Preferences and Options

Fonts and Colors

You can change the fonts and colors MediaLab uses during experimental sessions. Select Edit Preferences > Font & Colors. You can set fonts and colors separately for windows that display text provided by you and for windows that allow subject input.

On-the-fly Editing of Word Documents

If this option is checked, then you can edit Word or WordPerfect documents as you run through the experiment simply by double clicking on them. You may want to disable this when you are running actual subjects.

Hide MediaLab Rats

For the politically correct and the phobic--you can choose to have MediaLab hide the rats from the main window with this option. For the phobic, note the opportunity here to start your systematic desensitization!

Disable System Key Sequences

Selecting this option will disable any key sequences that would allow participants to explore your computer or otherwise interfere with your experimental session. The key sequences such as ALT+TAB, CTRL+ALT+DELETE, and CTRL-ESC will be re-enabled after the session is over. Caution should be used here such that you have fully tested your experiment before setting this option. If for any reason, the program locks up while these system keys are disabled, you would have to turn the computer off and restart it (e.g., since CTRL-ALT-DELETE would not be an option for closing the program). Note that this function may not work on Windows XP.

Double-Click to close MediaLab

A small convenience that allows you to double click on the blue area of the MediaLab window in order to close the program.

Use Alternate Data File

Click the button to its right to browse for a folder on your computer or network. MediaLab will write the data to this folder instead of the experiment folder (default). This is especially useful if you want to run your experiment from a CD-ROM.

Also, because you can specify any location for the data using the "alternate data folder," you can choose to gather all of your data on a central computer on your network. To specify another computer as the location for your data files you need to "map the drive" on the other computer as a drive letter on your computer running MediaLab (e.g., as h:\ or s:\ --you may want to ask your network administrator to help you with this if you are unfamiliar with mapping drives on other computers). You can then specify the alternate data folder by using this mapped drive, e.g., "h:\medialabdata."

When MediaLab sees this, it will create a folder within the alternate data folder with the same name as the experiment file, e.g., "h:\medialabdata\experiment1" and will write the data as it normally would to this folder.  Please be aware that specifying a data folder that is not located on an actual machine in the network (i.e., Dropbox, cloud storage) would require an active internet connection anytime that data is being gathered. Otherwise, this could result in an error when trying to run your experiment because MediaLab will not be able to locate the folder to which it is attempting to write the data.

If you have multiple computers write data to this same alternate folder, it is recommended that you use a "Unique Machine Code" (see below) for each computer. This 3-letter identifier of each computer will be appended to all of its data files. This serves to identify which data files came from which computer and also helps to prevent conflicts that may occur from multiple computers attempting to write to the same files at the same time (since each computer will write to its own unique files). These multiple files can be easily merged later using the FileMerge utility provided in MediaLab's data menu.

Unique Machine Code

Type any extension here that you want appended to data files produced on the current computer. This helps to identify the machine on which data was collected. Leave this field blank if you don't want a code appended to the data file names (default).

Password to End Option

You can set a default password that will be required at the end of every experiment. This saves you the trouble of creating a separate password item in your experiment. If you forget the password, the secret key sequence CTRL+RIGHT ARROW will skip you out of it. No password will be required if this field is left blank.

Where to Find Supporting Applications

For most users, these fields can be left blank because MediaLab will automatically know where these applications are. However, if you get an message saying that MediaLab can not find one of these applications then you can fill in these values and MediaLab will search there. You can click the "…" button to the right of each field to browse your computer.

Saving the File

Click Save to save your work or click Close to cancel the changes. Click SaveAs to save the current configuration to a new Preferences file. When clicking SaveAs, you can also then select "Save as Type" and save the colours and fonts to a new Quick Style file if you like (see below).

Load Other Preferences File

Allows you to load the preferences saved in another file. The default.mlp preferences file is always loaded when MediaLab starts. You can edit and save the default preferences under a new name and then load your new preferences file before you begin running your experiment. This can be useful if different members of your lab have different preferences for how MediaLab operates. Remember that if you're only changing colors and fonts, then it's much easier to just create a new QuickStyle file (see below).

Mute MediaLab Sounds

Upon certain events MediaLab will give audible feedback by way of beeps and clicks. To turn off these sounds check this option.

Disable Clear Data

Prevents the Clear Data button from being pressed at the start of a session. This is a handy option if sessions are being started by users who are unfamiliar with the program.

QuickStyles: Create and Apply Multiple Style Files

MediaLab automatically loads the default preferences file. If you want load a different preferences file, you can select "Load Other Preferences File" from the Preferences menu. You can create, edit and save as many Preference files as you like.

Quickstyle (.mlq) files are just like Preference files (.mlp) except that they contain ONLY font and color information. You can create many quickstyle files with various foreground and background color combinations as well as font options. The benefit of quickstyle files is that you can instruct MediaLab to apply a different quickstyle file at any time during the experiment or in the middle of a questionnaire. In the parameter field of any experiment or questionnaire item you can name a quick style file preceded by a $ which will cause MediaLab to switch to that style. You are no longer limited to using a single set of color and font options.

How QuickStyles work

To create a quickstyle (.mlq) file, select QuickStyles from the Preferences menu. You can then select a configuration of fonts and colors. Select SaveAs and save the quickstyle file with a name of your choosing (e.g., mystyle1.mlq). You can either save it in the MediaLab Styles folder so that all experiments can use it, or you can save it to your experiment folder to make it available only to your current experiment.

Then, in your questionnaire or experiment files, enter the name of the style file preceded by a $ in the Parameter(s) field of any item, e.g., ($mystyle1). When MediaLab sees this it will read the style file and apply it immediately. MediaLab will first look in your experiment folder for the file (e.g., mystyle1.mlq). If it doesn't find it, it will look in the MediaLab Styles folder. If it finds it, it will immediately apply that style to your running experiment. You can have as many quickstyle files as you like and can apply them however frequently you like. The currently applied style will remain in effect until you request a different style file, or until ($off) is encountered in the parameter field of another item.

Aside from added flexibility of formatting, this allows you to store color and font information within your experiment folder so that it's always available. If for example, you send someone your experiment folder, the formatting will remain the same so long as the quick style files are included in the folder. This also means you no longer have to worry about loading the correct Preferences file before each experiment because your experiment takes care of this for you.

Note that you don't have to use quick style files at all. If you do not apply any quickstyle files in your experiment, MediaLab will simply use the colors and fonts specified in the Preferences file (e.g., default.mlp which is loaded automatically).

Foreign fonts

If you need to display foreign characters in MediaLab there are a few options that you can try.  In MediaLab, select Preferences and then Edit Preferences to choose the a compatible font for use when running your experiment (MediaLab supports most double-byte fonts such as Arial). Also under Preferences, you can select the Character Set option to select a script that works best with your language and font. Finally, also under Character Set is an option to right-align the text for question wording and open-ended responses. Finally, in the Experiment Editor, under Options, you can select an Editor Font and chose a font that works with the characters you need while editing your experiment. This step should be taken after setting the font and script preferences in the main MediaLab window.

Note that if you are designing experiments in a language other than English, you can also modify the messages that MediaLab displays so that they are in your preferred language (see below). We can also help you with a custom Continue and Go Back button for your language—let us know if you need this. In fact, there is already a series of Continue and Go Back graphics in various languages located in the C:\MediaLab\Graphics folder. If you would like to use them, simply replace C:\MediaLab\Graphics\continue.bmp and C:\MediaLab\Graphics\goback.bmp with the ones located in the language subfolder of your choice (e.g., Chinese, German, Greek, Japanese, Spanish).

Modify message text

MediaLab presents various messages during an experiment. You can edit the content of these messages to suit your specific needs or even translate them into an alternate language. You will find two files in the "styles" folder called "messages.txt" and "substitute.txt" which you can edit in any text editor. Messages.txt contains all of the possible feedback that MediaLab presents to subjects during an experiment:

How to modify MediaLab messages

Do NOT modify messages.txt! That would be bad. Instead, create and modify a file called substitute.txt

If you would like to customize or translate messages simply copy the messages you want to change into substitute.txt. Make sure you copy the entire line including the ID number. Change only the text within the quotation marks. MediaLab will substitute messages based on their ID number. The substitute file you make may contain all of the messages in this file or just a subset that you want to change. You can put the substitute.txt file in the C:\MediaLab\Styles folder or in an experiment folder of your choice.

For example, you could copy messages 103, 104, and 106 from "messages.txt":


And copy them to "substitute.txt" where you can change them to anything you like:


If you were to do that, then these messages (103,104,106) would be used instead of those contained in the message.txt file.

Here's how it works:

Every time MediaLab starts an experiment, it accesses the messages it will use from the main messages.txt. It will then look in the Styles folder for a file called substitute.txt. If it finds it, it will read your custom/translated messages and substitute them in the experiment. Note that if you place the substitute.txt file in the Styles folder, then all experiments will use the substitute messages. If you want to substitute messages in a particular experiment, then simply place the substitute.txt file in your experiment folder. Finally, you can place one substitute.txt file in the Styles folder (which will affect all experiments) and another in your experiment folder (which will affect only that experiment). If the same message IDs are contained in both locations, priority is given to those in the experiment folder.

Using an AutoStart File to Automate Subject and Condition IDs

By default, each time you run a MediaLab experiment, you need to enter a subject ID and condition. You can automate this process by using an AutoStart file. All you have to do is generate a text list of subject IDs and conditions and call it "autostart.txt" and place it in your experiment folder.  For example:


When you run the experiment, MediaLab checks to see if an autostart.txt file exists in the same folder. If it does exist then it automatically runs the next subject ID and condition on the list. If it doesn't then you will be prompted for the subject ID and condition as usual.

MediaLab will mark the subject ID condition with a * so it knows where to start next time. Following the session, MediaLab will ask if you want to run the next session--if you say yes it automatically gets the next subject ID and condition from the list and runs it. This way you can run sessions all day on multiple computers and never have to enter a subject ID or condition. Note that you will probably want to create a unique list of subject ID's and conditions for each computer to prevent redundancy!

Finally, an alternative way of using the AutoStart feature is to type "select subject" as the first line in the autostart.txt file. If you do this, then MediaLab will prompt you only for the subject ID. It will then look up the condition for that subject ID from the list and run it automatically. This is useful if you want to have a constant autostart.txt file on all of your computers and don't mind keeping track of which subjects still need to be run. It simply eliminates the need to keep track of which conditions to assign.


Advanced Hints for AutoStart

Using a substitute.txt file, you can have a blank message ("") defined for the end of session event. If MediaLab sees that you have no message and you are using an autostart file, then it will proceed automatically with the next session without asking if you want the next session run; it will simply start. Doing so requires ctrl-alt-delete when you finally want to escape.

Note about ending sessions early:

The autostart.txt file will only be updated if a session is completed. You can end a session in two ways.  One is to press ctrl-alt-delete and choosing to shutdown the MedialLb program--this will shutdown the session, no data will be saved, and the autostart file will remain unchanged. The other is to press ctrl-alt-right, which is the key combination to end a session. If you end a session in this manner the data will be written including missing values for questions that were never answered and you will be asked if you would like the autostart file to be reset as it was before the session. Answering yes to this will prevent MediaLab from scratching this session off its to-do list.