A students changing level of interest and background knowledge in algebra, during a study on the effects of response card quiz r
eviews on the next-day quiz performance is a potential _____________________ to the investigation and should be monitored 1. application variable
2. systems variable
3.confounding variable
4. reliability variable
Explanation:Confounding variable is the variable that indicates about the external influential factors that produces the manipulated consequences of independent and dependent variable.This variable can lead to producing useless outcomes in an experiment.
According to the question, the changes occurring in interest of student in algebra can be due to the outside factors which are not generating the actual results and thus, experiment is getting ruined.
Other options are incorrect because application variable remain same for the experiment,system variable are the variables of certain system and reliability variables describe about the variable on which dependent or stable.Thus, the correct option is option(3)
