Task: Question Answering
Input (English): Question: Intrasubject experimental research designs: 
 Options:  <1> They use independent variables not manipulated directly by the researcher but through the selection of the participants. <2> They are based on the verification of independent groups assigned to the experimental conditions. <3> They combine two independent variables based on the characteristics of the participants. <4> They have lower internal validity than the intersubject designs when they do not use random assignment. <5> They use specific control techniques to control the effects associated with the order of application of the experimental conditions.
Output (English): 5