research

Question 1

Analyzing data - 3 ways

Answer 1

Relative Ratio - RR
Odd Ratio - OD
Risk Difference ARD - absolute risk

Question 2

do you need a confidence interval?

Answer 2

Yes - you need to be certain within a certain degree - 95% is standard (actually 95.5)

all measure of effect are uncertain

Question 3

risk ratio - table for four

Answer 3

people who have dogs smile more -

35/50, 12/28
.7/.525 = 1.33

Question 4

intervention goes first

Answer 4

if you are comparing two active interventions - you can choose which goes first

Question 5

what does 1.33 mean?

> 1 increases the risk of the event occurring

if =1 - there is no affect

Answer 5

in RR - where number is >1 - means the intervention (have a dog) increases of risk of smiling

if <1 0 means having a dog dog not increase the risk of smiling

Question 6

Odds of an Event?

OR >1 - intervention increases the odds

if OR = 1 - no difference

Answer 6

figure out the odds of both groups, divide the two and get the odds ratio

35/15; 12/28

2. 33/ .428
3. 44

odds are that if you have a dog, you are five times as likely to smile

Question 7

What does 5.44 mean?

Can be expressed in a couple of ways

Answer 7

odds are 5 times more that if you have a dog you will smile

and

can be expressed as a percentage - 544% higher than the odds in the control group

Question 8

Risk difference - an absolute measure - not a ratio -

RD>1 intervention increases the risk of event

RD<1:
intervention reduced the risk of event

?????

HERE _ point of no effect is ZERO

here - could I say?

having a dog increases the risk of smiles

Answer 8

35/50
12 /40

.7 - .525

subtracting

= .175

??

two ways to express -

1. percentage points

percentage change

percentage point change

2. natural frequencies

Question 9

negative skew vs positive -

negative skew - tail is on left

NEGATIVE IS little and MEAN

Answer 9

mean < median < mode

MEDIAN is always in between these two with either skew

Question 10

positive skew?

Big meanie is RIGHT

tail is on RIGHT

Answer 10

mean > median > mode. Generally speaking, extreme values in skewed distributions affect the mean,