Conditional launches are a feature we put in before conditional sections were introduced allowing you to vary which external application is launched by a section based on the content of a variable name.
You can achieve the same effects using conditional sections (and the results will be far more intuitive). Indeed, our original reason for having this feature (providing varying stimuli based on experimental conditions) could be entirely replaced by conditional sections.
RiddleMeThis can launch an external application from a given section (i.e. the Launch Program property of a section, see Sections.) E.g. you might want to launch a stimulus in the form of a PowerPoint presentation, or some custom application. It's also quite likely that you want to vary the stimulus based on earlier inputs. RiddleMeThis provides for this by allowing you to insert a variable into the name of the program launched.
A simple example would be a study where you want to measure the subjects' responses to different stimuli based on what's entered in the "office use only" portion of the questionnaire.
Thus section 1 of the questionnaire might be password protected and include an independent variable named "WhichStimulus" and the two options are "StimulusA" and "StimulusB" (or you could set the value of the variable randomly, see Random Variables). Later you want to launch one of two external applications based on the contents of the variable "WhichStimulus".
To do this, you simply put "<WhichStimulus>" in the Launch Program field for the appropriate section. (This means that the contents of the question whose column id is "WhichStimulus" will be determine the program launched.)
Using a Variable in the Launch Program Field
The variable can be inserted into a larger string: "Launch_<WhichStimulus>" would become "Launch_StimulusA" or "Launch_StimulusB" in this case. Only one variable name can be inserted into the Launch Program field.