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CADDIS Volume 1: Stressor Identification
Summary Tables of Types of Evidence
Types of Evidence that Use Data from the Case
|Type of Evidence
||The biological effect must be observed where and when the cause is observed, and must not be observed where and when the cause is absent.
|Evidence of Exposure or Biological Mechanism
||Measurements of the biota show that relevant exposure to the cause has occurred, or that other biological mechanisms linking the cause to the effect have occurred.
||Steps in the pathways linking sources to the cause can serve as supplementary or surrogate indicators that the cause and the biological effect are likely to have co-occurred.
|Stressor-Response Relationships from the Field
||As exposure to the cause increases, intensity or frequency of the biological effect increases; as exposure to the cause decreases, intensity or frequency of the biological effect decreases.
|Manipulation of Exposure
||Field experiments or management actions that increase or decrease exposure to a cause must increase or decrease the biological effect.
|Laboratory Tests of Site Media
||Controlled exposure in laboratory tests to causes (usually toxic substances) present in site media should induce biological effects consistent with the effects observed in the field.
||The cause must precede the biological effect.
||Knowledge of a cause's mode of action permits prediction and subsequent confirmation of previously unobserved effects.
||Biological measurements (often at lower levels of biological organization than the effect) can be characteristic of one or a few specific causes.
Types of Evidence that Use Data from Elsewhere
Evaluating Multiple Types of Evidence
|Type of Evidence
|Consistency of Evidence
||Confidence in the argument for or against a candidate cause is increased when many types of evidence consistently support or weaken it.
|Explanation of the Evidence
||Confidence in the argument for a candidate cause is increased when a post hoc mechanistic, conceptual, or mathematical model reasonably explains any inconsistent evidence.
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