Statistics - Two
- 1. Introduction to Statistics Ms. Carter
- 2. What is statistics? Statistics is a discipline which is concerned with: designing experiments and other data collection, summarizing information to aid understanding, drawing conclusions from data, and estimating the present or predicting the future.
- 3. Data: Pieces of numerical and other information. Maybe an easier definition of data is ‘a series of facts from which conclusions may be drawn”.
- 4. Statistics in Today’s Society Who uses statistics and why?
- 5. Statistics can be either.. These are numbers that are used to consolidate a large amount of information permit the researcher to demonstrate the probability that the results deriving from a sample are likely to be found in the population from which the sample has been drawn. Descriptive Inferential
- 6. An unordered list is called DATA. When the list is ordered in some way, it becomes INFORMATION.
- 7. Types of Data Category (Where Q’s cannot be answered with no’s! E.g. Haircolour) Numeric (Q’s that can be answered with no’s!) Nominal (can’t be ordered) Ordered (in some way e.g exam grades) Discrete (no. or measurement that are only certain no e.g. shoe size) Continuous (E.g. height as changes in relation to age)
- 8. Populations and Samples A population is the entire group that is being studied. A sample is a group that is selected from the population. NOTE: Unrepresentative samples give biased results. Bias is a distortion of the results.
- 9. When choosing a sample, you should always ensure that: - The sample is large enough. - A random sample is chosen from the population. - Everybody has an equal chance of being selected. Reliability of Data
- 10. Primary and Secondary Data Primary Data: collected by or for the person who is going to use it. 1. Experiments 2.Surveys Secondary Data: NOT collected by or for the person who is going to use it e.g. Guinness Book of Records