Research methods Flashcards
define operationalisation of variables
- clearly defining variables and how they are intended to be measured.
define EV.
a variable that is not the IV, but may affect the DV, eg light, sound
Define confounding variable
- a EV that cannot be controlled, varies systematically with the IV.
Define and explain investigator effects
- any conscious/unconscious behaviours from the researcher that may effect answers from pps
what are the 3 types of experimental design?
- independent groups
- matched pairs
- repeated measures
Describe what an independent groups design is.
- each group only takes part in one conditions
- the mean of whatever the DV is compared between these diff groups.
Give pros and cons of using an independent groups design .
- more time efficient
- less chance of order effects and demand characteristics
define a repeated measures design
each pp takes part in each condition then compared.
give a pro and con of repeated measures
pp variables controlled, so higher validity
order effects might come into play with demand characteristics.
define a matched pairs design
- pps are partnered with someone with a similar, relevant variable, so pps only take part in one condition
give a pro and con of matched pairs
- pre tests and other matching process may be time consuming
- order effects and demand characteristics are reduced.
define a quasi experiment
- they have an IV that is based on an already existing factor that can’t be changed- eg gender.
give the strengths and limitations of quasi experiments
-cannot determine for sure if IV is what caused change in DV
- have some control, which increases validity.
define a natural experiment
- a type of natural experiment where a researcher uses an IV that is already in existence, but an environmental one that MAY be manipulated, eg drug addicts or left/right handed people.
Give the pros and cons of a natural experiment.
- high ecological validity: since IV cannot be changed, can be applied to real life well.
- lack of control: there may not be control over EVs and confounding variables, leading to low internal validity.
Compare and contrast a NATURAL and QUASI experiment.
- both involve choosing already occurring variables.
- however in a natural experiment, a variable that is an environmental choice is chosen, eg the preference of coffee over tea, whereas in quasi experiments, a natural IV is chosen that cannot be manipulated whatsoever, eg age.
define systematic sampling.
- every nth person from a population being chosen within a sampling frame.
define stratified sampling
- population divided into strata, with pps from each strata being selected using random sampling until a sample size is reached.
give pros and cons of systematic sampling
+: little bias because after interval has been decided, researcher has little to no control over who is selected.
-: time consuming and sampling frame needed.
give pros and cons of stratified sampling
- representative of population, equal proportion of each strata present, easier to generalise.
- time consuming to distribute population into strata, and sometimes categories might be half met, therefore hard to group certain individuals.
What are the BPS ethical guidelines? (4)
- protection from physical and mental harm
- informed consent
- no deception
- confidentiality and privacy.
How do we get around informed consent?(3)
- presumptive consent- other group not in the study asked if it sounds ok
- Prior general consent: consenting to multiple studies, even those that involve deception.
- retrospective consent: asked for after study is done, dueing debrief.
Dealing with deception and protection from harm? (3)
- provide counselling if study was potentially traumatic.
- fully debrief pps
- should be aware that they have right to withhold data.
How do we deal with confidentiality? (2)
- use initials when listing patient specific data
- during debriefing, patients should be made aware that their data will be completely private and not shared with others unless their prior consent is given.