Research Design

What is Research Design ? Plan for getting from the research question

to the conclusion Blueprint for data collection and

interpretation Deals with the logic of scientific inquiry A strategy for testing hypothesis Interpretative work Understanding phenomenon A plan for conducting scientific research for

the purpose of learning about a phenomenon of interest

What is Research Design ? Overall plan or framework for the

investigation, anticipate all of the subsequent stages of the research process.

Decision also be made for: Selecting unit of analysis Selecting variable to observed and controlled How to measured variables How to analyze of data

Good Research Design should rule-out alternative explanations

Alternative Explanations

Asian financial crisis in the late 1990’s Institutional weaknesses (lack of

transparency in corporate and political governance) -> cronyism

Market failure with under-regulation of financial market

Unit of Analysis The entity about whom or which the

researcher gathers information. The unit is simply what or who to be

described or analyzed Examples of unit:

Individuals Groups Artifacts (books, photos, newspapers) Geographical units (town, census tract, state) Social interactions (dyadic relations, divorces,

arrests)

Units of Analysis Examples If you are comparing the children in two

classrooms on achievement test scores, the unit is the individual child because you have a score for each child.

On the other hand, if you are comparing the two classes on classroom climate, your unit of analysis is the group, in this case the classroom, because you only have a classroom climate score for the class as a whole and not for each individual student.

Units of Analysis Examples (2)

If the researcher wanted to know what kind of people are attracted to the field of computer science, the unit is individual people

If the researcher wanting to determine if larger organization have more bureaucratic rules and regulations, the unit is organization

Hierarchical Modeling The incorporation of multiple units of analysis

within a single analytic model Aggregation in the analysis Analyze individual person using aggregate data to

characterize the groups or collectivities to which the individuals belong.

For instance, in an educational study, you might want to compare student performance with teacher expectations. To examine this relationship would require averaging student performance for each class because each teacher has multiple students and you are collecting data at both the teacher and student level.

Fallacy

An error in reasoning, usually based on mistaken assumptions. Ecological fallacy Exception falalcy

Ecological Fallacy Occurs when you make conclusions about

individuals based only on analyses of group data. For instance, assume that you measured the

math scores of a particular classroom and found that they had the highest average score in the district. Later (probably at the mall) you run into one of the kids from that class and you think to yourself, 'She must be a math whiz.' Aha! Fallacy! Just because she comes from the class with the highest average doesn't mean that she is automatically a high-scorer in math. She could be the lowest math scorer in a class that otherwise consists of math geniuses.

Exception fallacy Sort of the reverse of the ecological

fallacy. It occurs when you reach a group

conclusion on the basis of exceptional cases.

The stereotype is of the guy who sees a woman make a driving error and concludes that women are terrible drivers. Wrong! Fallacy!

Variables Any entity that can take on different values Characteristics of units that vary, taking on

different values, categories, or attributes for different observations

May vary over cases, over time or over both cases and time

Example: Age (range of years) Gender (female & male) Marital status (single, married, divorced, widowed, etc) Level of education (primary, secondary, diploma, etc)

Types of variables Explanatory

Dependent variables Independent variables Antecedent variables Intervening variables

Extraneous Controlled Uncontrollled

Qualitative & Quantitative

Dependent-Independent Dependent is variables that the researcher

interested in explaining or describing Independent is the explanatory variables that

do the influencing and explaining, also called predictor variable

In terms of cause and effect, the independent variable is the presumed cause and the dependent variable is the presumed effect

For example: when the relationship between educational attainment (years of schooling) and income is studied, educational attainment is the IV and income is DV

Antecedent & intervening Antecedent variable

occurs prior in time to both the independent and dependent variable

Intervening variable occurs if it is an effect of the independent variable and a cause of the dependent variable

Parent’s income(antecedent)

Type of school (independent)

Academic achievement(dependent)

Amount of homework(intervening)

Type of school (independent)

Academic achievement(dependent)

Quantitative & Qualitative A variable is quantitative if its value or

categories consist of numbers and if differences between its categories can be expressed numerically Income

Qualitative variables have discrete categories, usually designated by words or labels, and nonnumerical differences between categories Gender male & female

RQ, Unit analysis and variables

Research Question/Hypothesis

Unit of Analysis Variables

[What ones to know][What entities are described and compared]

[With respect to what characteristics]

Are older people more afraid of crime than younger people ?

Individuals age, fear of crime

Does economic development lower the birth rate ?

nationslevel of economic development, birth rate

The longer the engagement period, the longer the marriage

coupleslength of engagement, marriage duration

a student's grade-point average is directly related to his or her class attendance

Individualsgrade-point average, attendance record

Relationship Types of relationship:

Among Qualitative variables Among Quantitative variables Between Qualitative and Quantitative variables

Properties of relationship: The extent of to which variables are associated

or correlated Strength

How changes in one variable are related to changes in another

Directionality Linearity

Relationship among qualitative variables

Relationship among quantitative variables

Direction and linearity Direction positive vs negative Linearity linear vs curvilinear

A positive (direct relationship) between variables exists if an increase in the value of one variable is accompanied by an increase in the value of the other, or if a decrease in the value of one variable is accompanied by a decrease in the value of the other.

Sons’ heights and fathers’ heights (the taller the father, the taller the son will tend to be)

A negative (inverse relationship) between variables exists if a decrease in the value of one variable is accompanied by increase in the value of the other.

Speed and accuracy (the faster one does something, the less accuracy one is likely to do it)

Relationship among quantitative variables (2)

Relationship between qualitative and quantitative variables