variables and experimental design Flashcards
independent variable
some aspects of the experimental situation that is manipulated by the researcher - or changes naturally- so the effect on the DV can be measured
dependent variable
the variable that is measured by the researcher
operationalisation
clearly defining variables in terms of how they can be measured
independent group design
The participants only perform in one condition of the independent variable
the performance of the two groups will then then be compared
repeated measures design
The same participants experience all conditions of the experiment
Following this, the main scores from all conditions would be compared to see if there was a difference.
matched pairs design
participants are paired up together based on variables that has been found to have an affect on the dv
- then one participant from each pair would be allocated to a different condition of the experiment
-it takes into account participant/extrainous variables
Disadvantage of repeated measures design
-order effects are presented =participants my have practiced in the first condition,which cause them to before better in second condition or participants may experience boredom in the second condition=may not do the task as well
Strengths of repeated measures
-Eliminates participants variables,as the same participants take part in both conditions
-fewer participants are needed= not as time consuming finding and using the participants.
Strength of independent groups design
-There are no order effects as participants only appear in one one condition
-The demand characteristics are eliminated as participants are less likely to guess the aims of the study
C
how to get rid of demand characteristics
use a double blind procedure
(researcher +participants do not know which condition they are in
How to get rid of order effects
researchers can use counterbalancing
(half of the participants do condition A first then B, and the other half will do condition B first then A
