stats tests Flashcards
what are the features of science
FYLYING HARRY POTTER= F H POTER
F- falsfiability= show something to be false
H- hypothesis testing- testible statement
P- Paradigm shift- shared set of assumptions
O- Objectivity- info based on facts you cant argue with
T- Theory construction- theories constructed to make sense of the facts
E- Empirical methods- knowledge gained through carrying out experiments
R- Replicability- something that can be repeated
what is nominal data
data in the form fo categories of showing frequency data
what is ordinal data
ordered in rank position, ordered highest to lowest
what is interval data
fixed unit of measurement, e.g. the time, temperature, weight, height
what is meant by statistically significant
enough evidence/data to support the idea
what is probability
a numerical measure of the likelihood or chance that certain events will occur
- stats test gives teh probability that a particular sample did not occur if teh null hypothesis for the population was true
probability levels or significance level
- usually use 0.05
- expresses a degree of uncertainty
- means there is a 5% chance of teh results occuring if the null hypothesis is true
types of hypothesis
one tailed- form of test used with a directional hypothesis
two tailed- form of test used with a non directoinal hypothesis
what is the calculated value
value of a test statistic calculated for a particular data set
what is the sign test
determine whether the difference we have found is significant
when to use the sign test
SNoRD
Sign
Nominal
Repeated measures
Difference
how to use the sign test
- work out the sign of difference for each participant using the data ( - + =)
- add up number of + and -
- were there more pluses or minuses
- which ever is the lowest of the numbers is the S value- calculated value
- N value is total number of participants minus any = scores
in order to accept hypothesis, calculated value must be equal to or less than the critical value, if it is not then you reject it
what is spearman’s rho
test of correlation between two sets of values
when to use spearman’s rho
COS
Correlation
Ordinal data
Spearman
how to use spearman’s rho
- rank each set of scores separately
in each group from lowest to highest - find the difference between each pair of ranks and square the difference
- add the differences up
- work out the value of rho
calculated value of rho must be equal to or more than the critical value
