Decision unbiased

Historically, physical evidence has taken on increasing importance in criminal matters. Court decisions have consistentiy looked askance at a defendant s admissions of guilt and even question eyewitness testimony. Physical evidence has traditionally been viewed as impartial and unbiased, and not subject to the problems associated with confessions made by an accused or the testimony of witnesses. 

The evaluation of hazards posed to human health by toxic airborne chemicals is one of the common tasks employed in industrial hygiene. This process requires the collection of air samples to estimate air concentrations of specific substances inhaled by workers which can then be compared with standards and guides of acceptable exposure. Thus air sampling directly influences the formulation of important decisions. If air samples underestimate exposures, the consequence may be death or occupational disease. Conversely, overestimating exposures may result in the institution of unnecessary controls. Since either form of error is undesirable, it is fundamentally important that air sampling accurately define the extent of hazard. This requires that air samples be collected according to scientific, unbiased schemes for estimating exposures to toxic airborne chemicals. 

Once the data are computed in this fashion, there are three numbers to associate with each point on the surface of Figure 2 the probability that the environment is OK the probability that it is NOT OK and the probability that no decision can be made on the basis of one exposure estimate. Therefore, a complete comparison between Figure 2 and the three decision criteria in this report requires careful consideration of ten 3-dimensional surfaces. This is not practical, so it is necessary to define contours of significance which can be used to provide a rapid, easily understood comparison of the different behavior of the three decision criteria. The first is the contour of unbiased decisions, and the other three are the contours marking the boundaries of the regions where one decision is the most likely outcome of evaluating the meaning of one representative exposure estimate. 

The Unbiased Decision Contour. A workplace which produces an unbiased decision is defined for purposes of this paper as one for which P(0K) = P(N0T OK). From Equation 4, (0 ) is represented by the area in the tail of pdjj(X) below the AL. From Equation 5, P(N0T OK) is represented by the area in the tail of... 

There are two important observations to be made concerning the contour of unbiased decisions. The first is that for workplaces lying to the left of the unbiased decision contour, P(0K)... 

P(N0T OK) while for workplaces lying to the right of the unbiased decision contour, P(N0T OK) > P(0K). The second is that since our decision criteria have been derived to provide high confidence in the decisions which are made, it frequently happens that the most likely outcome from a trial involving one sample taken from a workplace lying close to the unbiased decision contour is that a decision cannot be made with sufficient confidence. Because of this, it is important to define additional decision boundaries. 

To derive the unbiased decision contour, note that P( < AL)... 

The critical value of CVp has to be lower than the maximum permissible true value (e.g. lower than CVp 0.128 when there is no bias). The maximum permissible value of the true CVp will be referred to as its "target level". In order to have a confidence level of 95% that a subject method meets this required target level, on the basis of CVp estimated from laboratory tests, an upper confidence limit for CVp is calculated which must satisfy the following criterion reject the method (i.e. decide it does not meet the accuracy standard) if the 95% upper confidence limit for CVp exceeds the target level of CVp. Otherwise, accept the method. This decision criterion was implemented in the form of the Decision Rule given below which is based on assumptions that errors are normally distributed and the method is unbiased. Biased methods are discussed further below. 

The next section of the business plan defines the critical risks and opportunities of the business. Here, the plan should outline the major strengths and weakness of the proposed business and describe the opportunities and risk associated with the program if implemented (as formulated in the SWOT analysis). This information, both positive and negative, must be presented in an unbiased manner so that an informed decision can be made about moving forward with the program. 

The presentation of results should support an unbiased understanding of the results of the exposure assessment to enable the members of the target groups to make informed and independent decisions. This requires a basic understanding of the exposure process (the model from source to dose/burden) and at least an intuitive competence to understand the quantitative data and results in nature and magnitude. The selected scenario, data, model assumptions, results and inherent uncertainties should be communicated in an understandable and scientifically accepted presentation format. Presentations should be tailored to address the questions and information needs of the different audiences. To handle the different levels of sophistication and detail needed, it may be useful to design a presentation in a tiered format where the level of detail increases with each successive tier (USEPA, 1997b). 

It is possible to terminate an MCDA early we can use it simply to place options before us in an unbiased way, leaving the final decision to policy makers (thus it operates as a multicriteria analysis, MCA). 

By the same token, no one pretends that commercials are thorough, sober, unbiased presentations of anything, let alone complex medical topics. None of the other empowerments—investigating a factory s pollution, or making investment decisions for a 401 (k)—is based on advertisements. So how the heck did these two opposites get hooked together ... 

How do you ensure that your interview with a patient is unbiased and thorough How do you make sure that you do not forget to ask something Your decision with regards to counter prescribing or referral to a GP will be based on the information you manage to obtain from the patient. 

It is difficult to prevent some personal biases from entering professional attitudes. However, professionals serving the public interest must render an unbiased presentation of the facts if the role of public opinion in the decision-making process is to be valid. Professionals must adopt an unbiased attitude, even in those circumstances where they have personal beliefs which may differ from the facts. 

Future trends in trace element analysis will put even greater pressure on the need to provide unbiased determinations. Increasing interest in the role of trace elements in health and disease will provide the stimulus for the better provision of quantitative determinations on which important decisions are made (Centers for Disease Control, 1991 Moukarzel et al., 1992). Increased public awareness and legislation are likely to bring about substantial reductions in the currently acceptable levels of occupational and environmental exposure to some non-essential elements such as lead, cadmium and aluminium. Determinations that are made as part of the assessment of such exposure will need to be both carefully validated and reproducible over many years or decades (Braithwaite and Brown, 1988 Brown, 1991), which will have a serious impact on laboratory costs. However, reproducible trace element determination with a low bias in biological fluids represents the cornerstone of any proper understanding of the role of trace elements in human health and disease. 

Meta-analysis may make small studies meaningful by providing a means to combine the results with those of other similar studies to enable estimates of an intervention s efficacy. Small trials may not be able to test a hypothesis, but they may provide valuable information of treatment effects using confidence intervals (Edwards et ai, 1997). Similarly, others argue that a sample size that results in a p value of 0.1 can be informative and decisions have to be made even where there is no trial evidence, a little unbiased evidence is better than none. A study might have only limited ability to detect an effect, but participants should be allowed to make an autonomous decision. 

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