IR WEEK 3

Question 1

what would the null hypothesis be for a chi square analysis?

Answer 1

There is no relationship between variable A and variable B

Question 2

what would the research hypothesis be for a Chi Square analysis

Answer 2

there is a relationship between variable A and variable B

Question 3

Describes and predicts genotype and allelic frequencies in a non-evolving population

Answer 3

hardy weinberg principle and equation

Question 4

what are the assumptions of the hardy weinberg principle

Answer 4

large populations
random mating
no mutation or mutation equilibirum
no migration
no selection: genotypes reproduce with equal success

Question 5

frequency of the A allele

Answer 5

p

Question 6

frequency of the a allele

Answer 6

q

Question 7

defined as the ability of an analytical method to assess small variations of the concentration of the analyte

Answer 7

analytical sensitivity

Question 8

defined as the ability of an assay to determine specifically the concentration or detection of the target analyte in the presence of interfering substances

Answer 8

analytical specificity

Question 9

defined as the fraction of patients with a disease that the assay correctly identifies

Answer 9

clinical sensitivity

Question 10

defined as the fraction of patients without a disease that the assay correctly identifies

Answer 10

clinical specificity

Question 11

Equation for % sensitivity
proportion of positive tests among patients that have the disease

Answer 11

True Pos/ (True Pos+ False Neg)

Question 12

Equation for % specificity proportion of negative tests among patients that are healthy

Answer 12

True Neg
_______________________
(False Pos + True Neg)

Question 13

positive predictive value

Answer 13

True pos
___________________
(True Pos+ False Pos)

Question 14

Disease Prevalence

Answer 14

(TP+ FN)
________________
TP+FN+FP+TN

Question 15

how to choose a non parametric test

Answer 15

if you cannot assume a normal/ guassian population
if variance is unequal
if you have very small samples
if you have nominal or ordinal data

Question 16

non parametric version of the t-test for comparing two samples. requires at least ordinal scale

Answer 16

Mann-Whitney U test

Question 17

One way parametric version of the ANOVA; assumes ordinal data; three or more groups

Answer 17

Kruskal-Wallis one way ANOVA

Question 18

non parametric version of paired parametric tests; compares two paired groups

Answer 18

Wilcoxon Matched Pairs signed-Ranks

Question 19

non parametric version of a repeated-measures ANOVA; compares three or more paired groups; followed with post tests

Answer 19

Friedman Test

Question 20

can handle outliers skewed data and small samples better than parametric, chance of making type two error is increased

Answer 20

non parametric test

Question 21

examines the question of whether two categories of classification are independent of each other

Answer 21

contingency tables

Question 22

chi square formula

Answer 22

expected count

Question 23

if chi square value is greater than the critical value……

Answer 23

then their is a significant difference and you can reject the null hypothesisf

Question 24

if the chi square is less than the critical value………

Answer 24

there is not a significant difference, fails to reject the null hypothesis