RSS Evaluative Reporting Flashcards
What type of report provides an assessment of the strengths to be attached to findings?
Evaluative
Synonymous with transposing the conditional - is this type of fallacy?
Prosecutors fallacy
What is probability?
is a measurment of that event will occur
* quantified as a number between 0 and 1
* zero indicates impossibility of the event occuring
* one indicates certainty
What are the rules of probability?
- when an event cannot occur the probability will be 0
- when an event is certain to occur the probability is 1
- the sum of the probabilies of all the outcomes in the sample is 1
- the probability that an even will not occur is equal to 1 - the probability that the event will occur
What are the two factors that are required to determine probability?
- E the event whose probability is being considered
- I the information available to the assessor when the probability of E is being considered
What are the two things that probability can be?
- Objective: a logical measure of chance where everyone would be expected to agree to the value of the relevant probability
- Subjective: measuring the strength of a persons belief in a particular proposition
What is the notation that shows the probability that the accused is guilty given the evidence?
p (G|E)
What is the notation for the probability that the accused is innocent given the evidence introduced?
p (I|E)
What is Bayes Theorem?
Posterior odds = likelihood ratio x prior odds
What is the posterior odds in terms of probabilities?
Pr(Hp|Evidence) / Pr(Hd|Evidence)
Case of Lucia De Berk
- example of prosecutors fallacy
- statistician said the odds were 342 million to 1 that it was a coincidence she had been duty when all incidents occurred
- some deaths she wasnt actually present for
- statistic was recaculated and she was acquitted
What are the two types of samples?
- recovered or questioned samples (unknown origin)
- control or reference sample of known origin
What is relative frequency?
Calculated against the items observed over a period of time or from all DNA profiles in a defined population
How are the figures in the likelihood ratio formed?
- extensive surverys, databases or experimention
- personal experiences and previous casework
What are the two probabilities or likelihoods?
- the likelihood of the evidence if the prosecutions proposition is true
- the likelihood of the evidence if the defence proposition is true