Stats definitions

Question 1

Qualitative data

Answer 1

non numerical data

Question 2

Quantitative data

Answer 2

numerical data

Question 3

continuous data

Answer 3

data that can take any value and range e.g time

Question 4

discrete data

Answer 4

-data that can only take certain values

Question 5

correlation

Answer 5

a measure of how closley 2 quantities are linearly related

Question 6

population

Answer 6

The whole set of items that are of interest

Question 7

census

Answer 7

Observes or measures every member of a population

Question 8

sample

Answer 8

Selection of observations taken from a subset of the population

Question 9

sampling unit

Answer 9

An individual item of a population

Question 10

sampling frame

Answer 10

A unique numbering or naming of sampling units to form a list

Question 11

simple random sampling

Answer 11

random sampling technique in which every member of the population has an equal chance of being selected

Question 12

systematic sampling

Answer 12

Random sampling technique in which elements are chosen at regular intervals from an ordered list

Question 13

stratified sampling

Answer 13

Random sampling technique in which the population is divided into mutually exclusive strata (classifications) and a random sample is chosen from each, maintaining the population’s proportions lying within each strata

Question 14

Quota sampling

Answer 14

Non-random sampling technique in which a sample is chosen by the researcher to represent the characteristics of the whole population

Question 15

Opportunity (convenience) sampling

Answer 15

Non-random sampling technique in which elements are selected based on availability at the time of sampling, chosen to fit required criteria.

Question 16

continuous variable

Answer 16

A variable that can take any value in a given range

Question 17

discrete variable

Answer 17

A variable that can take only specific values in a given range

Question 18

sample space

Answer 18

The set of all possible outcomes

Question 19

Probability distribution

Answer 19

A full description of the probabilities of any outcome in the sample space

Question 20

Test statistic

Answer 20

An observation or statistic calculated from a sample, used to test a hypothesis

Question 21

Actual significance level

Answer 21

The probability of incorrectly rejecting the null hypothesis (ie the chance that an observed result would fall in the critical region purely by chance if the model assumed by the null hypothesis were true).

Question 22

Binomial model

Answer 22

Where there are a fixed number of trials; exactly two possible outcomes; a fixed probability of success at each trial and trials are independent of each other

Question 23

Conditional probability

Answer 23

When the known occurrence of one event effects the probability of subsequent events.

Question 24

Critical region

Answer 24

A region of the probability distribution which, if the test statistic falls within it, leads to a rejection of the null hypothesis

Question 25

Hypothesis

Answer 25

A statement, which can be tested, about the value of a population parameter

Question 26

Normal distribution

Answer 26

A continuous probability distribution, which is symmetrical about the mean. It forms a bell shaped curve with points of inflection one standard deviation above and below the mean

Question 27

one-tailed / two-tailed test

Answer 27

A one-tailed test only has a critical region at one end of the distribution, whereas a two-tailed test has both extremes of the distribution included

Question 28

Parameter

Answer 28

A defining statistical characteristic of the population distribution

Question 29

Uniform distribution

Answer 29

Where the probability is the same for each outcome

Question 30

Hypothesis test

Answer 30

A statistical test that is used to determine whether there is enough evidence in a sample of data to infer that a certain condition is true for the entire population.