Transcript Internet Research: Issues, Problems and an Example Technique

Web-Based Research:
Issues, Problems and an
Example Technique
John H. Krantz
Hanover College
Outline
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Brief History
Issues in Internet Research
An Example Method
Problems and Solutions
History
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Email for 2-3 Decades
1995
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Krantz, Ballard, & Scher (1997) Within Subjects
Reips (1997) Between Subjects
First True Web Experiments
July 1995 List of Online Psychological
Research – sponsored by APS for awhile
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http://psych.hanover.edu/research/exponnet.html
Almost 200 studies and study sites listed
Why Do Internet Research
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Musch & Reips (2000)
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Sample Size
Statistical Power
High Speed
Ability to reach participants in other countries
High external or ecological validity
Low cost
Ability to replicate a lab experiment with more
power
Special populations
Issues
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Is the Sample Representative
Yes and No
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Important to remember base of comparison
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Ideal vs. Lab
Krantz & Dalal (2000)
Much more diverse that most lab samples
Especially in age and education range
Race is generally limited as is nationality
Sample Characteristics:
Gender
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Are Internet Samples Male Dominated?
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Krantz & Dalal (2000)
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GVU 1st (1994)
Reips (1996) English:
German:
Krantz, et al. (1997)
Pasveer & Ellard (1998) 3rd Study
% Female
5%
43%
18%
44%
71%
More Recent
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Caddell & Utt (2004)
Meyerson & Tryon (2003)
77%
45%
Sample Characteristics: Age
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Are we still testing college sophomores?
Krantz, et al. (1997)
43% > 30
Smith & Leigh (1997)
35% > 30
Pasveer & Ellard (1998)
45% > 25
GVU 1st
36% > 30
Caddell & Utt (2004)
60% > 30
Pattison & Rouse(2003)
16% > 30
Is the College Sophomore be
Making a Comeback
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Plot of activity of Psychological Research on the Net
50000
# Hits
40000
30000
2003
20000
10000
Monlth
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Pattison & Rouse (2004) 76% 18-22
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Sample Characteristics: Race
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How diverse are the samples?
Unfortunately in general samples, diversity is still
limited
Krantz et al. (1997)
89% White
Smith & Leigh (1997)
86% White
GVU 10th (1998b)
87% White
O’Neil, Penrod, & Bornstein (2003) 82% White
Meyerson & Tryon (2003)
93% White
However, as will be discussed later, web can make
it possible to access special populations
Sample Characteristics:
Nationality
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Where to do the subjects come from?
Largely North American, even US, even in
some European studies
Krantz, et al. (1997)
86% N. Am.
Senior, et al (1999)
>80% N. Am
This study was conducted in England.
Is the Data Any Good
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Emphatically Yes
Data Quality: Direct
Comparisons
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A number of studies, still, run both laboratory
and internet samples.
Krantz, et al. (1997)
Regression of web means on laboratory
samples (even though different types of
samples):
lab mean = 1*(Web mean) + 0
r2 = .99
Compare to Established Data
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Compare web results to previously published
data sets
Myerson & Tryon (2003)
Studied Sexual Boredom Scale of Watt &
Ewing (1996)
Matched sample characteristics
Found same internal consistency
Form of administration was not a significant
factor
Direct Validity Comparison
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Use same techniques to validate results
Pasveer & Ellard (1998)
Developed new scale
Internal consistency
Psychomectric properties
Data Validity: Arguments
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Reips (2000)
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Statistical Power
Limited Sample Population
Limited External Validity
Less than Optimal Voluntariness
Motivational Confounding
Experimenter Bias
Nontransparency
Limitations of what is feasible to research
Interesting Deviations
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Stern & Faber (1997)
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Milgram’s lost letter technique
Milgram, sent on
Stern & Faber, returned to sender
From doing favor to doing easy task
Often effects are smaller
Getting Subjects: General
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http://psych.hanover.edu/research/exponnet.
html
Other Pages:
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Social Psychology:
http://www.socialpsychology.org/expts.htm
The Web Experiment List: http://genpsylabwexlist.unizh.ch/
Getting Subjects: Special
Populations
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Advertising
Email Groups
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Careful, get permission
Can be thought spam
Netiquette
Discussion Groups
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Same, permission
Sample Method for Doing
Survey
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Birnbaum, M. H. (2001). Introduction to
Behavioral Research on the Internet. Upper
Saddle River, NJ: Prentice Hall.
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Lots of resources at http://ati.fullerton.edu/
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NSF sponsored classes at Fullerton on Social
Psychology
One more next January, look for the
announcement at this site
First Step: Where to put it
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Setting up a server can be easy
Apache web server
http://www.apache.org
Most popular server
Freeware
Any computer connected to web is now a
server
May have issues of firewalls & dynamic IP
addresses
Second Step: SurveyWiz
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In Birnbaum (2001)
Also linked to from http://ati.fullerton.edu/
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Under Birnbaum’s page
Freely available
We will build a very short survey to illustrate
Forms
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SurveyWiz uses web forms to collect data
What are forms:
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Elements to allow web page viewers to input
This data is then sent back to the server to be
processed
SurveyWiz
What the page looks like My Take
Can edit it with any web page editor
Examples I have done this
year
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Caddell & Utt
Pattison & Reese
Third Step: Collecting the data
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First way, let Birnbaum do it for you
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SurveyWiz is set up this way
<FORM action=http://psych.fullerton.edu/cgiwin/polyform.exe/generic method=post>
FTP://guest:[email protected]
You can type in the address box of your browser.
Note that this is FTP site. At the present time,
password is guest99, as shown above, and
permits download only.
Keeping the Data Local
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Second, get this perl script (found at
http://psych.fullerton.edu/mbirnbaum/program
s/PERL_script2.htm)
The script and instructions are at this site
Written by Billy Schmidt
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Also change code in form command
At my school the line reads:
<FORM action=http://psych.hanover.edu/cgibin/survey_wiz.pl method=post>
What is CGI
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Common Gateway Interface
Method for other programs to interact with
web servers
In this case, this perl program takes data
from web forms and stores them in a file
Stores data in Excel or SPSS readable files
Fourth Step: Example Data File
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Data File
Data coding scheme: all variable names
begin two numbers, see example
The perl program sorts the variables by
numerical order
Another Method of Survey
Generation
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Schmit’s Survey Assistant
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He manages data
More flexibility
http://or.psychology.dal.ca/~wcs/hidden/home.htm
l
What Do I Need?
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At NSF ATI site
List of software resources
What Problems are important
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Musch & Reips (2000) – 5 point scale
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No control over participant’s behavior
No control over motivation
Inability of participants to ask questions
Nonrepresentative sample
Manipulation and fraud
Ethical problems
3.6
3.4
3.3
2.9
2.4
1.5
Problems
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Eliminating Multiple Entries
Dropout
Security
Data Integrity
Multiple Entries
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People submit too fast, while waiting for
feedback
People will fake being two people
Usually have same IP address
SurveyWiz and most other methods, sends
the IP address of machine where survey is
being taken
Can eliminate more than one from same IP,
e.g. Schmidt (1997)
Security & Data Integrity
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If on public server, others can access data
and download
Others might fake pages to send data
(unlikely)
Keep data in non-public directories so only
researchers have access
Have CGI check for origin of survey to make
sure it is yours (Schmidt, 1997)
Dropout
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People will come but not finish
Or data is incomplete
Survey will sends a complete signal to help
you track
Can use: (O’Neil, Penrod, & Bornstein, 2003)
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Short sweet
Financial incentives.
If multiple pages to survey, several pages warmup so not drop-out during
Ethical Issues
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Should not think of Ethical Issues of Web
Research Alone
Compare to Ethics of doing Traditional
Research
Not let our comfort with what we have done
blind us to those problems
Conclusion
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Many Benefits
Easy Methods
Easy Resources
Not alternative to traditional methods
A new tool still needs to be used thoughtfully