Research Methods Flashcards
what is sampling
- the process of selecting participants from the target population to take part in research
what is the target population
who you want to do the research on
why should samples be as representative of the target population as possible
the study will try to be generalised back to the target population so participants samples should be as representative as possible
why should sample size be sufficient size
to eliminate the impact of any anomalies
what is random sampling
when every member of the target population has an equal chance of being selected
- so they are chosen entirely by chance
what is an example of random sampling
- putting names into a hat
what is an advantage of random sampling
- in large numbers, provides the best chance of an unbiased sample of a target population as everyone has equal chance
what is the disadvantage of random sampling
- the sample may not be representative of target population as pp may not be matched for ability, gender, background etc. increasing the chance of anomalies
what are the 4 types of sampling
- random sampling
- stratified sampling
- systematic sampling
- opportunity sampling
what is stratified sampling
- when the target population is broken down into subcategories that represent the target population, then pp are selected in the proportion they occur in target population
if a target population of year 12 student consisted of 75% female and 25% male what would the sample of 20 be (stratified sampling)
15 female
5 male
what is the advantage of stratified sampling
- this is a representative sampling method as everyone in the target population would be represented in the pp being sampled
what is the disadvantage of stratified sampling
- can be time consuming because the subcategories have to be identified and their proportions calculated
what is systematic sampling
- when a consistent system is in place for who is selected
what is an example of systematic sampling
eg every 4th person
what is a problem with systematic sampling
- it does not give an equal chance of selection
what is an advantage of systematic sampling
- assuming the list order has been randomised, this method offers an unbiased chance of gaining a representative sample
what is the disadvantage of systematic sampling
- if list is not randomised or a narrow selection of target population, then unrepresentativeness may be present
eg every 4th person was male
what is opportunity sampling
- involves selecting pp that are around and available at the time of the study
what is an example of opportunity sampling
- first 20 students at school
what is an advantage of opportunity sampling
- quick, convenient and often the most economical method- therefore quite common
what is a disadvantage of opportunity sampling
- likely to find an unrepresentative sample if only sampling at a particular time or in a particular place
e.g first 20 students not likely to represent students who live far away
what are the strengths of using a correlation
- initial relationship can be discovered which might not have been realised prior because a flexible design like correlations can lead to new variable relationships
- the same people are providing both sets of data so it is repeated measures, so data will nit be affected by individual differences therefore results are not affected by participants variables
what are the weaknesses of using correlations
- correlational designs only indicate a relationship between 2 variables there is no cause and effect identifies as there is no IV or DV
- the measures might not provide valid data- time in therapy is a clear measure but the benefit of therapy are not easy to quantify
what is a correlation coefficient
a measure of the strengths of correlation
what is the spearman test
-1 0 +1
what correlation is +1, -1 and 0
+1 is strongest positive correlation
-1 is strongest, negative correlation
0 is typically no relationship
what does casual relationship mean in term of correlation
- researches using this does not establish a cause and effect relationship
what happens in a positive correlation
- one variable increases as the other variable increases
eg time spent studying increase exam marks
what is a negative correlation
- one variable increases as the other decreases
eg. more time watching tv decrease exam marks
what does the correlation show if there is no relationship
- correlation may state there is no meaningful correlation between variables- it is not linear
are a negative and positive correlation linear
yes
what does a non linear relationship show(correlation)
a correlation that reaches a point, then changes direction
- can be dipped or peaked curves
x
x x
x x
what is a correlation
a measure of the relationship between 2 variables
what will the hypothesis of correlations be
will be about the relationship between 2 variables
what does a scatter diagram show
will show whether a correlation is positive or negative or neither
how is a scatter graph generated
2 scores from each participant or variable generates a point on a graph
what can be drawn on a scatter graph
a line of best fit- if there is a relationship, close to as many points as possible
where are anomalies located on a scatter graph
are points furthest away from the line of best fit
what does it mean if it is not clear where the line should go
there is no relationship
what is quantitive data
numerical data
what is an example of quantitive data
time or words recalled
what is good about using quantitive data
- provides info that is easy to analyse statistically and is reliable
why is quanitive data criticised
- associated with the scientific and experimental approach and criticised for not providing in depth description
what are the strengths of quantitive data
- scientific objectivity- can be interpreted with statistical analyse and because it is based on maths it is viewed as scientifically objective and rational
- reliability- based on controlled, structured and replicable research procedures so the result of studies can be tested for accuracy through repeating the investigation
what are the weaknesses of quantitive data
- validity- does not usually take place in natural settings, so they are limited when considering real life behaviour
- meanings- data driven research does not allow pp to explain the choice behind their behaviour in a study, so detail and human behaviour are lost
what is qualitative data
- generate data that describes meaning and experiences (word)
how does a qualitive method study behaviour
- in a natural setting
what are the strengths of qualitative method
- validity, results give researchers a richer understanding and an insiders view of reasons for behaviour- allows researcher to find issues that are often missed from quantitive data
- representative, is representative of the real life context that human behaviour takes place in realistic view
what are the weaknesses of qualitive methods
- subjective, way in which research takes place means the data is often subjective and can be open to biased interpretation of meaning
- reliability, context, situations, events and conditions that many qualitative methods documents cannot be replicated to real extent- results cannot be retested for accuracy, generalises to a wider context are weak as its a small sample
what are the 3 experimental designs
- matched pairs design
- independent measures design
- repeated measures design
what is an experimental design
concerns the way that pp are allocated to conditions in a research study
what is an independent measures deign
- if 2 groups in an experiment consist of different individuals
eg if we are trying to discover whether girls are less aggressive than boys- then we will have 2 groups, boys and girls
what are the strengths of an independent measures design
- no demand characteristics so pp cant compare different conditions of study and are unlikely to guess aim
- order effects like practice, fatigue and boredom are avoided as pp only do one condition in the study
- same test can be used for both groups with only IV manipulated so can be good way to test differences
what are the weaknesses of independent measures design
- pp variables differ, which could become confounding variables
- statistical test can be less reliable- there is more variation between 2 conditions
- you have to find twice as many people- could be time consuming and uneconomical
what is a matched pairs design
- match every subject in one group with a very similar person in the other group
what are the strengths of matched pairs design
- pp variables like IQ, education and culture etc are controlled because people are paired on similar traits
- order effects are avoided- pp take part in only one condition
- demand characteristics are less of a problem because pp only take part in 1 condition and are not gonna guess the aim
what are the weaknesses of matched pairs design
- pp variables can never be perfectly matched so cannot completely control this
- matching pp is time consuming and not always effective-close matches can be hard to find
- if 1 person drops out, then whole pair ahs to be dropped from data-can be expensive if have to be replaced
what is a repeated measures design
- when the researcher uses the same pp in each conditions-test pp two or more times
what are the strengths of a repeated measures design
- pp variables do not differ between conditions as the pp are the same people
- statistical test can be more reliable-there is limited variation between 2 conditions
- you only need 1 group of pp so it is not time consuming and is economical
what are the weaknesses of a repeated measures design
- demand characteristics, pp can compare the different conditions of the study and more likely to guess the aim
- order effects like practice, fatigue and boredom can occur-pp do 2 or more conditions in the study
what is the mode
the most common
1,1,1,2,2,3= 1
what is the mean
add up all numbers/ how many numbers
1,1,2,3= 1+1+2+3/4= 7/4
what is the median
middle number
1,2,3,5,6= 3
1,2,3,5,6,7= 4
what is the range
biggest value- smallest value
what is a case study
- involves studying an individual or small group, usually over a long period of time
what data does case studies mainly involve
- qualitative data from interviews- gives richness and detail
what is often studied in case studies
- unique circumstances
eg a brin damage study can provide knowledge about what a particular part of brain does
how can case studies gather data
use different ways- eg questionnaires, experiments, interviews
how long do case studies take
usually longitudinal- take place over a longer period of time
- so researcher can see how behaviour changes over months
what are the strengths of case studies
- capable of providing interesting and rich, detailed data about people giving them strong validity - hard to use detail using other research methods
- can look at rare situations which are difficult to find, a case study is a way of gathering lots of info about a rare occurrence
- researchers spend a lot of time with pp, so a relationship may occur so should recognise when being to intrusive, often use initials of pp so improves confidentiality
- triangulation means researchers can combine methods(interviews etc) to gather valid, qualitive data
what are the weaknesses of case studies
- might cause bias as researchers are spending lots of time with pp so cause bias in what data is recorded- possible subjectivity in the data
- focus on only one or few people means its difficult to generalise the findings as not representative of target population therefore lack reliability as effect of any anomalies on data cannot be limited by sample size
- case study involves lots of retrospective data, pp may have to remember events from their past- memory errors may influence what they say
