Introduction to Biostatics. Shahzad Bashir RN, BScN. 1
ELEMENTARY STATISTICS MARIO F. TRIOLA EIGHTH EDITION 2
ELEMENTARY STATISTICS Chapter 1 Introduction to Statistics MARIO F. TRIOLA EIGHTH EDITION 3
Introduction to Statistics Objectives. Define statistics. Describe the Characteristics of Statistics. Discuss the Concept of Biostatistics. Explain the Classification of Biostatistics. Define Variable. Classification of Variable.. 4
Definition. Definition of Statistics: Statistics is the study of methods and procedure for collection, classification, analysis and interpretation of data. The term has been described from the Latin word Status the Italian word Statistica and the German word Statistik these words mean political state or a Govt. 5
Characteristics of Statistics. Statistics is the aggregate of fact. Statistics are always expressed numerically. Statistics is influenced by causes. Statistics data need to be collected in a systemic manner. Statistics data is collected for predetermined purposes. 6
Biostatistics. Bios Statistics is the application of statistical methods to the problems of biology, including human biology, medicine and public health. Statistical methods include the collection, organization, classification, analyzation and measure evaluation of facts to reach some inferences. 7
Biostatistics. Biostatistics is also called Biometry. The word Biometry is a Greek word Bio means Life and metron mean measurement. 8
Classification of Biostatistics. Classified into TWO types: Descriptive biostatistics: Includes Collection, organization, summarization and presenting of data. Inferential Biostatistics: Includes Making inferences, Hypothesis testing, Determing relationship, and making prediction. 9
Overview Statistics Two Meanings Specific numbers Method of analysis 10
Statistics Specific number numerical measurement determined by a set of data Example: Twenty-three percent of people polled believed that there are too many polls. 11
Statistics Method of analysis a collection of methods for planning experiments, obtaining data, and then then organizing, summarizing, presenting, analyzing, interpreting, and drawing conclusions based on the data 12
Definitions Population the complete collection of all elements (scores, people, measurements, and so on) to be studied. The collection is complete in the sense that it includes all subjects to be studied. 13
Definitions Census the collection of data from every element in a population Sample a subcollection of elements drawn from a population 14
Definitions Parameter a numerical measurement describing some characteristic of a population 15
Definitions Parameter a numerical measurement describing some characteristic of a population population parameter 16
Definitions Statistic a numerical measurement describing some characteristic of a sample 17
Definitions Statistic a numerical measurement describing some characteristic of a sample sample statistic 18
Variable. Variable is a quantity which can vary from one individual to another. For example animals of same species may differ in their weight, age, sex, etc. These characteristics are variables. Thus Variables can be define as: The characteristics by which individuals differ among themselves. 19
Classification of Variable. Variable is Classified into Two types: Quantitative Variable.(Numerical) Qualitative Variable.(Categorical) 20
Classification of Variable. Quantitative Variable: It is also called Numerical Variable. Name indicate that it contains numerical data. Further divided into two types: 1. Discrete: E.g. No. of Births, Accidents, Price of eggs. 2. Continuous: Height, Temperature, Age, B.P, Incomeetc. 21
Classification of Variable. Qualitative: Also called Categorical. Specific heading is given into number of observation data. It is further divided into two types: 1. Nominal: (Can be arranged in some order) E.g. Sex, Marital Status. 2.Ordinal: ( Increase or Dec. order is arranged) E.g. Level of knowledge, Good, Average, Poor opinion, Fully agree etc. 22
Definitions Quantitative data numbers representing counts or measurements 23
Definitions Quantitative data numbers representing counts or measurements Qualitative (or categorical or attribute) data can be separated into different categories that are distinguished by some nonnumeric characteristics 24
Definitions Quantitative data the incomes of college graduates 25
Definitions Quantitative data the incomes of college graduates Qualitative (or categorical or attribute) data the genders (male/female) of college graduates 26
Definitions Discrete data result when the number of possible values is either a finite number or a countable number of possible values 0, 1, 2, 3,... 27
Definitions Discrete data result when the number of possible values is either a finite number or a countable number of possible values Continuous 0, 1, 2, 3,... (numerical) data result from infinitely many possible values that correspond to some continuous scale that covers a range of values without gaps, interruptions, or jumps 2 3 28
Definitions Discrete The number of eggs that hens lay; for example, 3 eggs a day. 29
Definitions Discrete The number of eggs that hens lay; for example, 3 eggs a day. Continuous The amounts of milk that cows produce; for example, 2.343115 gallons a day. 30
Definitions nominal level of measurement characterized by data that consist of names, labels, or categories only. The data cannot be arranged in an ordering scheme (such as low to high) Example: survey responses yes, no, undecided 31
Definitions ordinal level of measurement involves data that may be arranged in some order, but differences between data values either cannot be determined or are meaningless Example: Course grades A, B, C, D, or F 32
Definitions interval level of measurement like the ordinal level, with the additional property that the difference between any two data values is meaningful. However, there is no natural zero starting point (where none of the quantity is present) Example: Years 1000, 2000, 1776, and 1492 33
Definitions ratio level of measurement the interval level modified to include the natural zero starting point (where zero indicates that none of the quantity is present). For values at this level, differences and ratios are meaningful. Example: Prices of college textbooks 34
Levels of Measurement Nominal - categories only Ordinal - categories with some order Interval - differences but no natural starting point Ratio - differences and a natural starting point 35
Levels of Measurement Nominal - categories only Ordinal - categories with some order Interval - differences but no natural starting point Ratio - differences and a natural starting point 36
END ANY Question. 37