Optimal eradication: when to stop looking for an invasive plant

The notion of being sure that you have completely eradicated an invasive species is fanciful because of imperfect detection and persistent seed banks. Eradication is commonly declared either on an ad hoc basis, on notions of seed bank longevity, or on setting arbitrary thresholds of 1% or 5% confidence that the species is not present. Rather than declaring eradication at some arbitrary level of confidence, we take an economic approach in which we stop looking when the expected costs outweigh the expected benefits. We develop theory that determines the number of years of absent surveys required to minimize the net expected cost. Given detection of a species is imperfect, the optimal stopping time is a trade-off between the cost of continued surveying and the cost of escape and damage if eradication is declared too soon. A simple rule of thumb compares well to the exact optimal solution using stochastic dynamic programming. Application of the approach to the eradication programme of Helenium amarum reveals that the actual stopping time was a precautionary one given the ranges for each parameter.

Stepping Stones Triple P: A pilot study to evaluate acceptability of the program by parents of a child diagnosed with an Autism Spectrum Disorder

The experience of parents of children with Autism Spectrum Disorder (ASD) in standard parenting programs has not been researched, although anecdotal evidence suggests that they do not find them acceptable. Forty-two parents of children with ASD were asked to view a DVD explaining individual parenting strategies from Stepping Stones, a new branch of the Triple P program targeted specifically at parents of children with disabilities. Parents were asked to rate each strategy for acceptability, usability and behavioural intention, i.e., their intention to use the strategy. Additionally, parental attributions and parental perceived control were explored as possible barriers to positive evaluations of Stepping Stones parenting strategies. A focus group of parents was used to gather more detailed parent response to the program. Parent responses to the program were generally positive and attribution of the child's behaviour to uncontrollable factors was found to predict higher ratings of usability. The results were interpreted within the context of Weiner's attributional theory and the theory of reasoned action. The limitations of this study and suggestions for future research are discussed. (c) 2005 Elsevier Ltd. All rights reserved.

Measuring parent satisfaction with a neonatal hearing screening program

The primary aim of the present study was to investigate parent satisfaction with a neonatal hearing screening program through use of a valid and reliable questionnaire developed for this purpose (Parent Satisfaction Questionnaire with Neonatal Hearing Screening Program; PSQ-NHSP). Eighty parents whose children had received hearing screening participated in this study. High levels of satisfaction were reported with more than 90% of parents satisfied with all aspects of the program. The PSQ-NHSP was analyzed for validity and reliability and demonstrated excellent internal consistency reliability (sigma = 0.94) and excellent test-retest reliability (rho = 0.97). Content validity of the PSQ-NHSP was partially established by reviewing available literature on parent satisfaction studies in other pediatric health-care service programs. Construct validity of the PSQ-NHSP was indicated by a significant positive relationship between overall satisfaction and the three specific dimensions in the questionnaire. The satisfaction questionnaire was found to be a useful instrument for identifying service shortfalls, and routine use of the PSQ-NHSP in other neonatal hearing screening programs is recommended.

Implementation of Triple P-Positive Parenting Program in Hong Kong: Predictors of programme completion and clinical outcomes

This study examined the effectiveness of the Triple P-Positive Parenting Program in a government child health service delivery context with Chinese parents in Hong Kong. Specifically, the study sought to identify pre-intervention variables that might predict programme outcomes such as, level of clinical improvement and programme completion. Participants were 661 parents of pre-school and primary aged children participating in a group version of the Triple P-Positive Parenting Program. There were significant decreases in disruptive child behaviours, levels of parenting stress, general stress and anxiety and an increase in parenting sense of competence. Greater change in reports of child behaviour problems was related to lower levels of family income, new immigrant family status, and higher pre-intervention levels of parenting stress. The present study provides a profile of parents who are most likely to benefit from parent training programmes.