Research Methods Flashcards
cause and effect
psychologists use the experimental method to identify the “effect” one variable has on another variable, in other words does one variable ‘‘cause’’ the other variable to change
being able to conduct research that establishes cause and effect is a key feature of scientific research
In a true experiment, there must be …
a control condition and an experimental condition and participants must be randomly assigned to these conditions
this is so that the researcher can make fair comparisons between the two groups
IV DV controlled
a researcher manipulates the independent variable in order to test its effect on the dependent variable
everything else is kept the same (controlled) between the two conditions
if there is a significant difference in the results of the two groups …
we can conclude that the independent variable caused the change in the dependent variable (cause and effect)
IV
independent variables
a variable that is manipulated by the researcher - or changes naturally
DV
dependent variable
the variable that is measured by the researcher. any effect on the DV should be caused by changes in the IV
in order to test the effect of the IV …
we need different experimental conditions
control condition
provides a baseline measure of behaviour without experimental treatment
experimental condition
the one in which there has been researcher manipulation. this is the condition in which the researcher is particularly keen to see if a difference in behaviour has occurred
operationalism
clearly defining variables so they can be measured
aim
general statement of what the researcher intends to investigate, essentially the purpose of the study
hypothesis
a testable statement predicting the outcome of the study which is made at the start of the study
what are the two different experimental hypothesis
directional (one tailed)
non-directional (two tailed)
directional hypothesis
makes it clear what sort of difference or relationship is between the 2 conditions mainly using words like ‘less’ ‘lower’ ‘more’ ‘higher’
what are the two different kinds of hypothesis and explain them
null hypothesis - this predicts that there will be no difference or relationship
alternate/experimental hypotheses - these predict a difference or relationship and can be directional or non-directional
non-directional hypothesis
used when there has been no previous research to suggest what direction the research will go in or the previous findings have been contradictory
‘will be a difference’ or ‘there will be a relationship’ between the 2 conditions but the there is no direction of the outcome
types of experiments
laboratory experiments
quasi experiments
field experiments
natural experiments
lab experiments
conducted in highly controlled environments
researcher manipulates the IV and records the effects of the DV
participants in a lab experiment can be randomly allocated to conditions
a lab experiment is therefore considered a ‘true’ experiment
strengths of lab experiments
high control over extraneous variables meaning cause and effect can be established
replication is possible due to the high level of control. This also means results can be checked for reliability
limitations of lab experiments
participants are often aware of being tested - possible demand characteristics
artificial environment means it may lack generalisability
investigator effect may occur (unless it is a double blind experiment - this is when both the participants and the researcher conducting the experiment does not know the aims of the investigation)
field experiments
researcher still manipulates the IV and records the effects on the DV but the experiment is conducted in a real life setting
strengths of field experiment
high ecological validity due to being conducted in a real-life setting
behaviour is likely to be more valid & authentic (less demand characteristics)
limitations of field experiments
there is less control over extraneous variables (these will be different depending on the experiment)
it is difficult to replicate them completely because they tend to be less controlled
possible ethical issues if participants are unaware they’re being studied
standardisation
this is using exactly the same procedure for all participants, such as the same environment, instructions and experience
Confounding variable
any variable, other than the IV, that has not been controlled does affect the DV. Therefore we cannot be sure of the true reason for the changes to the DV / differences found
natural experiments
the researcher takes advantage of a naturally occurring IV and the effect it has on the DV
the experimenter has no manipulated the IV directly; the IV would vary naturally whether or not the researcher was interested
the researcher cannot randomly allocate participants to conditions and/or has no control over the IV
this is not a ‘true’ experiment
field experiment: it is the IV that is …
natural, not necessarily the setting
strengths of natural experiment
provides opportunities for research that may not be otherwise conducted due to practical/ethical reasons e.g. does smoking when pregnant lead to behavioural problems in infants
they have high external validity because they involve the study of real-life
limitations of natural experiments
a naturally occurring event may happen, rarely limiting generalisation to other situations
participants may not be randomly, allocated to conditions
Quasi experiments
IV is not something that varies at all - it is simply a difference between people that exists
the researcher records the effects of this ‘quasi-IV’ on the DV
the researcher cannot randomly allocate participants to conditions and/or has no control over the IV
This is not a ‘true’ experiment
example, experiments where the IV is a variable such as age, gender
strengths of quasi experiment
carried out under controlled conditions & share the strengths of a lab experiment
limitations of quasi experiments
participants are aware of being tested - possible demand characteristics
participants cannot be randomly allocated and therefore they may be confounding variables
type of experiment > environment conducted in > independent variable
lab > controlled > controlled
field > natural > controlled
quasi > controlled > naturally occurring
natural > natural > naturally occurring
extraneous variables
any variable other than the IV may have an effect on the DV if it is not controlled
these variables can come from the participant (e.g. age, intelligence), the experimental situation (e.g. noise levels, temperature) or the experimenter (e.g. personality, appearance or conduct of the researcher)
demand characteristics
participants are not ‘passive’ in experiments and they may work out what is going on and change their behaviour to please the experimenter or even act negatively
demand characteristics occur when a participant may receive a ‘cue’ from a researcher or the situation so the participant changes their behaviour as a result
investigator effects
any effects of the investigator’s behaviour (conscious or unconscious) on the research outcome (DV) , this may include everything from the design of the study, to the selection of and interaction with the participants during the research process
ways to minimise extraneous / confounding variables
randomisation
standardisation
variables that need to be controlled
extraneous variables
confounding variables
demand characteristics
investigator effects
randomisation
the use of ‘chance’ in order to control for the effects of bias i.e. in a memory experiment that may involve participants recalling words from a list. the order of the list should be randomly generated so that the position of each word is not decided by the experimenter
Reliability and validity
they can affect the credibility of research findings. psychologists must consider these when designing and conducting research and they are used to assess how good a piece of research is
validity (2 defintions)
how accurate and representative the results are
the degree to which something measures what it claims to
what are the two types of validity
internal validity
external validity
internal validity
concerns whether the results are due to the manipulation of the IV and not affected by confounding variables
external validity
refers to the extent to which the results can be generalised to other settings
what are the two types of external validity
temporal validity
ecological validity
temporal validity
refers to how well we can generalise the results across different periods of time
ecological validity
refers to whether the experimental results can be generalised to other settings, particularly from artificial/controlled settings to real life environment
reliability
how consistent the results are
if the experiment is repeated, will the same or highly similar results occur again?
what are the three different types of reliability
internal reliability
external reliability
inter-observer reliability
internal reliability
refers to the extent to which a test is consistent within itself. for example, if someone was completing a questionnaire measuring high levels of obedience they should have the same score on the questionnaire for it to have internal reliability
external reliability
refers to the extent to which a test is consistent over time. for example if someone achieved 120 on an IQ test if they were tested again in say 8 months time, we would expect them to achieve the same results. this would show the test to have external reliability
inter-observer reliability
refers to the extent to which two or more observers are in agreement on the behaviours they observe. we check for inter-rater reliability by correlating the two or more sets of observations to see if they correlate positively. over or at 0.8 would be high inter-observer reliability and they have consistently observed the same behaviours
experimental design
how the participants in an experiment will be used
three ways a researcher can arrange his/her participants
independent groups
repeated measures
matched pairs
independent groups
when two separate groups of participants experience two different conditions of the experiment
strengths of independent groups
order effects are avoided (when participants become aware of or bored with an experimental procedure)
there are less likely to be demand characteristics because participants only take part in one condition of the experiment and are therefore less likely to pick up on cues
limitations of independent groups
individual differences between groups, otherwise called ‘‘participant variables’’, may affect the results ( what if one group has people who have a naturally higher IQ than people in the other group?) - to deal with this random allocation is used
a larger amount of participants are needed in this experimental design
repeated groups
where all participants take part in both the conditions
strengths of the repeated group
participants variable problems are avoided because all participants take part in both conditions. therefore, it doesn’t matter if they have different IQs or memory abilities because they are kept constant through both conditions
this experimental design requires fewer participants because the same group is re-used
limitations of repeated groups
order effects are very likely to occur; participants may become bored, aware of the aims or tired because they carry out a task twice. they would need to control for this by using counterbalancing
demand characteristics are more likely to occur because participants have been exposed to both conditions of the experiment and therefore may pick on cues or figure out the aim of the experiment
the researcher will need to ensure they have different test materials for condition 1 and 2. for example, they would not be able to use the same list of words in a memory test for both conditions. to control for this they have to use a different set of words but make sure they are of similar difficulty
counterbalancing
am attempt to control order effects in which half the participants take part in condition A then B and the other half take part in condition B then A
For example
Participant 1 = A - B
Participant 2 = B - A
Participant 3 = A - B and so on …
counterbalancing does not remove or prevent …
order effects but attempts to balance out the effects of order between the two conditions
matched pairs
where pairs or participants are first matched on a key variable (i.e. IQ). then one member is assigned to condition A and the other assigned to condition B
strengths of matched pairs
the issue of participant variables is greatly reduced
order effects are totally avoided
demand characteristics are less likely
limitations of matched pairs
it is pretty much impossible to match people exactly on every characteristics unless maybe they are identical twins - and even then, it is usually just matching physical characteristics
it is very time consuming to find lots of people that match each other so closely
example of using matched pairs design in psychological research
bandura et al
bobo doll
in order to control for naturally occurring aggression levels in the children (so it would not confound the DV) he got the children’s parents and teachers to rate their aggression on a 1-5 scale
he then matched the children on their aggression levels so each condition had the same number of highly aggressive children (5), medium aggression (4-2) and non aggressive children (1)
two types of self-report techniques
interviews
questionnaires
structured
structured interviews are made up of pre-determined questions that are asked in a fixed order
this is like a questionnaire but conducted face-to-face (or over the phone) in real time
semi-structured
many interviews are likely to fall somewhere between structured and unstructured
there is a list of questions prepared in advance, but interviewers can follow up answers (like a job interview)
unstructured
an unstructured interview is a lot like a conversation. there is no set questions, but there is an aim that a certain topic will be discussed
the interview will be free-flowing. the interviewee is encouraged to expand on their answers
strength of structured interviews
easy to replicate due to standardised format (increases reliability)
limitation of structured interviews
a problem is that it’s difficult to deviate from the topic or for interviewees to expand on their answers (lacks depth and therefore validity)
strength of unstructured interviews
much more flexible, an interviewer can follow up on points if and when they arise gaining more insight and understanding (increasing validity)
limitations of unstructured interviews
trying to analyse the data can be challenging often because open ended question are used (qualitative data)
there is always the risk of interviewees being untruthful for reasons of social desirability
three different types of interviews
structured
semi-structured
unstructured
questionaires
involve a pre-set list of questions (or items) to which the participants responds through written answers. these are used to assess a person’s thoughts and/or experiences
a questionnaire may be used as part of an experiment to measure the DV. there are different styles of questions that can be designed : open and closed questions
what are the two different styles of questions
open and closed questions
strengths of questionnaires
can be given to a large sample of people and so large amounts of data can be gathered relatively easily. they can also be done without the researcher being present i.e. postal questionnaires
limitations of questionaires
respondents wanting to show themselves in a positive light (social desirability) rather than beinf truthful. or respondents may show ‘response bias’ where they respond in a particular way i.e. always ticking ‘yes’ or answering ‘3’ on a scale of 5
open questions + example
open questions do not have a fixed range of answers and respondents are free to answer in any way that they wish.
open questions tend to produce qualitative data (rich in depth, but difficult to analyse)
for example “Why do you enjoy psychology A level course?”
closed questions + example
closed questions offer a fixed number of responses and produce numerical data by limiting answers respondents can give. they produce qualitative data (easy to analyse, but lack depth associated with open questions)
For example “Do you watch more than 10 hours per week of TV?’… ‘yes’ or ‘no’
or respondents may be asked to rate how often they watch soap opera on TV on a scale of 1 - 5
1 2 3 4 5
1 = never
3 = sometimes
5 = everyday
evaluation of open questions
repondents can expand on their answers, which increases the amount of detailed information collected
open questions can reveal unexpected answers; therefore researchers can gain new insight into people’s feelings and attitudes
they also provide qualitative (non-numerical data) which although may be rich in information, it can be more difficult to summarise and/or detect patterns to draw conclusions
evaluation of closed questions
they have a limited range of answers and produce quantitative data (numerical data). this means the answers are easier to analyse using descriptive statistics (mean, mode, graphical representation)
however, respondents may be forced to select answers that don’t represent their true thoughts or behaviour, therefore data collected may lack validity
what to avoid when designing questionnaires and interviews
overuse of jargon
emotive language and leading questions
double barrelled questions and double negatives
overuse of jargon
technical terms that only those familiar with the field will understand