week 5- making sense of statistical data

Question 1

confidence intervals

Answer 1

an estimates range of values that might contain the true effect of a treatment.
95% level- means that 95% of the time, the CI will contain the true value.

Question 2

correlation

Answer 2

the relationship between two variables 
correlation does not equal causation 
3 factors 
- strength (r-value) 
- direction (positive or negative) 
- statistical significance (P-value)

Question 3

strength (r-value)

Answer 3

a factor of correlation

how similar the two variables are from -1 to +1

strength can be the same regardless of direction. so -0.6 is the same as -0.6

0= no correlation and 1= perfect correlation

Question 4

direction (positive or negative)

Answer 4

a factor of correlation

refers to which direction the independent and dependent variables move

positive: when the DV and IV both move in the same direction. eg. both increase or both decrease.
negative: when the variables move in opposite directions. eg. increase in exercise and decrease in body fat.

Question 5

statistical significance (P-value)

Answer 5

factor of correlation

we need all three elements to tell weather a relationship is significant or not.

eg. r=0.72, p=0.02
there is a strong positive relationship between the independent and dependent variable.

CORRELATION DOESNT EQUAL CAUSATION