Week 2: Research designs

• A between groups/independent measures design is when participants can only belong to one experimental group e.g age, gender
• Within subjects/repeated measures design is where the same participant takes part in all conditions e.g testing before and after an intervention
• The tests used for a between-groups design are:

  • Independent t-test
  • Mann Whitney U test
• The tests used for a within-groups design are:

  • Repeated measures t-test
  • Wilcoxon Signed Rank test
• A Quasi-experimental design is a study where participants are grouped according to an attribute that they possess e.g. gender.
• A mixed factorial design is a study with at least two independent variables, where participants experience one level of at least one variable and all levels of at least one variable.
• A cross sectional design is a study exploring a relationship where all of the data are collected at a single point in time.
• A simple design is a study with a single independent variable
• A dependent variable is measured by the experimenter and compared across different conditions or cells of the experiment
• A cross-lagged longitudinal design is a study exploring a relationship where all of the variables are measured at the same time across different time points.
• A cell is a conditions where participants experience a specific combination of two or more independent variables.
• A longitudinal-correlational design is a study exploring a relationship where some variables are measured at one time point, and other variables are measured at another time point.
• An independent variable is manipulated by the experimenter in order to create a set of experimental conditions that vary systematically
• Levels of an IV are the different experimental conditions that are created by manipulating an independent variable