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STATISTICS FOR EDUCATIONAL RESEARCH

TOPIC 1: INTRODUCTION

What is statistics?

is a branch of mathematics dealing with the collection, organizing, analysis, interpretation &presentation of masses of numerical data.

=>meaningful conclusions can be drawn from them.Types of Statistics?

Two kinds of Statistics

Descriptive statistics Inferential statistics

Whats the DIFFERENCE?

Descriptive Statistics

Techniques that take the raw scores from a distribution and summarize them in a form that is moremanageable.

characteristics of the data = described in simple terms. Methods = summarize, organize, simplify data. Include the construction of graphs, charts & tables and the calculation of various descriptive

measures such as average (MEANS) and measure of variation (STANDARD DEVIATION).

Inferential Statistics

Other name = statistical induction. Comprises the use of statistics to make inferences concerning some unknown aspect of a

population.

mathematical tools to make forecasts and projections by analyzing the given data.When use the statistics??

Descriptive statistics To describe the basic features of the data in a study. To present quantitative descriptions in a manageable form.

Inferential statistics To study samples and then make generalizations about the population from which they

were selected

Interrelation between Descriptive statistics & Inferential statistics

Preliminary descriptive analysis of sample > choose the appropriate inferential method. Descriptive Statistics =

performed on a sample & on a population To examine & explore the data

Inferential Statistics = An inference is made about the population based on the samples data

VARIABLES AND DATA SETS

A variable is property of an object or event that can take on different values. It is a characteristic associated

with each unit in a population

Constant: An event whose value never changes

Quantitative data can be distinguished in terms they are discrete or continuous.

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Discrete vs Continuous variable

A discrete variable (also called a count variable)

is a numerical variable whose values are obtained from a count.

Continuous Variable A variable that consists of numbers whose values, at least in theory has no restrictions. Example, weights of female statistics students, reaction time, standardized test score

Continuous or Discrete??

Cooking time for pasta IQ score Age Population in Parit Raja Number of speeding tickets obtained Speed of jetliner.

Data

Quantitative Data Qualitative Data

Quantitative Data

Data is quantitative if the observations or measurements made on a given variable of a sample orpopulation have numerical values.

Example: height, weight, number of children, blood pressure, current, voltage. is discrete if the corresponding data values take discrete values.

Example : number of children, number of cars. is continuous if the data values take continuous values.

Example: speed, distance, time, pressure.Qualitative Data

Data is qualitative if words, groups and categories represents the observations or measurements. Example: colors, yes-no answers, blood group.

Qualitative or Quantitative ?

Race Age Family size Academic major IQ Score

Net Worth (RM) Favorite sport Gender Temperature Political preference

Data Types/ Measurement Scales

Nominal Ordinal Interval Ratio

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