control and realism

control and realism seesaw

standardisation

• means all p’s experience identical procedures + materials

• all p’s have same experience of being in the study

• controls for extraneous variables- can be sure measuring effects of IV on DV

extraneous variables

• any variable other than IV which might affect the DV

• participant variables= characteristics of individual p’s eg age, gender

• situational variables= features of the situation of environment eg time of day, weather

standardised instructions

• all p’s given same instructions delivered in the same way

• instructions are scripted and either read aloud by same researcher or are read by p’s

• control for investigating effects and researcher bias

investigator effects

• anything an investigator does (consciously or unconsciously) which has an effect on p’s behaviour within a study

• direct=interacting with p

• indirect= as a consequence of how study is designed

researcher bias

• a type of investigator effect which results in a skew or bias

• eg putting all your friends in 1 group

randomisation

• refers to the use of chance wherever possible in the deign of a study

• eg random generation of word for a word list

• randomise the order of words in a words list

random allocation

• use of chance to allocate p’s to each pf the conditions

• use either lottery method/ random number generator

positives of random allocation

• controls for researcher bias/ investigator effects

• AND for participant variables

• ( does not eliminate p variables- just minimises them

control groups

• 2 (or more) levels/ conditions of the IV

• experimental group- change in IV

• control group- no change in IV (placebo)— everything the same so have standardised experience except for manipulation (change of IV)

• provides baseline for comparison/ analysis- essential in order to draw causal conclusions

demand characteristics

• any cue or clue from the researcher or from research situation that may be interpreted by p’s as revealing the purpose of an investigation

• this may lead to a P changing their behaviour within the research situation

single blind trial

• only p’s are blind to aim

• controls demand characteristics

double blind trial

• researcher and p’s do not know aim

• controls demand characteristics AND investigator effects

pilot studies

• a small scale trial run of a study to test analysis of the design

• with a view to making improvements, before proper study conducted