Research Methods & Evidence-Based Practice Flashcards

A forensic scientist reports a likelihood ratio of 1,000 for a DNA match. What does this indicate?

Answer: The probability of a match is 1,000 times greater under the prosecution hypothesis than the defense hypothesis

A likelihood ratio compares the probability of the evidence under two competing hypotheses; LR=1,000 means the evidence is 1,000 times more probable if the prosecution's hypothesis is true.

Which type of validity concerns whether a forensic assessment instrument actually measures what it claims to measure?

Answer: Construct validity

Construct validity evaluates whether an instrument truly measures the theoretical construct it is designed to assess.

A coroner uses a structured decision-making protocol that integrates local mortality statistics with individual case findings. This exemplifies which pillar of evidence-based practice?

Answer: Clinical expertise integrated with best research evidence and local context

Evidence-based practice integrates the best available research evidence with practitioner expertise and local/patient context.

In a forensic study, a Type II error would mean:

Answer: Failing to detect a true difference between groups

A Type II (beta) error is a false negative: failing to reject the null hypothesis when it is actually false.

Which sampling method would be most appropriate to ensure representation of all forensic subspecialties in a national survey study?

Answer: Stratified random sampling

Stratified random sampling divides the population into subgroups (strata) and randomly samples from each, ensuring representation of all subspecialties.

A forensic medicine researcher conducting a multi-site study uses a data safety monitoring board (DSMB). What is the primary purpose of this oversight body?

Answer: To review accumulating data and recommend stopping or continuing the trial for safety or efficacy reasons

A DSMB independently monitors interim data to protect participant safety and can recommend early termination if harm or clear benefit is established.

Which analytic approach is used to control for time-varying confounders in a longitudinal forensic cohort study when traditional regression is insufficient?

Answer: Marginal structural models with inverse probability weighting

Marginal structural models (MSMs) with inverse probability weighting are designed to address time-varying confounders that are also affected by prior exposure.