Attending to risk in sequential sampling plans

Researchers typically tackle questions by constructing powerful, highlyreplicated sampling protocols or experimental designs. Such approaches often demand large samples sizes and are usually only conducted on a once-off basis. In contrast, many industries need to continually monitor phenomena such as equipment reliability, water quality, or the abundance of a pest. In such instances, costs and time inherent in sampling preclude the use of highlyintensive methods. Ideally, one wants to collect the absolute minimum number of samples needed to make an appropriate decision. Sequential sampling, wherein the sample size is a function of the results of the sampling process itself, offers a practicable solution. But smaller sample sizes equate to less knowledge about the population, and thus an increased risk of making an incorrect management decision. There are various statistical techniques to account for and measure risk in sequential sampling plans. We illustrate these methods and assess them using examples relating to the management of arthropod pests in commercial crops, but they can be applied to any situation where sequential sampling is used.

Implementing integrated coastal zone management through the use of coastal action plans: lessons from Victoria

There are currently no performance indicators in place for assessing the successful implementation of Victoria,'s strategic plans (Coastal Action Plans, CAPs) in achieving Integrated Coastal Zone Management (ICZM) at a regional level. This article explores the findings of a study which assessed the success of the approach adopted in Victoria under the State Coastal Management Act 1995 to implement ICZM through CAPs. The study developed a set of criteria for measuring this success. We conclude with a discussion of how appropriate such an approach may be in other jurisdictions.

Evaluation of fixed sample-size plans for Plutella xylostella (Lepidoptera: Plutellidae) on broccoli crops in Australia

Fixed sample-size plans for monitoring Plutella xylostella (L.) (Lepidoptera: Plutellidae) on broccoli and other Brassica vegetable crops are popular in Australia for their simplicity and ease of application. But the sample sizes used are often small, ≈10–25 plants per crop, and it may be that they fail to provide sufficient information upon which to base pest control decisions. We tested the performance of seven fixed sample-size plans (10, 15, 20, 30, 35, 40, and 45 plants) by resampling a large data set on P. xylostella in commercial broccoli crops. For each sample size, enumerative and presence-absence plans were assessed. The precision of the plans was assessed in terms of the ratio of the standard error to the mean; and at least 45 and 35 samples were necessary for the enumerative and presence-absence plans, respectively, to attain the generally accepted benchmark of ≤0.3. Sample sizes of 10–20 were highly imprecise. We also assessed the consequences of classifications based on action thresholds (ATs) of 0.2 and 0.8 larvae per plant for the enumerative case, and 0.15 and 0.45 proportion of plants of infested for the presence-absence case. Operating characteristic curves and investigations of the frequency of correct decisions suggest improvements in the performance of plans with increased sample size. In both the enumerative and presence-absence cases, the proportion of incorrect decisions was much higher for the lower of the two ATs assessed, and type II errors (i.e., failure to suggest pest control upon the AT is exceeded) generally accounted for the majority of this error. Type II errors are the most significant from a producer’s standpoint. Further consideration is necessary to determine what is an acceptable type II error rate.

Additive effect of interferential therapyover pelvic floor exercise alone in the treatment of female urinary stress and urge incontinence: A randomized controlled trial

This pilot study attempted to examine the additional efficacy of interferential therapy in reducing the symptoms of urinary stress and urge incontinence. Twenty-four subjects were randomly allocated to the experimental group, which received interferential therapy plus pelvic floor exercises, or the control group, which received pelvic floor exercises only. Treatment was given three times a week for 4 weeks. Subjects were given urinary diaries to record urinary symptoms (including frequency of passing urine and number of times woken by desire to pass urine) for 5 days prior to and after treatment. Perineometer readings, pad weighing test and start/stop test were also performed in a physiotherapy clinic before and at completion of treatment regimes. Significant improvements were observed in all the outcome variables in the experimental group, but in only the perineometer readings in controls. When the changes from pre- to post-treatment were compared between the two groups, four of the dependent variables did not reach statistical significance. Power analysis indicated that the sample size for each group needed to be 70 for all results to be statistically significant. This study shows that interferential therapy plus pelvic floor exercise appears to be a more effective treatment modality than pelvic floor muscle strengthening exercise alone for incontinence, but a larger trial with longer followup is needed before definitive conclusions can be reached.

Floor trading and screen trading : distinctions for practitioners

The creation of an electronic limit order book is discussed as the basis for distinguishing between the floor trading and screen trading of derivative instruments. Distinguishing between FTP and ETP in terms of market transparency allows investors to contemplate the trade-off between the 2 platforms. Distinguishing between FTP and ETP in terms of memory preservation allows practitioners to contemplate the different experiences when analyzing floor data and screen data. A comparable set of floor and screen data is used to examine the impact on the trading dynamics and price discovery of LIFFE's FTSE 100 index futures market when trading is automated on LIFFE CONNECT. The dynamics in the quote change equation is shortened when moving from the floor to screen sample. Using the model's measure of trade informativeness, it is found that in 4 out of 5 daily sub-samples, screen trades are more than twice as informative as floor trades. Variability within a system of equations is explained more by order size history than trade size history.

A systematic approach to writing and rating entrepreneurial business plans

This investigation is part of a series of studies in the field of venture capital deal screening. At issue is the use of theory-based standards for the systematic creation and assessment of entrepreneurial business plans. A synthesis of research-based principles contained in the literature culminated in the formal articulation and operationalization of 10 principles in the form of a questionnaire, titled the Entrepreneurial Business Plan Assessment Regime (EBRAR). The EBRAR can serve as a guide for both writing and rating entrepreneurial business plans. Discussion focuses on the utility of assessment, as well as future research directions.

Is the quality of entrepreneurial business plans related to the outcome of a new venture?

The evaluation of new ventures often involves two key aspects of entrepreneurial business plans: how best to write them and how best to rate (evaluate) them. Ultimately the performance of the venture should be the definitive criterion of quality. Surprisingly, the writing, rating and performance effects of entrepreneurial business plans (EBPs) comprise three related but under researched areas. This paper empirically tested principles for writing and rating entrepreneurial business plans to draw inferences on how to improve the private equity investment evaluation process. A simplified perspective of General Systems Theory guided our empirical investigation of the input and outcome of the VC investment decision. Our empirical investigation reveals that entrepreneurial business plans that comport with the writing principles from the literature improve a new venture’s likelihood of success.

The Pacific OPIC Project (Obesity Prevention In Communities) : action plans and interventions

Background: The Pacific OPIC Project (Obesity Prevention In Communities) includes whole-of-community intervention programs in four countries (Fiji, Tonga, New Zealand, Australia) aimed at reducing the prevalence of overweight and  obesity in youth.

Development of Action Plans: At each intervention site, preliminary interviews  were conducted with youth to identify the potential socio-cultural barriers and  facilitators to healthy eating and regular physical activity in order to attain and sustain a healthy body size. This and other information was presented at a 2-day workshop with community stakeholders, including youth. The participants then prioritised the components for a draft action plan which was later consolidated through further community consultation.

Action Plan objectives: Each action plan had two overall aims: to build  community capacity and to promote healthy weight. The first three objectives in each action plan were on capacity building, social marketing messages, and evaluation. Next were a set of four to five behavioural objectives with associated strategies involving programs, events, social marketing and environmental  change. Lastly, each site had one or two innovative or developmental objectives.

Progress: Interventions began in all sites from 2005, with the action plans guiding implementation priorities. The initial behavioural objective for targeting in Fiji was eating regular breakfast and meals throughout the day, for Tonga it was physical activity, and for Australia and New Zealand it was increasing water consumption and decreasing consumption of sweet drinks.

Conclusions: The action plans have provided the basis for community engagement in the project, the guide to the implementation of activities and the template for the evaluation plan.