Research Questions, Hypotheses, and Variables

Choosing a Research QuestionSpecifying an Explanation

Hypotheses

The Research ProcessDefine and Refine

Research QuestionLocate ResearchCollect Important

InformationWrite the

Literature ReviewMake Me Proud

Choosing a Research QuestionConcerned with the initial steps of an

empirical research projectFirst step is to choose a research question

Choosing a Research QuestionPolitical scientists investigate diverse

phenomena.Research question may focus on

The political behavior of individuals, groups, institutions, or political jurisdictions

Descriptive, factual, or normative knowledgeTwo or more variables

Choosing a Research QuestionResearch questions may originate from

Personal observation or experienceWritings of othersInterest in some broader social theoryPractical concerns like career objectives

Central Research Question

Define Your Research Question-What are you researching?-What do you seek to accomplish?

Refine Your Research Question-Is your question too broad? Too vague?-Is there an abundance of information?-Too much information? Too Little?

Specifying an ExplanationHow are two or more variables related?

A variable is a concept with variation. An independent variable is thought to

influence, affect, or cause variation in another variable.

A dependent variable is thought to depend upon or be caused by variation in an independent variable.

Specifying an ExplanationVariables can have many different kinds of

relationships:Multiple independent variables usually neededAntecedent variablesIntervening variablesAn arrow diagram can map the relationships

Quantitative ResearchVariables

(Attributes)Independent

VariableDependent VariableControl VariableHypotheses (not to

be proven!)Null Hypotheses

Specifying an ExplanationCausal relationships are the most interesting.A causal relationhip has three components:

X and Y covary.The change in X precedes the change in Y.Covariation between X and Y is not a

coincidence or spurious.We can state relationships in hypotheses.

HypothesesSix characteristics of a good hypothesis:

1. Should be an empirical statement that formalizes an educated guess about a phenomenon that exists in the political world

2. Should explain general rather than particular phenomena

3. Logical reason for thinking that the hypothesis might be confirmed by the data

4. Should state the direction of the relationship5. Terms describing concepts should be

consistent with the manner of testing6. Data should be feasible to obtain and would

indicate if the hypothesis is defensible

The Hypothesis

Makes a predictionMost research questions, however, formulate

more than one hypothesis. Attendance, along with solid study habits and

ample rest could also influence course grades.

Yet, the focus is typically on the null hypothesis.

Null HypothesisA hypothesis of no

relationshipProve or disprove

the null hypothesis to show support or opposition to your actual hypothesis.

Why?

HypothesesHypotheses must specify a unit of analysis:

Individuals, groups, states, organizations, etc…Most research uses hypotheses with one unit

of analysis.Need to be able to identify these to be

successful

Clarity In Research

Be precise in determining unit(s) of analysis.

How will you analyze? Why are you choosing to analyze this way?

Choose the proper level of analysis.

Ecological FallacyA higher level of

data trying to explain a lower level of behavior.

Too much generalizing.

Ex: Income level in a community

ReductionismA smaller level of

data trying to explain a higher level of behavior.

Ex: Steve Bartman caused the Chicago Cubs to miss the World Series in 2003.

SpuriousnessA false

relationship; a relationship that appears but is not.

Other factors often enter

Ex: Children who listen to classical music perform better in school.

HypothesesDefinitions of concepts should be

ClearAccuratePreciseInformative

Otherwise, reader will not understand concept correctly.

Many of the concepts used in political science are fairly abstract—careful consideration is necessary.

What is a Variable?Simply, something that varies.Specifically, variables represent persons or

objects that can be manipulated, controlled, or merely measured for the sake of research.

Variation: How much a variable varies. Those with little variation are called constants.

Examples of VariablesIn the recent GOP

sweep of the House and Senate, variables (or factors) that may have played a part would include:

Voter TurnoutParty Message# of Open SeatsRedistricting# of IncumbentsWellstone Funeral

Independent VariablesThese variables are ones that are more or

less controlled. Scientists manipulate these variables as they

see fit.They still vary, but the variation is relatively known or taken into account.

Often there are many in a given study.

Dependent VariablesDependent variables are not controlled or

manipulated in any way, but instead are simply measured or registered.

These vary in relation to the independent variables, and while results can be predicted, the data is always measured.

There can be any number of dependent variables, but usually there is one to isolate reason for variation.

Independent V. DependentIntentionally

manipulatedControlledVary at known rateCause

Intentionally left aloneMeasuredVary at unknown rateEffect

Example: What affects a student’s arrival to class?Variables:Type of School

Liberals Arts v. UniversityType of Student

Athlete? Gender? GPA?Time

Bedtime, Waking, ArrivalMode of Transportation

Variables

The Independent Variable (IV) causes (causal relationship) the Dependent Variable (DV).

Example:Students who attend class earn higher course

grades.IV: Class attendanceDV: Course grades

ExampleAn investigator had 60 subjects watch a

videotaped re-enactment of a bank robbery.   Half of the subjects were asked by a police investigator to recall the event, while the remaining subjects were interviewed by a police investigator while they were hypnotized.

Independent Variable: 

Dependent Variable:

Example 2To test a new voice feature in a cockpit design a flight

simulator was used.  The simulator was programmed to give visual readings of flight information, or to give visual and auditory (voice) readings of flight information.  All test pilots were put through a simulated emergency landing procedure, but were randomly assigned to the visual, or visual and auditory conditions.  Flight experts rated each pilot’s performance in the simulator on a scale of 1 (very poor) to 10 (excellent). 

Independent Variable:

Dependent Variable: