WEXTOR is a tool for constructing and organizing a research procedure.  You begin by defining any between-subjects, within-subjects, and quasi-experimental variables.  You then define the order of these variables, see a visual representation of the experimental order, and modify the webpages needed to conduct the study.  Ultimately, you can conduct the experiment over the Internet or a lab-based computer.
        Let's put together a simple research study in WEXTOR.  Research on impression formation shows that the order in which we learn information about others influences our overall evaluation of that person.  We're going to put together a conceptual replication a classic study on impression formation.  Here's the example we're going to use.  Participants will be given 6 trait terms that describe an individual.  However, the order in which the traits are presented will differ for difference participants.  Even with the same list of traits, the evaluations of the targets should differ.
        Here are the lists of traits we'll use:
 

        We're going to put together this brief research study with 2 Factors (there's no within-subjects factor in this example).  The first factor is a between-subjects variable representing which list order a participant gets.  As a quasi-experimental variable, we want to know if the participant is a native English speaker.

        Respondents will read either List A or List B and then, based on only this limited information, rate the target on several personality traits (sociability, happiness, aggressiveness, and rudeness) as the dependent measures.

Getting Started:

1) go to the WEXTOR website at [ http://genpsylab-serv2.unizh.ch/wextor/en/index.php ].  If you haven't created a login id, go ahead and do that.  Once you've done that, get logged in.

2) Click Create/modify an experimental design to get started.  We want to Create an Experimental Design.  First, you need to name your experiment.  Let's call it "Impression Formation".  Click Create when you've entered the text.

Specifying the factors:

3)  Next, we begin to define each of our factors.   WEXTOR accommodates between-subjects, within-subjects, and quasi-experimental factors, and it provides brief explanations if you need a refresher.
        We need to specify how many of each type of factor our experimental procedure will have.  Open the drop-down menu below the between-subjects factor and select "1".  Use the drop-down menu for within-subjects factors to select ")".  Use the bottom drop-down menu to indicate that "Yes", we have a quasi-experimental variable.  If you try to move on without at least specifying you don't have any variables of a certain type,you will receive a friendly error message and let you correct your mistake.
        When you're done, click the > arrow to continue.

4)  Now we need to name each of the factors and specify the number of levels for each.  Using the Factor Information List provided above, enter the name and number of levels for each factor and then click the > arrow to continue.  For the Quasi-experimental factor, we do not require different webpages for each level of the factor.

5) Now we have to specify the name for each level of each factor.  Use the information in the Factor Information List above to enter these labels and click the > arrow to continue.

Specifying the Experimental Procedure:

6) Now, in STEP 4 of WEXTOR, we define the experimental conditions.  Two important things to note here:

        a) The name you specify here essentially creates a folder in which materials for a specific experimental condition (e.g., List A) will reside. Since, the name you provide will be part of the URL used in the experimental procedure,  you may want to use a name that will not reveal too much information to the research participant.  To this effect, WEXTOR offers a codename of sorts by default, but you can change this if you want.
                Let's rename the conditions using something more descriptive to us.  We'll name them using the first letter of each trait.  So, for Experimental condition 1, erase the default name that's provided and enter "ESCIII".  For condition 2, enter "IIICSE".

        b) Another important thing to note about this screen is it provides you the opportunity to eliminate any conditions you don't need, if you have an incomplete (i.e., not completely crossed) design.

7) In Step 5 of WEXTOR, we have to specify how many pages (i.e., webpages) the experimental conditions will consist of.  First, you should note that WEXTOR automatically generates 5 pages.  Take a minute to review those.
        OK, now let's specify how many pages we'll need (not including the automatically included ones).  The procedure will consist of 1 instructions screen, 1 screen consistenting of the trait list, and 1 screen of trait ratings.  So, that's 3 screens total.

8) In Step 6 of WEXTOR, we specify the names of the webpages we'll need.  Names are already provided for the automatically generated webpages.  Let's keep the names simple, so use these:
 

        WEXTOR can help protect the integrity of the filenames by adding some random characters to your filenames (so they aren't so obvious).  In this case, let's not worry about doing that.

9)  We don't need to worry about Step 7 because we don't have an within-subjects factors.  So, let's move on.

10)  Now we need to specify the question addressed by our quasi-experimental variable.  In the top textbox, type the question "Are you a native English speaker?"  In the next textbox, type the variable name "Nat_Eng".  We've called the 2 levels of the variable "Yes" and "No", but WEXTOR knows we may need to call them something different for the respondents.  In this case, those names work fine, so in the next textbox type "Male" and in the final textbox type "Female".  Finally, click the button for Radio buttons.  Then, click the > arrow to move on.

11) In Step 8 of WEXTOR, we need to specify that both groups in our quasi-experimental variable can be randomly assigned to either level of our between-subjects variable.  So, click all 4 of the check boxes and then continue.

Taking a Look at the Experimental Procedure:

12) Now, to help you see what you've done, WEXTOR can show you the layout of your experimental design.  Click the View option next to visual display of the experimental design.  You should see something like this:
 
 

This allows you to see the experimental procedure you've created and see if there are any changes you need to make.          We can use this display to walk through the experiment and see how it goes.       First, participants go to the index page; that's your homepage.  Next, they go to the start page which contains some general information about the experiment, as well as the informed consent.  After that, participants are assigned to one of the two experimental conditions (the ESCIII and IIICSE folders).        Regardless of the experimental condition, participants complete a few demographic questions, then read more instructions, then see the list of traits, then make their trait ratings, and then get thanked.  We'll want to include our debriefing on the Thank You page.        If you need to make any changes to the experimental procedure, you can use the < back button at the bottom of teh webpage to go back to the appropriate page, make the changes, and as you click the > continue button, WEXTOR will update the procedure.        You can click the 'download' button to save this visual display of the experimental design to your computer.

               When you're satisfied with the layout of the experimental procedure, it's time get specific about what's going to go on each page.  Here's what's going to happen:  Once we've made a few additions, we'll download a series of webpages that WEXTOR has made for us.  These will be the pages needed to conduct our study.

Adding Dependent Measures (HTML forms):

13)  Now, you're ready to start working with the content on the webpages used in the experimental procedure.  To this point, WEXTOR has created the webpages for the experiment and the special script needed to move between them.  Clicking on the name of a webpage in the list allows you to add content to it.
        This is how we'll add forms (special HTML tags for collecting responses) to our webpage.  You'll want to do formating work on your webpages after they've been downloaded.  This is where knowing some HTML or how to use a web editor comes in very handy.

        For the instructions page, we can add the content later.  Since everyone in each between-subjects condition will get the same trait lists, we can add that content with the HTML editor later, as well.  However, this IS a good place to add the rating scales for our dependent measures.
        Click the link for ratings.html.  You should see something like this:
 

This is where you add elements to the webpage for collecting responses.  WEXTOR gives you a variety of options and even provides an example so you can see what each looks like.        We want to have our respondents complete ratings for 4 traits; 2 that are positive and 2 that are negative.  These 4 traits are:  Sociable, Happy, Aggressive, Rude.         Let's use a simple 5-point rating scale, with radio buttons in a horizontal order.  Select the button for Radio Buttons in Horizontal order and click add.        Here's the text we need to enter:

             Item Name:  Sociable
             The question to enter:   How Sociable is this person?
             Left end label:  Not at all Sociable
             Right end label:  Very Sociable
             Number of radio buttons:  5

                After entering the information into the appropriate textboxes, click the > continue button.  After doing that, you can click the view button to see what it looks like.  If you don't like the way the text looks, that's ok because you can come along and change it later.  Right now, you just want to get the questions in there.
                OK, now we just need to use that same procedure to add 3 more ratings for a remaining 3 traits.  After entering those, if you click view again you can take a look.  You've now added the dependent variables!!  When you're done, click the > continue button.  This takes you back to the navigation screen.

14) Continuing on to the next screen, WEXTOR offers to collect the response latency for each page.  Response times can be useful information to have, so click the checkbox to get the response latencies.
        WEXTOR automatically assigns a user id to respondents.  We can leave the number of digits at 5.  Click the > continue button.

Downloading the Materials:

15) You're now ready to download the materials.  WEXTOR has created the webpages needed to conduct your experiment and the Javascript for moving between the pages.  Now, you need to download those pages and adjust the content to suit your needs.
        Click the download link and save the file to your harddrive.  As WEXTOR explains at this point, what you download is a compressed file, so you may need to use a program to decompress it (e.g., winzip).
        If you click the > continue button you get some information about the data you're collecting.  We'll come back to that in a minute.

16)  Find the compressed file you downloaded and open it up.  You should find a list of all the files needed to run your experiment.  For example, you should see the file 'ratings.html' where you made the trait ratings.

Finishing It Up:

17)  Essentially, WEXTOR has helped you make the skeleton for your research study.  Notice that there are 2 copies of some files.  Remember, each between-subjects condition is represented by its own folder, so you'll need different files for each folder (e.g., for the ESCIII folder, we need to have List A displayed, but the IIICSE folder needs to have List B displayed).
        Here's what you need to do:  Create a folder to house all your experimental materials, called "WEXTOR_IF".  Now, within that folder, create a folder called ESCIII and another called IIICSE.  Into these 2 subfolders, move one copy of each of these files:  demos.html, instructions.html, list.html, ratings.html, and thank.html.  Copy all other files you downloaded from WEXTOR into the WEXTOR_IF folder.

18)  All you need to do now is flesh it out by filling in the content.  For example, you need to add some instructions to the 'instructions.html' pages and the trait lists to the 'list.html' pages.
    Now, this is not an exercise in HTML, so I've completed the pages and made the completed project available for you to view:

        Completed WEXTOR_Impression_Formation_Example: 

                http://personal.centenary.edu/~rmweeks/ACS_tech/WEXTOR_materials/

• All I did was add some instructions, add the lists, alter the color scheme a little, and then upload the files to my server.  All in all, making the changes took me about 20 minutes with MS Frontpage.

Reips, U.-D. (2002). WEXTOR:  A Web-based tool for generating and visualizing experimental designs and procedure.  Behavior Research Methods, Instruments, and Computers, 34, 234-240.