OAR Box 1112 

Prepped by Ryan Dugan 

Document Number: 

35) II-C-3C 

Docket Number: 

A-83-22 

Printed 4/16/2008 9:12:07AM Sheet 35 of 97 

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10/3/84 

Expert Selection Protocol -? ^ 

1. INTRODUCTION 

In order to conduct a probabilistic risk assessment of the health 

effects associated with alternative national ambient air quality standards 

(NAAQS) for lead it is necessary to obtain the probabilistic judgments of 

recognized expert scientists and physicians concerning dose/response 

relationships between lead and adverse health effects in human populations. 

Such judgments need to be obtained to produce the required risk estimates 

because of the existence of uncertainty about these dose/response 

relationships. 

The need for probability judgments from recognized experts creates the 

need for two formal processes: a "probability encoding" process which 

culminates in the elicitation of probability judgments from individual 

experts; and, a process by which the experts to be encoded are selected. 

The probability encoding process protocol is addressed in other work. The 

process of selecting experts is addressed here. 

The process of selecting a set of experts to encode is as important as 

the encoding process itself. A balanced set of viewpoints that represents 

the existing diversity of respected and credible expert opinion is desired. 

The following section specifies a method for selecting a group of experts 

that achieves this objective. 

2. GENERAL STEPS IN THE PROCESS 

2.0 Selection Protocol 

Considering the time and resource constraints which limit the scope of 

a selection procedure, the following protocol is specified. 

(a) An initial list of 5 to 10 names for each health effect will be 

constructed by OAQPS following consultation with ECAO staff, CD authors, 

and OAQPS contractors. 

(b) OAQPS staff and contractors will take this information, determine 

the number of experts that can affordably be encoded, and select a list of 

experts that represents the range of credible, respected opinion on each 

health effect at the exposure levels of interest for the risk assessment 

program. 

3. SELECTION CRITERIA 

The following suggests factors that are relevant in the selection ov 

people for the encoding process: 

(a) familiarity with the problem -

(i) degree of familiarity with the adverse effect at the rel' 

dose levels (e.g., may be actively involved in resear-; 

directly addresses the issue at hand); 
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(ii) degree of involvement in organizing and/or participating in 

workshops and/or conferences related to lead and its health 

effects; 

(iii) degree of involvement in producing the lead CD. 

(b) credentials - this type of factor concerns the individuals general 

credibility as an expert: 

(i) scope of publications; 

(ii) membership on relevant committees (e.g., NAS); 

(iii) general expertise in endpoint of concern; 

(iv) degree of respect among peers. 

(c) technical perspective - this type of factor concerns the technical 

background or perspective of the person, such as, 

(i) whether he or she is a clinical investigator, epidemiologist, 

or toxicologist; 

(ii) the nature of the person's own research; and 

(iii) the person's interpretational orientation. 

(d) availability to participate in the encoding process. 

The intent of the selection process is to utilize the knowledge, 

credibility, and diversity of the scientific community related to each health 

effect in a balanced way. OAQPS staff and contractors assume the lead role 

and responsibility for obtaining acceptable groups of experts.