Introduction to Statistics PDF

Introduction of statistics Dr. Rehab Sabri Fawzi  Out line  Definitions of terms  Statistical Methods  Types of Statistics  Difference between descriptive and inferential studies. Statistics  Statistics simply means numerical data, and is field of math that...

Introduction of statistics Dr. Rehab Sabri Fawzi  Out line  Definitions of terms  Statistical Methods  Types of Statistics  Difference between descriptive and inferential studies. Statistics  Statistics simply means numerical data, and is field of math that generally deals with collection of data, tabulation, and interpretation of numerical data. It is actually a form of mathematical analysis that uses different quantitative models to produce a set of experimental data or studies of real life.  Definitions of terms:  Statistics is a tool that aids in organizing , summarizing and communicating f indings (data) clearly and meaning full.  Medical statistics/ Biostatistics is the science that applies the principles of statistics in the field of health  Data is the basic building blocks of statistics  Population and parameter  Population (N): is all elements (can be people or things)whose characteristics are being studied.  A value (average, total, etc.) that is calculated f ro m the entire population is called a Parameter.  Sample and statistic  A sample (n): is a subset of the population that is selected for study.  A value that is calculated from a sample is called a statistic.  Sample (n): consists of one or more observations from the population.  Subjects are the units on which characteristics are measured. In medicine and public health, the subjects are most frequently humans, but might also be cells in culture or animals used in research.  Statistical Methods A)Methods of data collection B) Analytic statistics C) Methods of data presentation  What is data?  Data are observations or evidences about the social world.  can be quantitative or qualitative in nature.  ‘Data are produced, not given; that is, researchers choose what to call data, it is not just ‘there’ to be ‘found’.  Data, information What is information? Information is data that have been processed to make them meaningful and useful. Data + Meaning = Information. For example, individual exam marks are raw data, but if you were to process those to say that boys did better than girls, or that 76% of the students in your school got a grade A or B, then that is information.  Source of data: Main source of demographic data: 1. Census 2. Vital registration 3. Official records 4. Simple survey 5. Individuals studied  Nature of Data The data can be classified into two broad categories : : Data Qualitative Quantitative Data Data or Variables or Attributes  Types of Statistics  Descriptive / Deductive  Inferential /inductive  Descriptive statistic  Techniques to organize, display, and describe data using tables, graphs, and summary measures.  Inferential statistics  Techniques that enable us to use information gathered from a sample to make decisions, inferences, or predictions about a population.  Statistic and Research  Statistics are used to analyze the data collected in a research study.  Example: Suppose research participants taste both Diet coke and diet Pepsi and indicate which one they prefer.  We have observed a difference (descriptive), but is this difference meaningful??.  Using statistics, we can determine if there is a meaningful difference between the number of people who preferer each soda! (Inferential). Descriptive Inferential  Calculations that describe data.  Calculations that determine whether differences between groups are due to chance or to the treatment  Highlight the most typical  Determines if results are values in a set of data. statistically significant  Example:  Examples: o Central tendency (mean, o T test median, mode) o Range o ANOVA o Stander deviation o Chi- Square o Correlation Types of Statistics :