Hypothesis Testing I

who was the person who started statistics in the 8th century AD

Al-Kalil

what four things are included in statistics

designing experiements

collecting and analysing data

summarising information for understanding

interpretation of the analyses and drawing conclusions

what are 4 things that you could be answering in a research question

comparing groups

risk factor identification

prediction of outcomes

evaluation of diagnostic tests

what is nominal data

no ordering of the categories like different countries or colours

what is discrete data

can take only integer values

example of ordinal data

strongly disagree, disagree, agree, strongly agree

inferential statistics

based on data from a sample you are trying to reach conclusions on that applies to the entire population

what are the important things to ahve in a sampel

every element form the population has the same probability to be in the sample which is done through being random and representative

what letter represents the mean of the population

mu

what are the two things you need for a confidence interval

standard deviation

mean of the population

what does the 95% mean

if you use a different sample and repeat the same calculations then you will get a different CI, but in 95% of cases the CI will contain the true value

what is a hypothesis

an educated guess about something based on facts that haven’t been proven

what are the symbols for null and alternative hypothesis

H0 ad H1

what is the definition of the P vlaue

the probability of getting the observed effect if the null hypothesis is true

when is ANOVA used

comparing the means of more than two groups provided the samples are independent and normally distributed

what is the point of a power analysis

determine the minimal sample size for a study

what is a sample size

the minumum number of observations needed to observe an effect of a certain size with a given power level

what is a type I error and which thing does it come up in

false positive in significance level of a test

what is a type II error and where does it come up

false negative in power of a study

what is the expected effect size

standardised way of expressing the magnitude of the expected result of the study and indicates the practical significance of research