introduction Statistics.pdf introduction to the statistics
- 1. ž Derived from latin word “status” ž Status means information useful to state ž Backbone of research ž Facts systematically arranged e.g Statistics of birth, statistics of road accidents, statistics of educational institutions
- 2. It is a branch of science that deals with collection of data, presentation of data ,making analysis and drawing conclusion to reach decisions in the face of uncertainty. Data…….collection of values
- 3. ž Assists in summarizing the larger sets of data in a form that is easily understandable ž Assist in effective planning in any field of inquiry ž Drawing conclusions and making predictions ž Useful tool in aiding researches and studies in different field ž Presentation of organized data in charts and graphs
- 4. ž Biostatistics ž Econometrics ž Psychometry ž Geostatistics ž Environmental statistics ž Actuarial statistics
- 5. • Statisticians often use the method of comparison. • We want to know the effect of a treatment (like the Salk vaccine) on a response (like getting polio). • Compare the responses of a treatment group with a control group
- 6. The population consists of the set of all measurements in which the investigator is interested.The population is also called the universe E.g Population of patients Population of smokers Population of cancer patients
- 7. Sample is a representative part of the population ž Usually populations are so large that a researcher cannot examine the entire group. Therefore, a sample is selected to represent the population in a research study. The goal is to use the results obtained from the sample to help answer questions about the population.
- 8. ž Parameter is any numerical value calculated from population. It is denoted by Greek letter ž Statistic is any numerical quantity calculated from sample. It is denoted by Roman letter
- 9. ž Descriptive statistics ž Inferential statistics
- 10. ž Descriptive statistics are methods which deals with collection of data, presentation of data in different forms e.g tables, graphs and diagrams and finding averages and other measures which would describe the data. ž For example, tables or graphs are used to organize data, and descriptive values such as the average score are used to summarize data.
- 11. It deals with the procedures for making inferences about the characteristics of population based on the characteristics of sample.
- 12. ž Variables are things that we measure, control, or manipulate in research.They differ in many respects ž Variables are characteristics which takes different values in different situations. ž Height, marital status, no of visits to hospital ,blood pressure
- 13. A constant is a characteristic that does not vary. A constant also is a symbol, often a letter toward the beginning of the alphabet, such as a, b, or c.
- 14. Discrete variable ž Capable of taking some specific numerical values in a given range E.g no of successful operations in a hospital No of heart beats in a fixed period of time
- 15. ž It is capable of taking each and every possible value with in a given range. ž E.g ž Age , weight , length
- 16. ž Qualitative data When a population is classified into several categories, it is possible to count the number of individuals in each category. These counts are the qualitative data. e.g Gender, hair color, blood types
- 17. ž Observations which are measured quantitatively give rise to quantitative data. E.g Cholesterol level, blood pressure
- 18. ž Primary data The data that is originally collected and have not undergone any sort of statistical treatments ž Secondary data The data that have undergone any sort of statistical treatment atleast once.