Population – an entire set of individuals or items.
Finite Population – a population where each individual member can be given a number.
Infinite Population – a population where it is impossible to number each member.
Statistic – a random variable that is a function of known observations from a sample involving no unknown parameters.
Sampling Distribution – if all possible samples are taken, then the values of the statistics along with their associated probabilities will form a probability distribution called the sampling distribution.
Sampling Frame – a list of all the members of the population.
Sampling Unit – individual member or element of the population or sampling frame.
Census – when every member of the population is investigated.
Sample – a selection of items from the population that are used to represent the population.
Critical Region – the range of values of the test statistic that would lead you to incorrectly reject H0.
Level of Significance – the probability of incorrectly rejecting H0.
Hypothesis – a statement concerning a population parameter.
Hypothesis Test – A hypothesis test is a mathematical procedure to examine a value of a population parameter proposed by the null hypothesis H0 compared to the alternative hypothesis H1.
Test statistic – In a hypothesis test the evidence comes from a sample which is summarised in the form of a test statistic.
Critical Value – the boundary value of a critical region.
One tailed test – looks for an increase or decrease in a parameter and has one single critical value.
Two tailed test – looks for both an increase and a decrease in a parameter and has 2 critical values.
