nominal data
data in categories (discrete)
ordinal data
quantities that have natural ordering(ranking)
interval data
intervals between each values (temperature in faranhieght)
ratio
interval data with a natural 0 (time)
what is a probability value
Inferential statistics allow researchers to draw conclusions from their findings.
These conclusions are based on the probability of whether a set of results could have occurred by chance (or not).
If the results are not due to chance, then we say that the findings are significant
what is the probability level in psychology
probability level generally chosen in psychology is 5% (p≤0.05). This means that there is a 5% possibility our results occurred randomly
equation for probability
number of particular outcome/ number of possible outcomes
why do we carry out statistical significance
to see how accurately our sample can be generalized to general population
mann-whitney U
the test is used to predicted a difference between two sets of data
the two sets are from an independant group
thew data can be ordinal interval or ratio
level of significance
5% is the general accepted amount t in psychology
5% level of significance meaning that anything less than 5% is significant and null hypothesis is unlikely top be true
anything above 5% is not significant and we reject null hypothesis
mann whitney u process
1- alternative hypothesis and null hypothesis is made
2-record results data -if has the same score in different conditions their data is ignored
3-find the observed value( given in exam)
4- find the critical value ( value that needs to be reached in order for null hypothesis to be wrong)
5state conclusion-observed value more or less than critical if less than null is rejected
wilcoxon
test used to predicted difference between two sets of data
sets of data are from one person( repeated) or matched pair so data is related
data can be ordinal ratio interval
