Base of Quantitative Research

VariableHypothesisDifference

RelationshipBY M.SULEMAN TARIQ

Variable A variable is defined as a characteristic of

the participants or situation for a given study that has different values in that study

Morgan et. al (2004)

Base of Research => Variable Gender: Study 1: Variable Study 2: Constant

Hypothesis

Types of Hypothesis◦ Differential Hypothesis◦ Associational Hypothesis

Recommended Statistics for Different Types of Hypothesis

Types of Variable Dependant Variable Independent Variable

Mediating Variable

Moderating Variable

A B

A B

C

A B

C

Operationalization Operationalization is the process of defining

a concept so that it becomes measurable variable

Steps of Operationalization

8

Reliability Does the instrument measure things

consistently? Ways to establish reliability

◦ Test-retest◦ Internal consistency for multiple measures for the

same construct Cronbach’s alpha (Overall .70)

Reliability

.7 = Good .8 = Very good, strong .9 = or greater -> Excellent

Validity

Validity = does the test measure what its meant to measure?

Construct validity

Reliability vs. validity

Types of Variable - Scale in SPSS

Categorical Variable ◦ Nominal Variable ◦ Ordinal Variable

Scale Variable

Nominal Variable Gender

Ordinal Variable Conveys order

Scale Directly Measureable

◦ GPA, Age, Height, Weight, Temperature, Salary, Job Experience

Steps for Data Handling in SPSS

Instrument Development Complete Data Collection Coding Check and Correct Errors Define Variable Name Labeling Define Different Values Set Missing Value (if any) Data Entry Apply Test-Estimate the Model/Variables

Important ConceptsStatistics

Mean and Standard Deviation

The heights (at the shoulders) are: 600mm, 470mm, 170mm, 430mm and 300mm.

Standard Deviation

Normal Distribution of the data

Skewed Data

Correlation Correlation is Positive when the values increase together,

and Correlation is Negative when one value decreases as the

other increases