Statistics
Worksheet 1 - Basic Concepts 1. What is Inferential statistics?
Inferential statistics uses observations of past occurrences or available data i.e. descriptive statistics to make decisions about future possibilities and/or the nature of the entire body of data. Inferential statistics draws conclusions or makes interpretations, predictions and inferences about a population based upon an analysis of a sample. 2. Give 2 different techniques which are used in descriptive statistics to represent the data.
Tables or graphs (histograms, boxplots, etc) or numerical summaries 3. Define each of the following terms: a) Variable
The topics/issues under investigation in statistical analysis. The variable is a characteristic or property of the members of the population which may vary e.g. height, weight, perception etc. b) Population
The total group about which information is being sought. If information is sought about voting intentions, the population is all those people eligible to vote in an electorate, or a state or the nation. c) Sample
A sample is a group taken from the population. Most statistical situations do not allow an entire population to be used for analysis (usually because it is too large, the geographical dispersion of subjects, logistical issues, funding, time restraints etc) so a sample must be used. The sample chosen should be representative of and reflect all of the characteristics of the population.
4. What is the difference between a sample and a random sample?
A sample is any subset of individuals taken from a population, and there are many types of sampling strategies (to be covered in the next few weeks). A random sample is the objective of all good research studies; to design a sampling strategy with the objective of reducing and/or eliminating bias. 5. What are the four levels of measurement and give an example of each?
Qualitative Nominal – Gender, Qualitative Ordinal – Star rating on a hotel, Quantitative
Inferential statistics uses observations of past occurrences or available data i.e. descriptive statistics to make decisions about future possibilities and/or the nature of the entire body of data. Inferential statistics draws conclusions or makes interpretations, predictions and inferences about a population based upon an analysis of a sample. 2. Give 2 different techniques which are used in descriptive statistics to represent the data.
Tables or graphs (histograms, boxplots, etc) or numerical summaries 3. Define each of the following terms: a) Variable
The topics/issues under investigation in statistical analysis. The variable is a characteristic or property of the members of the population which may vary e.g. height, weight, perception etc. b) Population
The total group about which information is being sought. If information is sought about voting intentions, the population is all those people eligible to vote in an electorate, or a state or the nation. c) Sample
A sample is a group taken from the population. Most statistical situations do not allow an entire population to be used for analysis (usually because it is too large, the geographical dispersion of subjects, logistical issues, funding, time restraints etc) so a sample must be used. The sample chosen should be representative of and reflect all of the characteristics of the population.
4. What is the difference between a sample and a random sample?
A sample is any subset of individuals taken from a population, and there are many types of sampling strategies (to be covered in the next few weeks). A random sample is the objective of all good research studies; to design a sampling strategy with the objective of reducing and/or eliminating bias. 5. What are the four levels of measurement and give an example of each?
Qualitative Nominal – Gender, Qualitative Ordinal – Star rating on a hotel, Quantitative