Question 1

Reliability refers to:

Accepted Answer

Reliability in research and measurement contexts refers to the consistency of a measure or observation over time. If a method or tool yields similar results under consistent conditions, it is considered reliable.

Question 2

A simple match statement by a forensic expert:

Accepted Answer

A simple match statement by a forensic expert typically does not use statistical terms, as it is a straightforward comparison without involving statistical analysis or probability categories.

Question 3

Nicholas was brought in for questioning and asked to provide his fingerprints. Based on fingerprint evidence, he was excluded as a suspect. This means that the fingerprints found at the crime scene were:

Accepted Answer

The fingerprints found at the crime scene did not match Nicholas's fingerprints, indicating they belonged to a different individual.

Question 4

Ebony works as a fingerprint examiner. In a blind test, she is asked to determine if the two fingerprints match. She does not know that it is the same pair of fingerprints she has evaluated a few months before. To compare her previous decision with her current decision would allow us to measure:

Accepted Answer

Test-retest reliability measures the consistency of a test or measurement over time by having the same examiner (or test) evaluate the same material or data on two different occasions. In this scenario, Ebony's ability to produce the same decision on the same pair of fingerprints at two different times is a measure of test-retest reliability.

Question 5

Diego is a forensic expert who is asked to testify whether the wound that the victim died from came from a knife found in the suspect's car. Diego has confirmed a high level of agreement between the knife and the wound, which in his professional opinion means the wound was produced by the knife in question. This type of opinion is called a(n):

Accepted Answer

Individualization in forensic science refers to the process of conclusively identifying the source of a piece of evidence, such as matching a wound to a specific knife, based on unique characteristics.

Question 6

According to the text, forensic experts testifying in court often cannot provide scientific data about error rates. Instead, they are more likely to invoke their:

Accepted Answer

Forensic experts often rely on their extensive experience in a specific field, such as fingerprint examination, to provide testimony in court when scientific data about error rates is not available.

Question 7

According to the text, it is not easy to calculate the false positive rate for most types of trace evidence because:

Accepted Answer

The difficulty in calculating the false positive rate for most types of trace evidence is attributed to forensic examiners' reluctance to participate in studies of error rates. This reluctance can stem from various reasons, including concerns about the implications of such studies on the credibility of their work or the forensic field in general.

Question 8

A survey was administered to high school seniors in Anytown. According to the survey results, fewer than 0.5% of the students drove drunk in the previous 6 months. A month later, the survey was repeated and it again indicated that fewer than 0.5% of Anytown seniors drove drunk in the previous 6 months. Based on this information, the survey has:

Accepted Answer

The survey showing consistent results over two different instances (less than 0.5% of students drove drunk in the previous 6 months) indicates high test-retest reliability, meaning the survey produces stable and consistent results over time.

Question 9

A shoe imprint left at the crime scene will be much more helpful if it comes from a(n) _____ shoe.

Accepted Answer

A well-worn shoe will have unique wear patterns and characteristics that can help investigators link the imprint to a specific shoe and potentially to a specific individual.

Question 10

Temporal consistency is sometimes referred to as:

Accepted Answer

Temporal consistency refers to the stability of a measure or test over time, which is assessed by test-retest reliability. This involves administering the same test to the same subjects at two different points in time and then correlating the scores to evaluate consistency.

Question 11

A false positive means that a(n):

Accepted Answer

A false positive occurs when an expert incorrectly identifies a match or a positive outcome when, in reality, no such match exists. This is common in various fields, including medical testing, where a test might indicate the presence of a disease when the patient is actually disease-free, or in forensic science, where evidence might wrongly be matched to a suspect.

Question 12

A qualitative statement made by an expert when presenting evidence is:

Accepted Answer

A qualitative statement made by an expert when presenting evidence typically refers to a non-statistical statement about the strength of a match, relying on the expert's judgment and experience rather than on numerical data.

Question 13

Two fingerprint examiners have independently concluded that the suspect can be excluded as the source of the print. This scenario illustrates the _____ of fingerprint analysis as a measure.

Accepted Answer

Interrater reliability refers to the degree of agreement among raters or evaluators. If two fingerprint examiners independently arrive at the same conclusion, it demonstrates high interrater reliability in the fingerprint analysis process.

Question 14

If the imprint came from a popular type of Adidas sneaker, it reflects _____; if the imprint has a unique pattern of wear and tear, it reflects _____.

Accepted Answer

Group characteristics are those that can identify a category or group (like a type of Adidas sneaker), while individual characteristics are unique features (like a specific pattern of wear and tear) that can identify a specific item or person.

Question 15

Which one of the following situations would be an example of a false negative error?

Accepted Answer

A false negative error occurs when a test incorrectly indicates that a condition does not exist when it actually does. In this context, an expert declaring there is no match when it actually matches is an example of a false negative error.

Question 16

Forensic identification is less likely to result in inconclusive findings when a _____ left at the crime scene is _____.

Accepted Answer

A clear tire tread impression provides a more definitive pattern for comparison, making it less likely to result in inconclusive findings compared to partial or smudged evidence.

Question 17

Bullet-matching results:

Accepted Answer

Bullet-matching techniques have faced significant scrutiny and criticism for their lack of consistency and proven reliability. Despite their widespread use in forensic investigations and trials, numerous studies and reports have highlighted the limitations and potential inaccuracies of bullet-matching methodologies, leading to questions about their validity and the safety of using such evidence in court.

Question 18

Validity refers to:

Accepted Answer

Validity in research or measurement context refers to the extent to which a tool, test, or method measures what it is intended to measure. It is about the accuracy and appropriateness of the conclusions drawn from the data.

Question 19

Among the types of questionable forensic evidence that has been used in courts for decades, the text mentions the chemical composition of the bullets and handwriting analysis. What is the reason these are not valid techniques?

Accepted Answer

The error rate for both the analysis of the chemical composition of bullets and handwriting analysis is too high, making them unreliable and thus not valid techniques for forensic evidence.

Question 20

Shelly testifies in court that the DNA recovered at the crime scene is likely to come from the suspect because less than 0.0001% of population have this specific genetic marker. This type of identification is called a(n):

Accepted Answer

Match plus statistics refers to a situation where a match is made between evidence and a suspect, and statistical analysis is used to demonstrate the rarity or commonality of the match within the general population, thus providing a more precise measure of the evidence's significance.

Quiz 4: The Psychology of Forensic Identification: Dna, Fingerprints, and Physical Trace Evidence