Intro to statistics Flashcards
What are the 2 main types of data?
Nominal (qualitative)
Ordinal (quantitative)
What are the 2 types of Nominal/qualitative data? give examples
Unordered (e.g. male/female)
Ordered (e.g. small, medium, large)
What are the 2 types of ordinal/quantitative data? give examples
Discrete/whole numbers (e.g. students on the course, children in the family)
Continuous (e.g. weight in kg)
When analysing ordinal data, what are the 2 ways in which it can be analysed?
can be analysed by both, parametric or non-parametric tests
When would parametric and non-parametric tests be used to analyse data?
If the distribution is normal – use parametric test;
If the distribution is skewed – use a non-parametric test
Give Examples of non-parametric tests
Mann-Whitney, Wilcoxon, Kruskal-Wallis
Give Examples of Parametric tests
t-tests and Anova
What test is used to determine if there is a significant association between the two categorical variables(e.g., male/female voters vs voting preference (Labour, Conservative) ?
Chi2 (squared)
Define skewed distribution of data
Skewed distributions are asymmetrical and have data that clusters toward one end
How is normal distribution of data displayed ?
represents the distribution of many random variables as a symmetrical bell-shaped graph.
Define qualitative data
method of observation to gather non-numerical data.
Define quantitative data
measures of values or counts and are expressed as numbers
Define mean
the sum of all the samples, divided by the number of samples (n).
Define median
the value halfway through the ordered data set, below and above which there lies an equal number of data values.
Define quartile
Lower (first) quartile chosen to place 25% of the data below it, 75% above it
Upper (third) quartile chosen to place 75% of the data below it, 25% -above it