the new approach for the single and multiple rankers.