EXPERIMENTAL
RESEARCH
DESIGN
LECTURE 3
, RECAP EXPERIMENTAL DESIGNS (CH7)
• In Ch7 we discussed the experimental research strategy and its primary
goal – demonstrate cause-and-effect relationships between two variab
• To accomplish we said that it needs to do the following;
1) Manipulation of IV to create two sets of treatment conditions,
2) Measurement of DV to obtain sets of scores within treatment condit
3) Comparison of scores between the treatments.
4) Control of all other extraneous variables to prevent them from
becoming confounding variables
• By comparing scores between treatment the researcher can conclude t
differences observed have been caused by the treatment conditions.
,• There are TWO basic research designs that can be used by
researcher to obtain groups of scores that are compared in
experiment.
• These are:
1) Between-subjects design
2) Within-subjects design
, BETWEEN-SUBJECTS DESIGN
CH8
• The goal of the between-subject design experiment is to
determine whether there are differences between two or mor
treatment conditions.
• In this design the researcher manipulates the IV to create
different treatment conditions, and separate but equivalent
groups of individuals are assigned to each condition.
• This design whilst used in experimental research, it is also
used in the quasi-experimental and non-experimental
research.