What is experimental design?
The process of deciding how to implement scientific research.
Process to implement scientific research
What is a true experiment?
What is an independent variable?
Variable whose effect has to be
measured in an experiment.
What is a dependent variable?
Whose changes depend on the
manipulation of the independent variable.
What is a confounding variable?
a type of extraneous variable that not only affects the dependent variable, but is also related to the independent
variable.
What are extraneous variables?
any variable that you’re not investigating that can potentially affect the dependent variable of your research study.
What is a quasi-experiment?
Experiments where participants are not randomly allocated by the experimenter into conditions (creating non-equivalent groups)
of the manipulated independent variable or where the researcher does not control the independent variable.
What are natural experiments?
the study of a naturally occurring situation as it unfolds in the
real world.
Types of experimental designs
What is the independent samples design?
two experimental group is generated. One group performs main ‘experiment’ while the other one is assigned ‘control’ experiment.
What is the placebo group?
This is similar to control grouping that they
experience exactly the same condition as experimental group except for the level of independent variable that is thought to
affect the dependent variable.
What are participant variable/ non-equivalent groups?
refers to condition when difference in results between experiment and control group can be attributed
to different ability of participants in two groups.
How do you overcome participant variability?
What is repeated measures design?
What is matched pairs design?
a type of experimental design where each participant is matched with another participant who is similar to them on certain key characteristics. Once participants are matched into pairs based on these characteristics, one member of each pair is randomly assigned to one experimental condition, while the other member is assigned to another condition. This ensures that any differences observed between the conditions can be attributed to the manipulation of the independent variable rather than to differences between participants.
What are the advantages of matched pairs design?
What is a lurking variable?
a variable that is not accounted for in an experiment that could potentially affect the outcomes of the experiment.
What are order effects?
refers to differences in outcomes due to the order in which experimental materials are presented to subjects.
What are the disadvantages of matched pairs design?
What is a single participant or small n design?
These types of designs are conducted in medical research where there are few participants suitable for the research.
Steps of hypothesis testing
What is a null hypothesis
represents a theory that has been put forward, either because it is believed to be true or because it is to be used as a basis for argument, but has not been proved.
What is the alternative hypothesis?
a statement of what a hypothesis
test is set up to establish.
1. Opposite of Null Hypothesis.
2. Only reached if H0 is rejected.