Introduction to Statistics

Introduction to Statistics

• Statistics is a process of collecting, organizing, and analyzing data set variables
• Biostatistics focuses on data related to living things

The Role of Statistics

• Statistics are built upon concepts, rules, and procedures
• Statistics organizes numerical information into data tables, graphs, and charts
• Statistical techniques are used to make more informed decisions that affect lives
• Data exists on productivity, economic growth, exchange rates, interest rates, company profits, imports, and exports
• Statistics converts data into useful information using scientific procedures and methods, which can then be used for data collection and summarizing data

Statistical Procedures and Methods

• Forming a hypothesis
• Research design
• Data collection
• Summarizing data
• Making inferences/conclusions
• Writing reports

Types of Statistical Analysis

• Descriptive analysis compiles, organizes, summarizes, and presents data in visual forms that are easy to understand and use
• Descriptive analysis often uses tables, graphs, charts, and diagrams to present information
• Raw data is transformed into meaningful forms for generalizations or conclusions
• Inferential analysis draws conclusions or inferences from a sample
• A sample is to select a sample from a population, measure variables, analyses data, interpret output, and conclude

Key Terms in Statistics

• Population
• Sample
• Variable
• Parameter
• Census
• Pilot study

Population

• A population is an entire collection of objects that are of interest to study
• This could include people, animals, and plants
• Examples of populations include all MS students, public in KL, teenagers in Malacca, and all students in Johor

Sample

• A sample designates a subset of items chosen from a population
• Populations are often too large to study in their entirety, therefore, a sample is appropriate
• For example, a sample of all MS students might be 250 students out of 500 total
• A sample of the public in KL could be 500,000 out of 1.3 million
• In Malacca, a sample of teenagers could be 300,00 out of 1.5 million

Variable

• A variable is a particular characteristic of an object that is being studied
• This characteristic can take on different values when measured or gathered from one object to another
• Examples include height, weight, blood type, and parent's income

Numerical Parameters

• Categorical
• Ordinal
• Nominal
• Discrete
• Continuous

Parameter

• A parameter is a singular value used to represent a certain characteristic
• A parameter is a summary measure for an entire population
• Parameters can be thought of as standards, such as normal blood pressure
• In a country of 10 million students, the mean English oral score of all 10 million students is 60, if this is found, it is referred to as a population parameter

Census

• A census collects data from every unit in a population
• They are typically performed by government agencies, given the large population sizes
• The costs and labor of collecting census data are very high
• Many countries carry out a census study of their population every ten years to update residents' information
• It can be possible to obtain census data on all the fisherman in a small fishing village to study monthly income

Pilot Study

• A pilot study is done before actual fieldwork begins
• The aim is to identify possible problems and difficulties that may occur during the actual study
• Pilot studies can test out questionnaires and improve their flow, question design, language, and clarity

SPSS

• SPSS is statistical analysis software
• SPSS is a statistical package for social sciences
• SPSS can assist in data entry, data cleaning, and data analysis