Agenda: Research DesignAgenda: Research Design

Experimental

Non-experimental

Quasi-experimental

Quantitative and Qualitative research

Experimental ResearchExperimental Research

ExampleExample

Objective: To find out the impact of sunshine on plants’ growth.

Treatment

Experimental Control

I.V.I.V.

Experimental designExperimental design

Sample: low birth weight infants that were in intensive care & their moms, from same hospital

Randomly assigned to treatment or control group Treatment: Training program to help them cope

w/ special needs of low birth wt infant I.V. Level 1 -- training. Level 2 -- no training D.V. Mom’s self-confidence, perception of

infant’s temperament, satisfaction w being mom

Experimental ResearchExperimental Research

Researchers manipulate independent variable - 2 levels

And measure the other (dependent variable) Give treatment to participants and observe if it

causes changes in behavior

Compare experimental group (w/ treatment) with a control group (no treatment)

Can say IV caused change in the DV

Experimental research designExperimental research design

Measure dependent variable Control extraneous variables

Hold constant The only difference between experimental

group and control group is the manipulated variable.

Treat groups equally except for treatment.

Randomize effects across treatments Design to eliminate alternative explanations

Random Assignment

A way to assign participants in your sample to the various treatment conditions (groups that will receive different level of the IV)

Any member of your sample has equal chance of being assigned in any treatment group

Quasi-experimental researchQuasi-experimental research

Naturally occurring conditions (IV change) No control over variables influencing

behavior (confounding variables) Another variable that changed along with the

variable of interest may have caused the observed effect

Variables that affect decision to offer helpVariables that affect decision to offer help

Field experiment - Philadelphia subway Hypoth: Person’s assessment of “cost” of helping

affected decision to help IV Perceived costs to helper were manipulated 1 - confederate fell down in subway car (no blood) 2 - confederate fell down in subway car and bit on

vial of theatrical blood (bloody) DV - Researcher measured the time it took before

someone helped Finding: help given faster when victim ________

Field experiment Field experiment - nursing home residents - nursing home residents

Independent variable: Degree of control over decisions that affect their lives

Group 1: were given responsibility/ control for making choices about home’s operation

Group 2: the staff would be responsible for their care and needs

Dependent variables: Activity level, happiness, physical health

Program evaluationProgram evaluation

Research on programs that are proposed and implemented to achieve

some positive effect on a group of individuals Outcome evaluation

Did the program result in the positive outcome for which it was designed?

Process evaluation Is program reaching target population, and

attracting enough clients? Is staff providing the planned services?

Non-equivalent control group Non-equivalent control group pre-test -- post-test pre-test -- post-test designdesign

Dependent Dependent

Variable Variable

Pre-test Post-test

Group 1 Measure Treatment Measure

Grp. 2 Measure No Treatment Measure Control

Research DesignResearch Design

Between subjects / independent groups Compare 2 separate groups

Within subjects / repeated measures Same participants experience both levels of IV

First IV level 1, followed by measure of DV. Then IV level 2, followed by measure of DV

Number of observations Timing of treatment (pre, post)

Key factors in research designKey factors in research design

Manipulate variable / Treatment Control of variables Control or comparison groups Assignment of groups to “treatment

conditions” Quantitative or Qualitative

Non-Experimental ResearchNon-Experimental Research

Why use non-experimental Why use non-experimental correlational researchcorrelational research

Gathering data in early stages of research

Inability to manipulate variables

How naturally occurring variables relate in “real world”

Non-experimentalNon-experimental Correlational research Correlational research

Determine whether 2 or more variables are associated,

If so, to establish direction and strength of relationships

Observe variables as they are, can’t manipulate them

Correlational researchCorrelational research Interested in

Variable: # of gifts bought by college students Variable: time of semester -- early, middle, or late

Finding: Students more likely to purchase gifts at end of semester. These 2 variables are related.

Does end of semester cause more gift buying? Could be a 3rd variable (not measured) causing

the effect. If this is Fall semester project, what is likely the

3rd variable?

Causal - (Experimental) one variable directly or indirectly influences

another.

Correlational - (Non-experimental) Changes in one variable accompany

changes in another. A relationship exists. Don’t know if either

variable actually influences the other.

Non-Experimental ResearchNon-Experimental Research Researchers observe participants in

natural settings and describe them

Non-experimental Correlational

Experimental Causal Comparative

Descriptive

High LowCausality

Research designResearch design

Manipulate IV Random Assignment

Experimental (Causal) x x Quasi-experimental x

Non-experimental / Correlational

Predictive Descriptive

Experimental vs. Non-ExperimentalExperimental vs. Non-ExperimentalExperimental Non-

Experimental

Control?High Low

Causality?Strong Weak

Describe Reality?

Weak Strong

ApproachDeductive Inductive

Quantitative Research Quantitative Research vs.vs.Qualitative ResearchQualitative Research

Quantitative vs. Qualitative Quantitative vs. Qualitative ResearchResearch

Quantitative Research presents the results as quantities and numbers (i.e., statistics)

Qualitative Research presents results in words (e.g., quotations, descriptions)

Quantitative vs. QualitativeQuantitative vs. Qualitative

Quantitative Qualitative

Survey

Closed-end Open-end

Interviews

Structured Unstructured

Case Study

Field Work

Quantitative vs. QualitativeQuantitative vs. Qualitative

Quantitative Qualitative

Generalizablity?High Low

Flexibility?Low High

Systematic?Strong Weak

In-Depth?Weak Strong

ApproachDeductive Inductive

Select Select Quantitative or QualitativeQuantitative or Qualitative

Based on… The purpose of research or Research question

What’s already known about the topic The level of sensitivity (topic or participant) Availability of participants Availability of resources (time & budget) Needs of the audience

Homework 3) Homework 3) Literature review: Summary Literature review: Summary of two articles (Part I)of two articles (Part I)

Due: Feb. 4 (Feb. 6 is OK) Each student - write short summary of 2

scholarly journal articles about a research study)

This info will be used to develop intro section of your research proposal.

(See page 260 of Cozby). Each group member should use different

articles.

Begin by listing your article in APA reference style

Each summary should includeEach summary should include Summarize main message, key

information or finding, or recommendation from the article

(a few sentences to 2 paragraphs) . Describe how this info justifies the

importance of your project

(a few sentences to 2 paragraphs) and/or Describe how this article helps you

develop research hypotheses, measures, or procedures for your group project.

Reflect about the article...Reflect about the article...

What was important for you about the article?

How does it relate to your project?

How might it help you improve your research?

What might you do differently if you were going to repeat that research?

Part II: Part II: Practice evaluating literaturePractice evaluating literature

For both articles, write (or summarize if long) 1) the study’s research questions, 2) hypotheses, 3) the problems that their research study

addresses. 4) Describe how the authors justified the need

and importance of their study. Find the above in the introduction section of

the article. Attach your articles to the assignment.

Introduction section of articleIntroduction section of article

Purpose of study and research question(s) Problems related to study topic Literature review Rationale (justification) for the study Hypotheses

Type all assignments Double space Use SPELL CHECK

PROOFREAD.

USE CORRECT GRAMMAR AND PUNCTUATION.

Citation - APA StyleCitation - APA Style

Jones (1999) said blah, blah blah. Blah, blah, blah blah, blah, blah (Jones,

1999). Jones, Higa, and Vasquez (2000) said blah,

blah, blah. Blah, blah, blah blah, blah, blah (Jones,

Higa, & Vasquez, 2000). Blah, blah, blah (Smith as cited by Jones,

1999)

Conceptualization Conceptualization Operationalization Operationalization

Idea

Conceptualization

Operationalization

Clarificatio

n

What do I mean by ____?

How will I measure ___?

Measurable & Observable

OperationalizationOperationalization

Re-define a variable in terms of steps to measure

What the researcher must do to measure it

ExamplesExamples

Conceptual Definition Operational Definition

Amount of Sunshine The number of hours exposed to sun

Growth of Plant Daily growth of plants in height

Happiness Choice from “Very happy – Happy – Neutral – Unhappy – Very Unhappy”

Operationalizing:Operationalizing:Easy-going Easy-going (multi-dimensional)(multi-dimensional)

Looking for easy-going roommate

What could you do to screen if potential roommate would be “easy going?”

What would you specifically measure to determine “easy going?”

OperationalOperational definitiondefinition

A definition used to measure the concept Breakdown the concept into specific, objective,

measurable components Specific and clear

-- any two people

measuring the same phenomenon

would get the same result