Transcript Research Design Part II

Research Methods for the
Social Sciences:
Research Design Part II
Tuesday, February 02, 2010
Data Collection & Procedures
Division on Addictions, Cambridge Health Alliance
Harvard Medical School
Class Objectives

Review:
– Sampling
– Qualitative vs. Quantitative
– Data collection procedures
– Your research ideas
Sampling
Selecting a group of
people from a larger
population.
 Why?

– Size
– Time
– $$$

Sampling error
– Sampling bias
Types of samples

Nonprobability
– Convenience
– Quota
– Purposive or judgmental
– Snowball
Types of samples

Probability
– Simple random
 Select at random using random number generator
 Same chance
– Systematic
 1,000/100 = 10th
Types of samples
– Stratified
 Divide population into strata
 Sample = population on a specific characteristic
– E.g., AGE
1000
800
66-85
600
46-65
26-45
400
200
0
Sample
Population

Cluster
Examples of sampling

Special populations
– College students -> Other populations
– Treatment Seekers -> Everyone with a
specific problem
Who’s collecting the data?

Secondary
– Data collected by others
 E.g., Researchers,
government
– Strengths:
 Save time & money
– Weaknesses:
 No control over study design
or data collection
Who’s collecting the data?

Primary
– Data you collect on your
own
– Collaborations
– Strengths
 You control study design,
sampling, data collection
– Weakness
 Time &”Money
Sample size

Power analysis
1. Sample size n = ???
2. Ability to measure effects
What kind of data are you
collection
Qualitative
Interactive
Interview
Naturalistic
Observation
Written
Case
Description Study
Quantitative
Experimental Correlation Survey
What type of data are you
collecting?
Qualitative
 Systematic but nonuniform
 Field work or participant observation

– Natural observation
– Case study
– Interactive interviews
– Written descriptions by participants
Open-ended
 Record everything

Natural Observation
Narrative record
 Video/audio recordings
 Sampling

– Time
– Event
– Situation

After you will categorize and code data for
analysis
Case Study
Review: Biographical data;
Medical records; Family
history; Observations;
Interviews; Psychological
tests
 Look for variables that might
help explain behavior your
are studying.

Interactive Interview/focus
group

Similar to natural observation
– Interact
Ask specific questions and lead discussion
 Data collection methods similar to natural
observation

Written description
Journal
 Long narrative
 Open-ended survey responses

Coding
Simple coding: Counting the number of
behaviors in a recording
 More complex coding: Categorization

Qualitative

Content Analysis of open ended responses
– Missouri Self-excluders
– Question: Why did you self-exclude?
– “Because my wife made me.”
– “I was sick of worrying about finances.”

New computer programs can categorize
for you.
What kind of data are you
collection
Qualitative
Interactive
Interview
Naturalistic
Observation
Written
Case
Description Study
Quantitative
Experimental Correlation Survey
What type of data are you
collecting?

Quantitative
– You are attempting to measure how large an
effect is.
 Experimental
 Correlations
 Survey
– Two types of data collection
 Self-report of behavior
 Actual behavior
Modes of Data Collection:
Self-report
Questionnaires/
Surveys

–
Pen and paper


–
–
in person
mailed
Internet-based
survey
Random digit dialing
Modes of Data Collection:
Self-report
Interviews

–
–
–
–
Computer Assisted
Personal
Interviewing (CAPI)
Telephone
interviews
Face to face or
personal interviews
Focus groups
Computer Assisted Telephone
Interview
Surveying Behavior

Strengths
– Specific and quantifiable
– Replicable
– Larger sample size compared to qual.
– Generalizable

Limitations
– Self-report
 Allows biases
Modes of Data Collection:
Observing Behavior

Implicit Association Test
– Computer program
 Categorize objects
 Faster = stronger association

Computers and Internet
– Allow us to observe actual Internet gambling
behavior
– Could also be used for online shopping
behavior
– What else?
Example of IAT
When will you collect your data

Longitudinal
– Multiple data points

Cross-sectional
– One data point
When is it too much?

Only collect data you will
use
Time = Compensation
 Time = Work
 Every 10 minutes = 7% drop
in RR (McCarty et al. 2006)

Response Rates
As the response rate
 Greater likelihood results will represent
the total population (i.e., generalizability)
 The higher the response rate, the more
accurate the survey.

Response Rates
Striving to achieve the highest rate you
can
 Low rates, might affect your ability to
generalize to the population as a whole
 At least 70%

Recap
Each methodology and data collection
method has strengths and weaknesses
 Consider using a combination

– Focus group to test survey questions
– Journal to help recall and periodic surveys
– Close ended and open ended questions
Recap cont

Research design, Sampling, and Data
collection
– trade off b/w your hypotheses, variables, and
reality.
– Balance: time; money; and effort
Primary Sources
Thames Valley University Disseration
Guide:
http://brent.tvu.ac.uk/dissguide/hm1u3/h
m1u3fra.htm
 Research Methods in Social Relations
