Experimental Designs

I N D E P E N D E N T

one group of participants do condition A and a second do condition B (so diferent independet variables) then the DV of each group is compared

strengths

→order effects aren’t a problem

→demand characteristics are reduced

limitations

→participant variables may cause a confounding variable

→requires a greater amount of participants

how to deal with these issues

→randomly allocate participants by drawing names from a hat

R E P E A T E D M E A S U R E S

the same participants take part in all conditions of the experiment

strengths

→fewer participants are needed, so time is saved and money

→participant variables are controlled

limitations

→order effects: the order in which participants complete their tasks may affect their performance

→demand characteristics

how to deal with these issues

→counterbalancing the tasks (half of participants do AB, and half do BA)

M A T C H E D P A I R S

participants are paired together based on a shared variable or a factor which allows the researcher to place them in coordination to their study

• there’s a pre-experiment which indicates how participants will be grouped then come the experimental designs.

strengths

→helps control participant variables

limitations

→time consuming

→difficult to match accurately

→only matches on the known variables

how to deal with these issues

→pilot study for the key variable to match on (basically evaluating the matched pair variable before going forward with it)