Evidentiality, in language, is evidence that supports the truthfulness of a statement. Scholars generally measure evidentiality by measuring the evidence supporting a statement against the epistemic modality. Epistemic modality is the amount of conviction the scholar has in the person or work of literature giving the evidence. When measuring evidentiality, the scholar usually determines whether the evidence is sensory or hearsay. The scholar may then use this information to determine whether or not the statement is viable, labeling it most likely true or most likely false.
Those gathering information for evidentiality usually begin by discovering how the subject of the statement was observed. For instance, a young woman might say, “My sister’s arm was bleeding.” A scholar studying this statement might question how the young woman knows this. If the statement was observed through hearsay, it is likely the young woman was given this information by a third party and did not observe the statement firsthand.
When dealing with hearsay, a scholar has two choices: label the statement as most likely false, or try to find someone who observed the statement with his or her senses. Statements made through hearsay can become muddled and confused as they are passed from person to person, giving them a relatively low level of epistemic modality. For instance, the young woman’s sister may have only had a paper cut, but the statement was exaggerated by the time it got to the woman herself.
In the above situation, the scholar would probably find someone with sensory evidence supporting the statement. Sensory evidence may be gathered by any one of the five senses: sight, hearing, taste, touch, or scent. Someone who saw the sister may support the statement in question by confirming that he or she saw blood on the sister’s arm. This helps give the scholar more confidence in the statement, but still does not prove or disprove it. For instance, the alleged blood may have been spilled ketchup or ink.
The next step in evidentiality is usually to find someone even closer to the situation, someone who was physically involved with the evidence. In this case, that person might be someone who helped the sister care for her arm, or the sister herself. Someone who helped the sister care for her arm would have sight evidence as well as touch evidence. The person would have seen the severity of the injury and probably touched the wound to clean it or bandage it. The scholar can question this person, determining whether the injury and the blood were indeed as they seemed.
Source evidence is generally deemed the best kind of evidentiality. Here, the scholar goes directly to the source of the statement, or the sister, in this case. The sister experienced the statement, meaning she knows exactly what happened. If the scholar speaks to her and finds the hearsay was correct, the statement may be labeled most likely true.