Hypotheses

9/4/2012

Readings

• Chapter 1 The Measurement of Concepts (14-23) (Pollock)

• Chapter 2 Measuring and Describing Variables (Pollock) (pp.28-31)

OPPORTUNITIES TO DISCUSS COURSE CONTENT

Office Hours For the Week

• When– Wednesday 11-1– Thursday 8-12– And by appointment

Course Learning Objectives

1. Students will learn the research methods commonly used in behavioral sciences and will be able to interpret and explain empirical data.

2. Students will learn the basics of research design and be able to critically analyze the advantages and disadvantages of different types of design.

VARIABLES

Turning things empirical

1. We experience it2. We Define it3. We give it value (operationalize)4. We develop a hypothesis to explain/predict

what we experienced in step 1

The Relationship Between them

UNITS OF ANALYSISHow we measure our Variables

Units of analysis

• The unit about which information is collected and that provides the basis of analysis

• Each member of a population is an element

• Why they are important?

Individual Unit

• The lowest form of data

• People, congressmen, presidents, etc

Aggregate Data

• A collection of individual level units

• Often measured in percentages

• Footprints

The Poor over Time

Immigration over time

The Problem of Access

FALLACIES MADE WITH DATA

Ecological Fallacy

• this arises when an aggregate/ecological level phenomenon is used to make inferences at the individual level.

• Taking statewide data and applying to individuals

• Does everyone in MS go to church?

The Exception Fallacy

• taking one person's behavior, attributes, etc and applying it to an entire group

• Using 1 example to define group behavior

Examples from Texas

HYPOTHESES

What Is a Hypothesis

• An educated Guess

• These are explicit Statements

• They Try to explain a relationship

• But they are only tentative until tested

The Null Hypothesis

• The Statement of No Relationship

• What we want to disprove

• The Basic start of research

H0

Correlative Hypothesis

• “there is a relationship between x and y”

• A very weak statement

Positive Hypothesis

• A directional hypothesis

• “as the independent variable increases, the dependent variable increases”

Positive Relationship

Negative Relationship/Hypothesis

• “As the independent variable increases, the dependent variable decreases”

• Also called an inverse hypothesis

An Example

Logarithmic

• Y=log(x)

• The dependent variable changes rapidly, followed by less change

An Example

Curvilinear

• The Relationship forms a curve!

• The dependent variable increases to a point, and which point it begins to decrease

The Laffer Curve

• The Debate over taxes• Ben Stein

Fuel Efficiency

Hulk Hogan

• Roddy Piper (4:44)

• King Kong Bundy (2:56)

More

Stating a hypothesis

There is a _____(direction)________relationship

between ________and ____________

CHARACTERISTICS OF GOOD HYPOTHESES

Good Hypotheses are Empirical

• Something that we can Measure

Good Hypothesis are

Generalizable• Apply to more than one

case

Specific• Always State a direction

• Always identify the iv and the d.v.

• Avoid the correlative hypothesis

Good Hypotheses are Plausible

• There needs to be a Real world justification for why they are related

• If Chewbacca lives on Endor, you must acquit

Good Hypotheses are Testable

• You have to be able to test your hypothesis or it is just speculation.

Non-Tautological

• Your independent and dependent variables are separate concepts

A CAUSAL HYPOTHESISA Test of Scientific Knowledge

What is a causal hypothesis?

• The Boldest Hypothesis out there

• A relationship that will occur 100% at all times, no exceptions

• Difficult to Prove

To Prove a Causal Hypothesis

1. A Change in the Independent Variable will always cause a change in the dependent variable.

2. A change in X always precedes a change in Y

3. X is necessary and sufficient to cause a change in Y

Causality is the heart of scientific knowledge!