Ranking scale

Tables I and II present the results of the Work Group discussions for the screening and site-specific level models, respectively. The assessment in these tables is based on a ranking scale between 0 and 100 0 indicates situations where no testing has been attempted and 100 identifies areas where extensive testing has been completed with sufficient post-audits to validate the predictive capability of relevant models. The scores can also be interpreted to mean the extent to which additional field testing would improve our understanding of how well the models represent natural systems. It is important to note that the scores do not indicate model accuracy per se they show the degree to which current field testing has been able to identify or estimate model accuracy.

A ranking scale of nine levels ranging from non-hazardous to extremely hazardous was developed (Tab. 2). The rationale behind the EDAR index is based on averaging out the ecotoxic effects of a given aqueous sample. 

The ranking scale limit values of the index were set considering the results that would be obtained if all tests yielded a response of 20% to the same concentration or dilution. Each interval of the reference scale was arbitrarily fixed according to valued judgment taking into account the authors experience. 

An index based on the sum or average of bioassay end-points is the simplest to devise. In some instances it may be desirable to combine tests of acute lethality with sublethal tests in order to include a spectrum of organisms and/or responses. Indices are easier to construct if toxicity end-points are first translated into toxic units. The numerical values then can be summed like the chemical properties of a sample. An alternative would be to classify results on an ordinal scale (e.g. 0-10) based on the observed severity of effect. The approach is more subjective, but at least it incorporates expert judgement that should enter the assessment of data at some point. A ranking scale allows any kind of environmental measurement to be included in the index. 

Table IV lists the 13 criteria used for ranking those compounds (from among hundreds of potential candidate chemicals) that posed the highest risk to water quality. The 100 highest reported use pesticides were screened. A semi-quantitative ranking scale was developed and applied in selecting 12 priority chemicals (Figure 8). Field monitoring in potential "hot spot" areas was designed to document...

Sometimes geochemical data cannot strictly be used in product-moment correlation of the type described above for they do not fuliil the requisite conditions. For example, some populations are not normally distributed and others include oudiers. An alternative, therefore, to Pearson s product-moment coefficient of linear correlation is the Spearman rank coefficent of correlation, usually designated r. This type of correlation is applicable to major or trace element data measured on a ranking scale rather than the equidistant scale used in Pearson s product-moment correlation. The Spearman rank correlation coefficient is calculated as follows ... 

Methods for predicting qualitative effects are difficult to find or to validate. In many cases, the prediction indicates merely whether there will be degradation, no change, or enhancement of environmental quality. In other cases, qualitative ranking scales (from 1 to 5,10 or 100) are used. 

This section provides observational assessments used to characterize neurological functions, a description of the behaviors being observed, and possible ranking scales to be used, where applicable. The observed behaviors are innate, that is, they do not need to be taught or shaped. Thus, observations require little or no interaction between the observer and the subject, with the possible exception of holding the rat. Because the observer makes judgments regarding these behaviors, the assessments are subjective. 

A simple 0 to 5 ranking scale can be allocated to each of the progress questions, and a total score can be calculated as a percentage of completion. When applied to the entire system, the individual and total scores will give an overall picture of the safety system implementation progress. This progress report shonld be included in various safety reports and communications. 

A safety examination tool that measures the attitudes, perceptions, and motivation of employees towards safety that influence its safety culture and safety behaviors. It typically consists of a specifically constructed set of questions that are answered with a ranking scale, that are submitted to a sample of the workforce, the results of which are analyzed for possible safety improvements. 

Table 10 is a condensed version of the Detection ranking scale. It pertains to what the verification system and/or controls in place are expected to accomplish. 

Ranking scale is representative of a majority of airports, but may not fit the control and operation stracture for every airport. 

---