data analysis Flashcards
what is nominal data
cant be placed in a specific order eg. Sex, ethnicity, party
what is ordinal data
response categories can be placed in rank order eg, likert (agree/disagree), intensity (low/medium/high), education (GCSE, A level)
what is interval data
responses measured on a continuous scale with rank order, eg age, income, vote share
how do you maximise the usefulness of the data
always try to get the highest level of data
define frequency
how many times something happens. indicative of potential analysis
what does standard deviation measure?
the distance of each value from the mean
what is the difference between small and large Standard deviation
large means wide range of different values and small means the values don’t differ very much
Frequency tables and histograms/barcharts help us to identify distributions and thus ____
puzzles
types of relationships to explore between categorical variables (nominal and ordinal)?
cross-tabulations and chi-square test
types of relationships between continuous variables
correlation
• Cross-tabulation displays the _____ frequencies and _____ frequencies of any two categorical (nominal or ordinal) variables
joint and relative
three steps to constructing a cross tabulation
- separate cases into groups based on independent variables
- compare groups and if they differ in anyway
- compare to what you expect to see
in a chi-square what must you firstly assume?
Assume the null hypothesis is true – that two variables are completely independent
if you get p>.05 from a chi-square test, you can or cant reject the null hypothesis?
you cant reject the null hypothesis. . The divergence wasn’t great enough to rule out the conclusion that the variables are completely independent.
if you get p
you can reject the null hypothesis and conclude that the relationship was statistically significant