Psyc - Research Methods

independent variable

the thing that is controlled and manipulated by the experimenter

dependent variable

the thing that is measured by the experimenter. it depends on the independent variable.

extraneous variable

variables other than the IV that might affect the DV

confounding variable

a variable that will always interfere with the effect of the IV - the results in a study can be explained by another factor

participant variables and how they are combatted

they are the differences between individual participants

controlled by random allocation and standardisation

random allocation

when ppts are randomly allocated to a condition in the study

standardisation

controlling the EVs to ensure only the IV is affecting the DV, establishing cause and effect - done by keeping both the conditions the same

situational variables

features of the environmental situation

demand characteristics and how they're combatted

when ppts try to work out whats going on in the experiment and so change their behaviour - their behaviour is no longer natural

combatted with single blind technique

single blind technique

When information about the study is withheld from the participants

order effects and how they're combatted

when ppts improve or worsen in a second test because they have practise/ are tired

combatted with counterbalancing/ random allocation/ randomisation

randomisation

making as many things as possible random

counterbalancing

where half the ppts are in condition a and then b, and the other half are in condition b and then a

investigator effects and how they're combatted

any unwanted influence of the investigator on the outcome

can be combatted with the double blind technique

double blind technique

where the aims of the study are witheld from both the ppts and researchers

aim

what the study is trying to find out - a general statement about what the experiment is looking at that doesnt predict what will happen

hypothesis

a precise and testable statement (or prediction) about the relationship between 2 variables

has 2 types

null hypothesis

a hypothesis that states theres no structural significance between two variables

alternate hypothesis

a hypothesis that suggests there is a structural significance between two variables

can either be directional or non-directional

directional hypothesis

states the way they predict the results will go

typically used in repeated research i.e they have an idea of what they expect to find

non-directional hypothesis

states that there is a difference but not what the difference will be

used in new research when the effects are unknown

Operationalization

making the variables in an investigation detailed and specific

sampling

the process of selecting a representative group of the population

a sample

the group of people who take part in an investigation, the ppts

the more representative the sample, the more generalisable, therefore the more ecologically valid

random sampling

each member of the population has an equal chance of being selected e.g pulling names from a hat

advantages of random sampling

unbiased and representative

helps control ppt variables

disadvantages of random sampling

time consuming

difficult to carry out with large populations

consent is still required

opportunity sampling

a sample containing anyone who is available at the time

advantages of opportunity sampling

quick and cheap in comparison to other methods

disadvantages of opportunity sampling

as it only uses people to are available, isnt representative of society in general

this also makes it biased

volunteer sampling

a sample of ppts who are willing to volunteer

often involves advertising the study e.g newspaper ad

advantages of volunteer sampling

minimal effort

if you place your ad in a certain location youll get your target population

most ethical - consent

disadvantages of volunteer sampling

less representative

volunteer bias

stratified sampling

provides a sample in proportional in terms of characteristics relevant to the population

identify subgroups and then take a random sample from each subgroup

advantages of stratified sampling

provides a very representative sample

disadvantages of stratified sampling

time consuming

expensive

people can still refuse to take part

experimental design

refers to how ppts are allocated to the different conditions in an experiment, 3 types :

independent measures

repeated measures

matched pairs

control condition

the condition of an experiment where nothing is manipulated so that we have a base line to compare our results with

experimental condition

where you manipulate a variable to see an effect

independent group design

different participants are used in each condition of the independent variable

advantages of independent group design

avoids order effects (ppts take part in one condition only)

no demand characteristics

disadvantages of independent group design

needs more ppts

participant variables have more of an effect

repeated measures design

the same ppts take part in each condition of the independent variable

advantages of repeated measures design

fewer ppts needed

less ppt variables

disadvantages of repeated measures design

order effects (can be overcome w/ counterbalancing)

demand characteristics

matched pairs design

where you have two independent groups, which are matched on relevant factors

advantages of matched pairs design

reduces ppt variables due to matching

avoids order effects

disadvantages of matched pairs design

time consuming to find closely matched pairs

impossible to match people exactly

reliability

the consistency of the findings

reliability in sampling methods, theres bias in ...

opportunity, random and volunteer sampling methods

results wont be consistent as the group of ppts will be different

reliability in experimental design, theres bias in ...

independent measures design

results arent consistent as there are participant variables

validity

the extent to which a test measures or predicts what it is supposed to

has two types : external and internal

external validity (and types)

whether our results can be generalised beyond the study

3 types : ecological, temporal + cultural

ecological validity

the extent to which results can be generalised to the real world

temporal validity

whether the results found in todays generation apply to studies 100 years ago

cultural validity

if people from other cultures behave in the same way

internal validity

whether the measures used in the experiment genuinely test what theyre meant to

researcher bias

when the researcher interprets the outcome of a study subjectively

ways to improve validity

reduce bias: EVs, standardisation, counterbalancing, reducing researchers bias etc.

be objective: ensure your variables arent open to interpretation

validity in sampling methods, theres bias in ...

opportunity, random + volunteer sampling

unrepresentative + ungeneralisable results

stratified sampling is proportional to the population and so is the most valid

validity in experimental design, theres bias in ...

repeated measures design

least valid due to demand characteristics + order effects

The British psychological society's guidelines

the BPS set out a code of guidelines:

respect for the autonomy, privacy + dignity of indivs and communities

scientific integrity

social integrity

maximising benefit and minimising harm

consent

the ppt must give permission to take part, knowing the true aims, nature and intended outcomes of the study

right to withdraw

ppts must have the option to leave the study and withdraw all of their data at any time

protection from harm

safeguarding ppts against any physical/psychological harm

confidentiality

not disclosing the identity of ppts

deception

when ppts have been told a false purpose for the research

this is sometimes needed to prevent the ppts acting in an unnatural way - misleading/lying to ppts

privacy

not invading ppts personal lives

debrief

this overcomes issues of consent and deception. The ppts are made aware of the true aims of the study, given the right to withdraw + offered counselling

overcoming ethical issues : informed consent

presumptive consent - gain informed consent from people taking part in the study and assume if these people give consent then your ppts would

overcoming privacy

only conduct the experiment in a public place

limitation

people may consent to things in advance but when it comes to doing the research they may not want to continue

overcoming a right to withdraw

always give ppts the right to withdraw at any point during the research - even if theyve been paid

overcoming protection from harm

not always possible to predict how harmful a piece of research will be so be ready to end early if needed/ offer counselling

overcoming confidentiality

always make a ppt unidentifiable. this means either giving them fake names/ a number

investigating vulnerable and young people

consent must be gained from parents/guardians/someone in a position of trust

experiment

where there is a manipulation of the IV to see what effect it has on the DV, while at the same time trying to control EVs (done in a controlled manner)

types of experiment and where theyre staged:

lab experiment - artificial environment

field experiment - naturalistic environment

natural experiment - examines a naturally occurring V in a real-life environment

key features of a lab experiment

IV is manipulated by the experimenter, DV is measured

all EVs are controlled

ppts know theyre in an experiment, even if they dont know the aim

advantages of lab experiments

can establish cause + effect due to controlled EVs, increasing internal validity

scientific, due to high levels of control

disadvantages of lab experiments

demand characteristics due to ppts being invited

unnatural setting, decreased ecological validity

key features of a field experiment

IV is manipulated by experimenter + DV is measured

less control over EVs due to natural setting

advantages of a field experiment

natural environment, behaviour is natural and ecological validity is high

some cause and effect as some EVs can be controlled

disadvantages of a field experiment

ethical issues due to lack of informed consent

not all EVs can be controlled due to real life environment

key features of natural experiments

occurs in real-life environment

has an IV + DV, but IV occurs naturally and isnt controlled by researcher

advantages of natural experiments

IV = naturally occurring and not manipulated

naturalistic and real environment = natural behaviour + therefore has high ecological validity

disadvantages of a natural experiment

participant variables

cant randomly allocate ppts

EVs are difficult to control

what is an interview and what are its types?

a non-experimental research method that doesnt directly manipulate the IV, it gains info from thoughts and feelings directly from the ppts + data is then analysed

3 types : structured, unstructured, semi-structured

advantage and disadvantage of interviews

+ = allows us to gather info + insight about a ppts feelings + beliefs which is hard to do in an experiment

- = issues w interviewer effects, social desirability bias

structured interviews

predetermined, standardised questions asked in a fixed order

advantages of structured interviews

gathers a lot of info from a large group of people quickly

requires little training

easy to replicate

disadvantages of structured interviews

gathers superficial info from ppts

doesnt allow ppts to answer freely

unstructured interviews

more like a conversation

no set questions

there is a general aim + interviewee is encouraged to expand and elaborate via interviewers prompts

advantages of unstructured interviews

gathers the most in-depth information

disadvantages of unstructured interviews

time consuming

analysis requires training

cant be replicated - not standardised

semi-structured interviews

similar to a job interview

list of qs set in advance but interviewers are also free to ask follow-up qs

advantages of semi-structured interviews

pre-set questions + gives ppts the chance to answer freely

always an in-depth exploration of an area

disadvantages of semi-structured interviews

time consuming to conduct

analysis requires some training

interview schedule

a list of set questions about the study aim

questionnaire

self-report technique that investigates people's beliefs, opinions and attitudes first hand

more flexible than an interview as an interviewer isnt needed to conduct research

diff types of q can be asked