A Study of Gjestvang and Singh Randomized Response Model Using Ranked Set Sampling

In this chapter, the authors investigate the performance of the Gjestvang and Singh randomized response model for estimating the mean of a sensitive variable using ranked set sampling along the lines of Bouza. The proposed estimator is found to be unbiased, and a variance expression is derived. Then a simulation study is carried out to judge the magnitude of relative efficiency in various situations. At the end, the proposed model is assessed based on real secondary data applications. A set of SAS codes is also included.

Item Count Technique in Ranked Set Sampling

In situations where the estimation of the proportion of sensitive variables relies on the observations of real measurements that are difficult to obtain, there is a need to combine indirect questioning techniques. In the present work, the authors will focus on the item count technique, with alternative methods of sampling, such as the ranked set sampling. They are based on the idea proposed by Santiago et al., which combines the randomized response technique proposed by Warner together with ranked set sampling. The authors will carry out a simulation study to compare the item count technique under ranked set sampling and under simple random sampling without replacement.

Some evidences and applications of the randomized response crossed model in a survey of sensitive population behaviors

Surveying human behaviors, especially in demographic, social, medical and public health research, often involves sensitive issues. Posing direct inquiries about stigmatizing or threatening topics may lead survey participants to refuse to answer or to give untruthful responses. Nonresponse and misreporting denote measurement errors that are difficult to treat and are likely to yield unreliable analyses of the surveyed topics. This problem can be mitigated by adopting survey methods that enhance anonymity and respondent cooperation. One possibility is to create a trustful and confidential relationship between the interviewer and the survey participants. Alternatively, it is possible to fully protect privacy by adopting indirect questioning procedures that elicit information without posing sensitive questions directly. We consider both above-mentioned possibilities showing the results of a real study which explores the effectiveness of the randomized response crossed model proposed by Lee et al. (2013) to produce prevalence estimates for two sensitive traits, cannabis use and its legalization.

Bayesian Estimation ofWarner’s Randomized Response Technique with Transmuted Kumaraswamy Prior

In recent time, the Bayesian approach to randomized response technique has been used for estimating the population proportion especially of respondents possessing sensitive attributes such as induced abortion, tax evasion and shoplifting. This is done by combining suitable prior information about an unknown parameter of the population with the sample information for the estimation of the unknown parameter. In this study, possibility of using a transmuted Kumaraswamy prior is raised, yielding a new Bayes estimator for estimating population proportion of sensitive attribute for Warner’s randomized response technique. Consequently, the proposed Bayes estimator with transmuted Kumaraswamy prior is compared with existing Bayes estimators developed with a simple beta and Kumaraswamy priors in terms of their mean square error. The proposed estimator competes well with the existing estimators for some values of population proportion. The performances of Bayes estimators were also compared using some benchmark data.

Using the Randomized Response Technique to Investigate Illegal Fishing and Contribute to Abalone Management in Northern California

<p>Illegal fishing has detrimental environmental and social impacts, but these effects are difficult to mitigate without reliable estimates of fisher non-compliance. Methods used by fisheries managers to estimate illegal fishing often require indirect estimation of poaching using biological, economic, or sociological indicators. This study presents a unique application of the randomized response technique (RRT) for direct estimation of non-compliance in the Northern California recreational red abalone (Haliotis rufescens) fishery. Using an anonymous paper-based compliance and sociodemographic survey of recreational fishers in Sonoma and Mendocino Counties, I estimate 29% non-compliance with the daily take limit, 23% with the minimum size limit, 19% with licensing laws, and 15% with the annual take limit and among the general population. No significant relationship between the socio-demographic variables gathered (age, income, county of residence, fishing experience) and RRT survey responses indicates that no clear profile can be ascertained to help identify potential violators. However, visitors have higher non-compliance estimates for all regulations except daily take limits, for which an estimated 72% of locals violate vs. only 18% of visitors. These rule-specific violation estimates allow for the development of efficient management priorities, as managers may target specific measures or user groups. Further research should develop quantitative RRT estimates of illegal take, and explore violation drivers operating within the fisher population.</p>

Using the Randomized Response Technique to Investigate Illegal Fishing and Contribute to Abalone Management in Northern California

<p>Illegal fishing has detrimental environmental and social impacts, but these effects are difficult to mitigate without reliable estimates of fisher non-compliance. Methods used by fisheries managers to estimate illegal fishing often require indirect estimation of poaching using biological, economic, or sociological indicators. This study presents a unique application of the randomized response technique (RRT) for direct estimation of non-compliance in the Northern California recreational red abalone (Haliotis rufescens) fishery. Using an anonymous paper-based compliance and sociodemographic survey of recreational fishers in Sonoma and Mendocino Counties, I estimate 29% non-compliance with the daily take limit, 23% with the minimum size limit, 19% with licensing laws, and 15% with the annual take limit and among the general population. No significant relationship between the socio-demographic variables gathered (age, income, county of residence, fishing experience) and RRT survey responses indicates that no clear profile can be ascertained to help identify potential violators. However, visitors have higher non-compliance estimates for all regulations except daily take limits, for which an estimated 72% of locals violate vs. only 18% of visitors. These rule-specific violation estimates allow for the development of efficient management priorities, as managers may target specific measures or user groups. Further research should develop quantitative RRT estimates of illegal take, and explore violation drivers operating within the fisher population.</p>

Role of Hydrocolloids in the Structure, Cooking, and Nutritional Properties of Fiber-Enriched, Fresh Egg Pasta Based on Tiger Nut Flour and Durum Wheat Semolina

The aim of this work concerns the manufacturing process of fresh egg tagliatelle labeled as a “source of fiber” based on tiger nut flour and wheat semolina. An attempt to improve the quality attributes and cooking properties of the obtained product was made by means of structuring agents. More specifically, a combination of three hydrocolloids (carboximethylcellulose, CMC; xanthan gum, XG; and locust bean gum, LBG) was tested. A Box–Behnken design with randomized response surface methodology was used to determine a suitable combination of these gums to achieve fewer cooking losses, higher water gain and swelling index values, and better texture characteristics before and after cooking. Positive effects on textural characteristics were observed when incorporating XG into the pasta formulation. Cooking and fiber loss also significantly diminished with the XG-CMC combination over 0.8%. No significant effect was found for the other evaluated parameters. A synergistic interaction between LBG and XG was only significant for the water absorption index. The cooked pasta was considered a source of fiber in all cases.