Help regarding Medialab randomization and multiple questions

I have been using Medialab to design a study and I have a few questions. I've checked the forums for answers but have not been able to find one that was directly addressing my issue.

1) Is there a way to add multiple questions to one page in Medialab without using html. (I want to collect Demographic data and would like to ask a free response question, a scaled response, and a multiple response on one page, is this possible and how?). Is it possible to add multiple questions of the same type?

2) Is there a way to easily randomize conditions between subjects. I do not simply want to reorganize items in the questionnaire but I want to show different participants one of three different movies (assigned randomly between subjects) and skip the other 2 or do I have to have 3 different conditions each containing a different movie and then assign them to a condition manually.

3) Is there a way to add a row of empty cells in the experiment editor so that I can insert a new .que?

4) How can I add .mov movie files into Medialab?

Reginald,

1. Check the sharing area of the forums for a custom item that measures some standard demographics. It is HTML (!) but you can edit it in a text editor--the changes you will need to make should be minor but feel free to ask us to help if you run into trouble.

2. Do you want true random (probably resulting in unequal n's), or an equal number of each movie across conditions?

3. Just add the questions at the end. Number them to fall between the items where you wish them to appear--e.g., if between 3 and 4, then number then 3.1, 3.2, 3.3, etc. Press SORT and then RENUM. It's a method used from OLD days of program coding. Check out the section in the guide on question numbers.

4. Select the "Movie" item type and enter the file name of your movie in the file name field. Or do you mean how to play .mov files that don't seem to play when you do that?

1. The only problem I've found with the html is that when a subject enters the data, the spreadsheet doesn't seem to record the responses correctly (I get 0 or 99 for every response)

2. I need an equal amount of each movie across conditions

3. Thanks for the info on the sort and renum. I think I have the hang of it now.

4. Got the movie to work just converted to wmv. How can I get the movie to play directly in the center. I tried using parameters but how do I enter multiple parameters?

Did you try running the demographics sample? Did you find that you saw only missing data in that sample??

If you need equal n's you can't really do it randomly. It gets even more complicated if you are doing the experiment across multiple computers because each machine doesn't have a convenient way of knowing what conditions the others have run. The easiest solution for equal n's is to create a subject assignment list in Excel or some other program (or numbers in a hat) that generates random values. Then use these to create an autostart file that can automatically assign your subjects to conditions based on their subject ID.

For more detail, see:

[URL]http://www.empirisoft.com/medialab/help/preferences.htm#prefs_auto[/URL]

You might also look at using the[I] omit conditions[/I] (see guide) function as a way to bypass the videos you don't want seen in each condition.

As far as centering your movie goes, it should be centered automatically if you are using a "movie" item type. If it's not centering you can manually add parameters such as (t100,l100) e.g., to have the top left corner at 100 pixels from the top and 100 pixels from the left. If the movie is a backvideo to some other item, then the parameters can be added after the filename in the filename field, e.g., mymovie.wmv (t230,l160). take a look at the section on parameters in the users guide for more details.