Hypothesis Tests

Question 1

When we are ‘testing a hypothesis’ what are we actually testing?

Answer 1

how likely something is to occur by chance

Question 2

what can we add to an experiment that gives us a good indication of whether the results are occuring by chance?

Answer 2

a placebo

Question 4

What is a null hypothesis?

Answer 4

It is the hypothesis that there is no signifcant difference between what you are testing and the likliehood of it occuring by chance - you want to disprove the ‘null hypothesis’ , but can only do this if there is a less than 5% likely possibility that the effect occured by chance

Question 5

what can we conclude from a chi squared test result of 0.095?

Answer 5

the probability of an apparrent association like this happening by chance is 0.095 - so we cannot conclude from the data that women have a higher risk of depression than men

Question 6

what does a t-test tell us?

Answer 6

how likely it is that the difference between the means of 2 groups arose by chance

Question 7

what does the ANOVA test tell us?

Answer 7

how likely is it that the variation between the means of a number of groups arose by chance

Question 8

what does the chi-squared test tell us?

Answer 8

how likely it is that the association between the rows and colums of a table arose by chance