Replacing eye trackers in ongoing studies: A comparison of eye-tracking data quality between the Tobii Pro TX300 and the Tobii Pro Spectrum

The Tobii Pro TX300 is a popular eye tracker in developmental eye-tracking research, yet it is no longer manufactured. If a TX300 breaks down, it may have to be replaced. The data quality of the replacement eye tracker may differ from that of the TX300, which may affect the experimental outcome measures. This is problematic for longitudinal and multi-site studies, and for researchers replacing eye trackers between studies. We, therefore, ask how the TX300 and its successor, the Tobii Pro Spectrum, compare in terms of eye-tracking data quality. Data quality—operationalized through precision, accuracy, and data loss—was compared between eye trackers for three age groups (around 5-months, 10-months, and 3-years). Precision was better for all gaze position signals obtained with the Spectrum in comparison to the TX300. Accuracy of the Spectrum was higher for the 5-month-old and 10-month-old children. For the three-year-old children, accuracy was similar across both eye trackers. Gaze position signals from the Spectrum exhibited lower proportions of data loss, and the duration of the data loss periods tended to be shorter. In conclusion, the Spectrum produces gaze position signals with higher data quality, especially for the younger infants. Implications for data analysis are discussed.     

Application of Anbar's Approach to Hypothesis Testing to Detect the Difference between Two Proportions

In this paper, Anbar's (1983) approach for estimating a difference between two binomial proportions is discussed with respect to a hypothesis testing problem. Such an approach results in two possible testing strategies. While the results of the tests are expected to agree for a large sample size when two proportions are equal, the tests are shown to perform quite differently in terms of their probabilities of a Type I error for selected sample sizes. Moreover, the tests can lead to different conclusions, which is illustrated via a simple example; and the probability of such cases can be relatively large. In an attempt to improve the tests while preserving their relative simplicity feature, a modified test is proposed. The performance of this test and a conventional test based on normal approximation is assessed. It is shown that the modified Anbar's test better controls the probability of a Type I error for moderate sample sizes.     

Maintaining the Professional Integrity of Federal Statistics

Transactional analysis can be used to analyze personal interactions between consulting statisticians and their clients. The Parent-Adult-Child model has recently been refined to consist of six states by subdividing the Parent and Child ego states. The authors briefly define the six ego states (Nurturing Parent, Critical Parent, Adult, Adapted Child, Free Child, and Rebellious Child) and describe their occurrence during statistical consultations. Recommendations are given for identifying the ego states, setting realistic goals for relationships, and modifying unsatisfactory transactions.     

Distribution of the Activity Time in Network Analysis: A Critical Revisit with a Gamma Alternative

Network analysis is an important technique for project management. However, the current literature is biased toward beta distribution for modeling activity times. In this article, we have critically examined the role of beta distribution. It has been shown that beta distribution plays no specific role. Further, the method for calculating the chance of project completion must be revised. We have accordingly suggested an alternative modeling in terms of gamma distribution and proposed how to calculate the chance of project completion by taking into consideration both critical and noncritical paths. For demonstration purposes, we have considered a small project.     

Children living with parental substance misuse: A cross‐sectional profile of children and families referred to children's social care

Parental substance misuse is a significant public health and children's rights issue. In the United Kingdom, social workers frequently work with children and families affected by substance misuse. However, relatively little is known about this population, particularly at point of referral to children's social care. This paper reports on the largest known study of parental substance misuse as a feature of children's social care work in England. The paper provides a cross‐sectional profile of 299 children living with parental substance misuse and referred to children's social care in one local authority in England. Data were collected from social work case files at the point of referral to social care about the child, family, the wider environment, and parental substance misuse. The findings show that children affected by parental substance misuse frequently had other support needs relating to their well‐being and mental health. Children were also likely to be experiencing other parental and environmental risk factors. The significant historical—and in some cases intergenerational—social care involvement for some families indicates potential issues with the capacity of services to meet needs. Recommendations for practice are discussed with a particular focus on the need for early, comprehensive support for children and families.     

A Note on Determining Optimal Selling Price and Lot Size Under All-Unit Quantity Discounts

A recent study conducted by Abad [1] described a method of determining the optimal price and lot size when the supplier offers all-unit quantity discounts. The author developed a procedure using centralized and decentralized approaches. According to the author's suggestion, further study is necessary to determine if the decentralized approach always provides an optimal solution. In the present study, an attempt is made to investigate the uniformity between the centralized and decentralized approaches and to verify whether the decentralized approach always yields optimal solutions.     

An Inventory Model with Planned Shortages and Price Dependent Demand

Previous research has yielded a procedure for a retailer to determine the optimal lot size and selling price when a supplier offers all-unit quantity discounts and demand is a decreasing function of price. In this paper, we extend that research by allowing for shortages. An algorithm is presented that determines the optimal lot size, order level, and selling price for a class of demand functions, including the constant price-elasticity and linear demand functions.     

Parental substance misuse and statutory child protection in England: Risk factors and outcomes

Parental substance misuse is a significant child welfare issue and associated with increased risk of child maltreatment. The aim of the present study was to understand what social care outcomes children who live with parental substance misuse have, and to assess factors associated with those social care outcomes over a two-year period. The paper reports on a retrospective longitudinal study of 299 children all living with parental substance misuse and referred to one local authority in England. Data were collected from children's social work case files about procedural social care outcomes and factors which may be associated with those outcomes. Using cluster analysis, a new typology of children's longitudinal trajectories through the children's social care system was developed, consisting of five distinct types. Analysis indicated that some children received too little intervention from children's social care despite ongoing concerns, while other children were potentially unnecessarily caught up in the social care system. Factors associated with children having the poorest outcomes were: caregiver instability resulting from substance misuse, parenting capacity and household instability. The study's findings indicate that some children who live with parental substance misuse are at significant risk of harm, but others are not and may be better supported through non-statutory services such as early help.