Type of experimental Design Flashcards
type of experiments design (independent measures, repeated measures, matched pairs) (10 cards)
What is independant measures design?
involves using different people in each condition and only they complete that condition.
Strenghts of indepdent measures design?
Reduces demand characterestics. Since each participant only takes part in one condition, they don’t get bored, tired, or improve through practice, which makes the results more accurate and valid. Additionally, different participants are used in each condition, so it’s harder for them to guess the aim of the experiment.
Quicker for a psycholgosit to complete (both conditions can be done at same time in same day). means experimenter can do larger data sets in each. adds to valididty as results more accurate as larger data grps, and conditions done at same itme.
Weaknesses of indepdentant grp designs?
A weakness of independent measures is that individual differences are more likely to affect the results. Diff IQ levels, personalities in each groups (lowers vlaidity as other factors that could affect DV)
Another weakeness means eveb more paritcipants needed. means more money and more expensive so it is less practical.
What is repeated measures design?
Using the same people in each condition.
Strenght of repeated measures?
: A strength is that individual differences are less likely to affect the results. Same ppl being used. adds to validity as more controlled and no other infleucnes.
Another strength is that psychologists do not need many participants. less expensive. adds to practicality
Weaknesses of repeated measures?
A weakness of repeated measures is that there is an increased likelihood of demand characteristics. ppl more likely to guess aim of the pariticpant and change their behaviour. this questions validity as they can identify aim of experiment.
weaness means that order effects can impact. participants doing it twice, means they could have improved from last times or could be more tired. questions validity as the results can be impacted by smth else which means more innacurate.
How do we use countebralancing to overcome order effects?
participants are divided into two groups and do conditions in different order… which ensures that each condition is tested first for some ppl and last for some ppl, so order effects balanced out.
What is matched pairs design?
Like independant measurers where diff pariticpants do each condition.
However, pariticpants are matched/paired with another based on similar characteristics.
For example, ppl tested on iq. and two ppl who have similar iq, one placed in condition a, one in conditopn b.
weaknesses of matched pairs design
very time consuming as need to conduct extra tests to match them. can question validity as less time efficient- reesearcher may even take short cuts- increaisng error.
impossible to match two people exactly… questions vlaidity as individual differences can still have some affect.
strenght of matched pairs design.
individual differences less lijkely to effect (mathed on similarities). adds to validity as less other infleuces and extraneous variables.
lower order effects and demand charactercis. only take part in one condition so wont suffer from order effects. less likely to also guess study aim. adds to validity as results not affected by any unnatural behaviours.,
