Title: Internet Research Methods in Psychology
1Internet Research Methods in Psychology
- R. Chris Fraley
- University of Illinois at Urbana-Champaign
- Seminar - PSYC 593 CF
2Introduction
- During the last decade an increasing number of
psychologists have begun to use the Internet to
collect empirical data. - The Internet has the potential to be useful for
two reasons - Integrated data management
- Whether you collect data from undergraduate
subject pools, community samples, or elsewhere,
you can use the same platform for research
design, collecting data, providing feedback, and
managing data. - Open laboratory
- Participants can take part in your research any
time of the day. - If desired, you can open your lab doors to people
from across the world.
3Our plan
- My objective in this course is to show you how to
design research studies that can be implemented
on the Internet. - Outline
- 1. What kinds of research can be done using the
Internet? - 2. How to obtain access to a web server.
- 3. How to create a basic HTML web page that can
be used to collect data. - 4. How to create Perl/CGI scripts to process and
save those data. - 5. How to do advanced things, such as randomize
stimuli/questions, randomly assign people to
conditions, and present items/stimuli on separate
pages. - 6. A discussion on ethics, sampling concerns, and
informed consent.
4Part 1Basic concepts and what can be done
5How the Net Works
- Most web pages are written in a language called
HTML (hypertext markup language). - HTML files exist on a web server. When a person
types in the URL for a specific file in his or
her web browser, the person is essentially
retrieving that pre-existing file from the web
server.
6How the Net Works
web user types a URL into the browser
web server locates requested HTML file and sends
it to users computer
web user the browser renders the HTML file as a
web page
7Static vs. Dynamic Web Pages
- The obvious limitation of using HTML pages in
this manner is that the users web experience is
statiche or she will see the same page each time
he or she goes to that address. - It is possible, however, to program the server to
deliver dynamic contentcontent that varies from
one situation to the next or from one person to
the next. - This kind of interactivity is necessary in order
to produce the kinds of web pages that allow for
creative, complex research designs.
8Dynamic Web Programming and CGI
- This kind of interactivity can be accomplished by
writing programs, called CGI scripts, that run on
the web server. - CGI scripts are often written in Perl, PHP, or
other languages. (Ill expand on some technical
details later.) What is important to note right
now is that those languages are available for
free and, with a bit of practice, are relatively
easy to use.
9Dynamic Web Programming and CGI
web user types a URL into the browser
- web server
- locates requested CGI script.
- Performs the commands and creates a new HTML
file. - Sends HTML file to users computer
web user the browser renders the HTML file as a
web page
10What Can Be Done with CGI Scripts?
- By using CGI scripts, it is possible to
accomplish a number of feats that are impossible
using standard web pages. - save data
- randomize the order of questions
- random assignment to conditions
- track participants over time
- implement complex branching patterns
- customize text and images
- create customized feedback for users
- Lets discuss some of these points in more
detail.
11Automatically Save Responses to a Data File
- One of most time-consuming aspects of conducting
paper-and-pencil research is data entry. - It is easy to write CGI scripts that save the
data automatically. - save as a comma-delimited text file (that can be
easily imported into SPSS or MS Excel) - save directly into a database (such as MySQL)
12snapshot of a comma-delimited text file
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14Provide Participants with Customized Feedback
- One of the most valuable features of conducting
research over the Internet is that it allows you
to provide instant feedback to the research
subject. - plot the persons scores
- create bar charts or tables that summarize the
data (e.g., means, SDs, correlations) from the
broader sample automatically
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17Substitution
- One of the perks of using dynamic programming is
that it allows for substitution. - In other words, you can take information that has
been provided by the user (or computed by some
other part of the script) and substitute that
into the web page that is sent to the user.
18My wifes name has been substituted into the web
page, making the questions tailored to me.
19Randomization of Stimuli Order
- In most questionnaire-based research, it is not
unusual for researchers to present questions in
the same order for each research participant. - In fact, many researchers who have placed their
questionnaires on-line have followed this
practice.
20Randomization of Stimuli Order
- There are obvious limitations of using the same
presentation order for stimuli. - Most importantly, there may be systematic order
effects that impact responding. - By randomizing the order in which items/stimuli
are presented, it is possible to minimize these
kinds of problems. - It is possible to randomize the order of stimuli
quite easily using a CGI script.
21First time the page is loaded
22Next time the page is loaded the questions are in
a different order.
23Random Assignment to Conditions
- It is also possible to use these same
randomization techniques to randomly assign
participants to experimental conditions. - Importantly, it is easy to implement this in a
way that precludes research subjects from knowing
that they are in but one of many possible cells
of a research design. - Example
- http//www.web-research-design.net/cgi-bin/APS2005
/experiment1.pl
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26Measure Response Times
- It is also possible to write CGI scripts that
assess the amount of time that a user spends on a
web page.
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29Measure Response Times
- It is not advisable to assess response times for
decisions that can be made within a few seconds
(e.g., lexical decision tasks) because it can
take up to three seconds for a simple HTML page
to fully load. - However, by using multimedia applications, such
as Macromedias Flash, it is possible to assess
response times at a more microscopic level.
30Measure Response Times
- Example lexical decision application
- http//www.web-research-design.net/APS2005/lexical
decision.swf
31Use Complex Branching Patterns
- One limitation of paper-and-pencil questionnaires
is that it is difficult for participants to
follow complex branching operations. - There may be certain questions that should be
skipped if the participant is not married, for
example. - If you want to tailor the stimuli to a specific
user (e.g., a persons ideographically unwanted
traits), it is difficult to do so with a
paper-based test. - Again, CGI scripts can be used to implement these
conditional patterns.
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33Track Participants Over Time
- It is often desirable to follow a group of people
across time to study continuity and change in
attitudes, moods, behavior, and traits. - The Internet provides a useful way to track data
across time because people can - (a) log-on at their convenience
- (b) all submissions can be time-stamped
automatically by the web server - (c) the persons progress can be easily tracked
across multiple sessions
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36Learning How to Conduct Research over the Internet
- How do you do this stuff?!
37Learning How to Conduct Research over the Internet
- The first thing to note is that these techniques
are relatively easy to learneven if you have
very little experience in programming.
38Learning How to Conduct Research over the Internet
- What you need
- a computer with an Internet connection (dial-up
modem or high-speed) - a web server
- Professional hosting sites (e.g. , Netfirms)
- Create your own (e.g., spare PC, Apache software)
- software that is freely available over the
Internet - text editor (e.g., EditPlus (windows))
39Learning How to Conduct Research over the Internet
- What you need
- Patience
- Programming can be rewarding, but it can also be
frustrating. - Take breaks when you hit a problem
- Ask a blind eye to give it a look
- Check the details (semi-colons, commas, quotes)
- Use error checking short cuts
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