Methodologies Flashcards
1
Q
Experiments def
A
A research method where the Iv is manipulated by a researcher to measure to measure the effect on a DV
2
Q
Quasi experiment definition
A
a research method where the iV changes naturally and is NOT manipulated by a researcher. The DV is still measured
3
Q
Quasi experiments main features?
A
- involves researching a naturally changing IV
- The effect on the DV of a changing the IV is measured
- can involve a natural experiment (natural setting) or difference study (natural or controlled setting)
- the researcher has no control over allocating ppts to IV groups
4
Q
The two types of quasi experiment are?
A
- natural = Iv is naturally occurring (something that is already happening ➡saint Helena’s - TV Exposure, aggression in kids
- difference = a difference between people that already exists ➡ gender, race, age
5
Q
quasi experiments negatives?
A
- difficult to establish cause and effect relationship between IV and DV as the researcher doesn’t have control over or directly manipulate the IV so there could be an extraneous variable meaning these could be responsible for the effect on the DV
- lacks reliability as there is low control over the research meaning it is difficult to get the same circumstances to repeat the research and check for consistent results
6
Q
Quasi experiment positives?
A
- high ecological validity as there is no artificial manipulation of the IV therefore it is possible to generalise (apply) the findings to behaviour in real life situations
- allows researcher to study areas which would be unethical or impractical to manipulate e.g. comparing sighted to non sighted children. so, valuable for studying certain behaviours
7
Q
Field experiment definition?
A
- researcher manipulates IV and measures effect on DV
- Real life settings (Natural) - school, playground, house
8
Q
Field experiments +
A
- less chance of demand characteristics as ppts may be unaware that they are being studied therefore they are unlikely to pick up on clues so their behaviour is more likely to be natural
- High ecological validity as the experiment is carried out in a real life environment/ setting therefroe it is possible to generalise (apply) the findings to behaviour in real life situations
9
Q
Field experiments -
A
Difficult to establish cause and effect between the IV and DV as the research is carried out in a real life/ natural environment so there’s low control over extraneous variables these could be responsible for the effect on the dv
10
Q
Lab experiments definition
A
- the researcher manipulates the IV and measures the effect on the DV
- Highly controlled environment - not always lab, anywhere that is controlled e.g. classroom
11
Q
lab experiments +
A
High control over extraneous variables as the researcher can control the environment and research - therefore it is possible to establish cause and effect between the IV & DV
- High reliability as they can easily be repeated due to controlled conditions and so it is possible to check for consistent results
12
Q
Lab experiments -
A
High chance of demand characteristics as ppts are aware they are being studied therefore they are likely to pick up on clues as to the nature of the research and may change their behaviour to help/ hinder meaning thieir behaviour is not natural
- low ecological validity as the envir is highly controled and artificial theerfroe it is difficult to generalise the findings to behaviour to real life situations
13
Q
DEFINITION: generalise
A
To apply from one situation or group of ppl to another
14
Q
DEFINITION: External validity
A
the extent to which the findings from the study can be generalised (are valid/ accurate true) outside of the original context in which the study was conducted. Do the results only show how those specific ppts behaved in that setting at that time?
15
Q
DEFINITION: Reliability
A
consistency - if the research was to be repeated and consistent findings were gained, then it woulf have reliability. The researcher could be confident that their findings weren’t a fluke/ one off
16
Q
DEFINITION: Demand Characteristics?
A
any clues which help ppts become aware of the aims of the study causing them to change their behaviour to either help or hinder (‘the screw you effect’) the research so tehir behaviour is not natural
17
Q
DEFINITION: establishing cause and effect
A
being able to say one variable (IV) causes and an effect on another variable (DV)
18
Q
DEFINITION; Ecological validity
A
a type of external validity that refers to the extent to which the findings can be generalised to a real life setting
19
Q
Objective def
A
scientific, black and white
20
Q
subjective def
A
interpretation, bias
21
Q
Representative definition
A
The results can be applied to a wider group of ppl as they are valid and not biased
22
Q
Biased sample def?
A
ALL ppts do not have an equal chance of being selected
23
Q
main features of an experiment?
A
- involve the researcher deliberately manipulating an operationalised IV
- the effect of changing the IV is measured on the DV
- usually contains experimental & control conditions
- the researcher allocated ppts to experimental and/ or control conditions
- aim is to establish cause & effect relationships
- can be conducted in a lab or in the field
24
Q
Quantitative data definition?
A
Quantitative data gathers data in a numerical form which can be put into categories, rank order, or measured in units of measurement. This type of data can be used to construct graphs and tables of raw data
25
quantitative data examples?
- data collected in experiments
- closed answer questionnaires
- Observations - tallies on behaviour checklists
- Content analysis - number of occurrences of cateogories
26
Quantitative data +
+ easy to make comparisons to other sets of data E>G experimental & control conditions, which can be analysed using descriptive and inferential statistic tests- so conclusions are more scientifically objective
+ unlike qual, can be easily replicated and assessed for reliability - numerical data less open to subjective interpretation & so can be measured again
27
qualitative data definition?
data which is descriptive rather than quantified or counted, therefore it is observed or reported rather than measured
28
qualitative data examples?
- case studies - e.g. Bowlby's 44 Juvenile Thieves study
- open answer questionnaires
- observations - description of behaviours observed e.g. Milgram's description of the distress the ppts showed when administering the shocks
- content analysis - converts qual -> quan data
29
qualitative data +
+ may have high validity as qual data provides dtalied information which provides insights into ppts' true thoughts/ behaviours, so meaningful conclusions can be made
+ can represent all acpects of human thought & behaviour as it is descriptive - e.g. feelings towards parents
30
qualitative data -
- diff to make comaprisons across diffrnt groups or [[ts as data is not uniformed and is often very complex, so diff to analyse data
- unlike quan data, qual is diff to replicate and be assessed for reliabilty
31
why is qualitative data diff to replicate?
as descriptive data is open to subjective interpretation and so diif to be measured again y the same or other researchers
32
primary data definition?
data which is collected or observed directly by the researcher from ppts which is specifically for the purpose of the research study
33
primary data examples?
- data collected in experiments
- responses to questionnaires
- observations conducted by the researchers
- interviews carried out by the researcher
34
primary data strengths?
+ the researcher controls the methods & tools used to collect data, so they can ensure it fits the aims and hypothesis of their study
+ as researcher designs the methods used to collect the data, including controlling EVs ect, they can ensure the internal validity
35
primary data limitations?
- more time consuming than using secondary data as researcher deigns study and collects data themselves
- can be difficult, impractical, unethical to collect large sets of data for some behaviours e.g. national crime rates
36
secondary data definitions?
- data which is collected by someone other than the researcher of the study and purpose was for something other than the aims of the study
37
secondary data examples?
- Gov stats
- Meta analysis
- Literature review - e.g. Myers & Diener (1995) study
- Artefacts for content analysis
38
what is meta analysis?
combining data from several different studies
39
2ndry data strengths?
+ quicker than collecting primary data as the researcher has not design study, collected data themselves
+ can analyse data which might be impractical or unethical to collect using primary sources such as large sets of data for some behaviours like national crime rates
40
2ndry data limitations?
- as the researcher does not control the design of the methods used to collect the data, inc, controlling EVs, cannot ensure interval validity
- the researcher does not control the methods and tools used to collect the data, so the data may not fully match the aims & hypothesis of their study
41
what is an observation?
one method for collecting research data. It involves watching a ppt and recording relevant behaviour for later analysis
42
define a ppt observation?
- the researcher observes behaviour whilst part of the group being observed
- data collected whilst being part of the group or situation e.g. joining a cult
43
define a non-ppt observation?
- the researcher is seperate from the group whilst observing their behaviour and does not interfere in any way
- data collected from distance e.g. video camera
44
what is covert observation?
when a ppt is unaware of being observed. the observer may watch through a one- way mirror or be hidden in some other way
45
what is an overt observation?
ppts are aware their beh is being observed so will be aware of the purpose of the research. The researcher is clearly visible to the ppt.
46
behavioural categories def?
dividing a target behaviour (e.g. stress or aggression) into a subset of specific and operationalised behaviours
47
event sampling definition?
an observational technique in which a count is kept of the number of times a certain behaviour (event) occurs
48
time sampling definition?
an observational tech in which the observer records behaviours in a given time frame e.g. recording what is happening every 2 mins
49
strengths of ppt observation?
+ researcher can gain an in-depth understanding of the group's behaviour as they are part of the group and so will not miss important aspects e.g. feelings and motivations
+ it can give access not only to the behaviours of the ppts but also their attitudes, opinions and feelings
+ it enables access to groups that may not allow an outsider to observe e.g. cults- Festinger study
50
limitations of ppt observation?
- the researcher becomes part of the group meaning there is a greater chance of bias in the research findings lowering the IV
- researcher might be overwhelmed w the amount of data and may have difficulty recording the data
51
strengths of non-ppt observations?
+ the researcher is not part of the group so can be more objective thus reducing the chance of bias therefore increasing the IV of the observation
+ as the observer is seperate from the situation, they are more able to manage the amount of data and recording is more straight forward
52
-s of non-ppt observation?
- by not being part of the group, may miss behaviour e.g. feelings and motivation unlike in a ppt observation where the researcher can gain an in-depth understanding of the groups behaviour
BUT sometimes a video camera can replace the observer and this is then analysed afterwards, which can resolve this limitation
- more likely to be covert, thfr there are ethical isues as ppts m feel their privacy has been invaded
53
what is a controlled observation?
the conditions are manipulated by the researcher. This type of observation may be carried out in a lab type situation
54
What is a naturalistic observation?
watching behaviour in a natural envir. No intervention or manipulation of variables e.g. aggression in playground
55
designing observations - steps?
1) decide on the behaviour to be observed
2) decide on the location (controlled/ naturalistic?) (lab/ school) and for how long the ppts be observed
3) overt/covert? ppt/ non ppt?
4) produce behavioural categories
5) Decide on TIME (when and how long will observe for)
6) how to record- tally or rating?
56
when creating behavioural categories ?
make sure the categories u write are SPECIFIC, CLEAR and not open to interpretation. e.g. 'hitting' is too vague. Use punching, kicking, slapping
57
Content Analysis definition?
- an indirect observation of an artefact such as an interview, magazine article, diary. This usually involves changing qual data into quan data by indentifying themes
58
what is an artefact?
object made by a human being
59
why is a content analysis an indirect form of observation?
bc you are not observing ppl directly, but observing them through the artfacts they produce
60
what is meant by the term sampling methods in relation to a content analysis?
what material to sample and how freq (e.g. which TV channels to include, how many programmes, what length of time)
61
identify how CA could generate quan data?
numbers of males and females are counted in the categories
62
identify how CA could generate qual data?
- where e.g.s in each category are described rather than counted
- e.g. when performing a CA of adolescent behaviour from letters in a teen magazine, the researcher would provide quotes from diff letters to illustrate the category
63
main features of a CA? (5)
1. Indirect observation of an artefact - e.g. even if researcher conducted the interview as analysed after interview was done
2. involves coding categories or themes in an artefact
3. turns descriptive qual. data into quan data by counting the occurences of diff themes/ categories
4. can also produce qual. data - may describe
5. artefacts usually sampled through opportunity
64
how to carry out a CA?
AIM- decide on the behaviour and content u want to analyse
⬇
Create BEHAVIOUR CATEGORIES and decide on what materials you will sample and when
⬇
Analyse the content and tally each time you see a behaviour OR describe e.g.s or give quotes from content
⬇
draw conclusions from findings
65
+s of CA?
+ High ecological Validity as it is based on real life communication thfr the findings can be generalised beyond the setting of the study to real life situations
(artefacts not made for psy research)
+ it is easy to assess the R of the findings and conclusions bc the researchers can assess the same materials and use the coding system, to ensure the findings are consistent
+ demand characteristics- ppl who are creating the artefacts dk they're part of psy research
66
-s of CA?
- potential for researcher bias as the judgement abt applying content of an artefact to categories is subjective and a researcher may interpret the content on order to confirm their hypothesis. This lowers the IV
- hard to establish C&E as not conducted under controlled experimental conditions thfr reducing IV
67
what is a pilot study?
dry run
68
what are self report methods?
- methods of gathering data where ppts provide info abt themselves w/o interference from the experimenter.
- they are non exp methods and are often used to investigate experiences/ beliefs/ attitudes/ thoughts/ feelings of the indiv
- questionnaires, interviews
69
+ of self report methods?
+ can investigate ppl's thoughts, feelings, experiences and attitudes which may be diff to study using other methods
70
-s of self report methods?
- ppts may not answer truthfully, thy may give socially desirable answers which would lower the V of the findings
- some ppts may genuinely not l what they think/ feel so the answers they supply may lack IV
- sample may be unrepresentative (ppl who are literate with time available or w restricted sample) thfr collected results cannot be generalised
71
designing a questionnaire? 6 things to consider
1. Type of data u want - quan/ qual?
2. type of ques required - open/ closed?
3. Open questions start w describe/explain/ ect
3. b. closed ques w 'how often, how may or what rating'
4. include distractor ques
5. decide on order - easier q first
6. carry out a pilot
72
questionnaires - remember?
to avoid leading, double barrelled, confusing questions
73
self report methods: type of questions - open?
these are questions which ppts can answer using their own words. They can express their views pf their pwn behaviour and responses tend to include greater detail
GAIN QUALITATIVE DATA
74
Writing open questions - start questions w ?
- describe
- explain
- tell me abt
- give an example of
75
self report methods: type of questions - closed ?
these are questions which mean that ppts responses are fixed for example 'yes' or 'no' rating scales GAINS QUANTITATIVE DATA
76
e.g,s of closed questions?
- Likert scales
- rating scales
- fixed choice option
77
writing closed ques?
- always start questions w;?
- how many
- how often
- on a scale of 1 (strongly disagree) to 5 (strongle agree)
78
questionnaires definition?
- research method which involves collecting data through having ppts respond to written ques, these can be closed/ open, sometimes called surverys
- non exp method
79
what do questionnaires permit a researcher to do?
discover what ppl think and feel, a contrast to observations which rely on guessing what ppl think & feel on the basis how they behave. With a questionnaire, you can ask ppl directly
80
main features of questionnaires?
- used as part of surveys
- data is collected through ppts responding to written questions
- can collect qual data through open que or quan thru closed
- aim is to get a good representation of the target pop using a large sample - thfr making it able to generalise results to the rest of the pop
81
why can't you just say questionnaires are easy to produce?
- this overlooks the fact that they acc take quite a lot of time to design
82
what problems associated w interviews do questionnaires help to overcome?
- respondents may feel more willing to reveal personal/ confidential info than in an interview. In an interview, the respondent is aware that the interviewer is hearing teir answer & this may make them feel self concious and more cautious
83
why are questionnaires high in R?
as can be repeated to check for consistent results unlike a case study which is a one off
84
explain why there may be a problem w the sample who complete questionnaires?
- they r only filled in by literate ppl w free time -> sample likely to be biased
85
+s of questionnaires?
+ as can be filled out by ppts independently, can be easily distributed by post or electronically to large sample groups, thfr u can get a more rep sample and ⬆ Pop V
+ high in R as they can be repeated to check for consistent results unlike a case study which is a one off
86
-s of questionnaires?
- could lead to SDB thfr ⬇ IV
- can be misinterpretation of questions from both the ppt and the researcher whereas in an interview they can ask for clarification
87
questionnaires - issues of IR and how to deal?
- diff ppts may interpret q's diff -> deal w by includig clarification
88
questionnaires - issues of ER and how to deal?
- Ppts answers may be a one-off -> test- retest
89
questionnaires - issues of IV and how to deal?
- SDB - deal w by guaranteeing anonymity
- Face validity - do the ques look like they are actually measuring what they are meant to measure
- Content V
90
questionnaires - issues of EV and how to deal?
- Pop V - the type of people willing to complete questionnaires may not represent other groups of ppl
91
questionnaires - ethical issues?
- confidentiality (assure anonymity)
- invasion of privacy (espec is q personal/ sensitive)
- right to withdraw
92
interviews definition?
- a method of asking questions - in a face to face nature, sometimes it can also be over he phone or computer such as thru skype
- there are 2 types of interview - structured and semi structured
93
structured interviews def?
- all ques standardised b4 the interviews r carried out
- every interviewee will be asked the same ques in exactly the same order
- the interviewer cannot ask any extra ques based on info provided by the ppt
94
2 +s of interviews (in general)?
+ allows ppts to answer ques in greater detail than a written questionnaire - provides rich qual data
+ researcher can observe additional info such as body language, facial expressions or tone of voice - these will verify the validity of ppt's verbal answers
95
2 -s of interviews (in general)?
- compared to questionnaires interviews r time consuming and may limit the number of ppts a researcher may have access to
- as the ppt is usually answering ques face to face, may want to impress researcher so study may lack IV due to SDB compared to a questionnaire
96
what is a - of both type of interviews?
- the interviewers expectations may influence the respondents answers - 'interviewer bias'
- all interviewers must be skilled to prevent interviewer bias as far as possible
97
+s of structured interviews?
+ all ppts get the same ques meaning it's possible to easily compare responses and identify trends and patterns much more easily than using an unstructured interview where ppts get diff ques
+ the questions in a structured interview are standardised which ensures consistency across each interview. This increases both the IR and ER comp to structured semi structured
98
-s of structure interviews?
- researcher cannot deviate from the pre- set ques meaning they cannot follow new lines of enquiry -> may mean don't get as fuller understanding of behav comp to unstructured
- more time consuming & exp as ques are asked face to face and so require 1:1 w a researcher unlike a questionnaire which can be given to lots of ppts to complete
99
what are semi-structured interviews?
- contin some set ques ut also involves each interviewee getting diff ques
- the additional ques are based on the responses of the interviewee so the interviewer can discuss interesting points made by the interviewee
- questions that r asked r more likely to be open ques
100
+s of semi structured interviews?
+ Researcher can allow the person to go into more depth w their responses as ques r based on the responses of the interviewer comp to a structured interview. -> can gain a fuller understanding of ppts behav
+ unlike structured, ques can be rephrased/ presented In diff ways in order that the interviewee can understand them or put in their own cultural frame ->⬆ understanding of the ques may lead to more true answers which ⬆ IV of study
101
-s of semi structured interviews?
- some of the ques asked to each ppt will differ, may mean comparing ppt's responses and identifying trends/ patterns diff comp to structured
- as inconsistency in ques presented to each interviewee, ⬇ IR & might make it diff assess ER through test retest compared to a structured
102
designing an interview - 5 things to consider?
1. Structured/ unstructured?
2. open/ closed ques?
3. decide on interviewer appearance so its same for all ppts to reduce chance of investigator effects
4. how will the interview be recorded (notes/ video?)
5. conduct a pilot
103
interviews - issues of IR and how to deal?
- interviewers may behave diff/ ask ques diff/ read answers diff - deal w by establishing inter-interviewer reliability
104
interviews - issues of ER and how to deal?
Ppt answers may be one off = test - retest
105
interviews - issues of IV and how to deal?
- SDB - deal w by guaranteeing anonymity
- Face V
- concurrent V
106
interviews - issues of EV and how to deal?
Pop V - problem if interviews only conducted in 1 area
107
interviews - ethical issues?
- risk of harm - possible distress caused by sensitive Qs
- Deception - true aims of the Q's may be concealed to collect truthful data
- confidentiality (assure anonymity)
- invasion of privacy
108
case study definition?
an in-depth study conducted into one group or one person. They can be over a long period of time (longitudinal) often use descriptive analysis and often more than 1 methodologies e.g. interviews and observations
109
main features of case studies are?
- in depth study of an individual, group, event
- often over a long period of time
- can be used alongside other techniques such as interviews, e.g. Bowlby's 44 Juvenile Thieves study
- can collect qual and quan data
110
+s of case studies? ⭐ complex interaction and high ecological V
⭐ + the complex interaction of many factors can be studied in contrast w exp where many variable are kept constant, meaning info over looked w other methods is likely to be identified
⭐ + high ecological V as no artificial manipulation of behav so case studies analyse natural behav occuring in real life
111
+s of case studies - longitudinal + only suitable method?
+ often the only suitable method due to the type of behaviour being studied e.g. amnesia as other methods are impractical/ unethical bc u can't make someone have a problem
+ case studies are usually done over a longer period of time than other studies which means it's not just a snapshot of behav, but provides rich detailed data
112
-s of case studies? researcher bias + IV issues?
⭐ + researcher bias - researchers may lack objectivity as they get to k the case more or their knowledge from theories may cause them to overlook aspects of the findings that don't fit w their theory/ hypothesis
+ due to use of retrospective data, may be inaccurate lowering IV. Not always possible to know what the person was like b4 the event and if changes were due to the event or already there
113
-s of case studies ? Pop V & Reliability?
- low Pop V as only conducted on one person/ small group which setting & sit is unique. Thfr, wil be diff to generalise findings to TP lowering EV
- case studies are low in R as they r based on naturally occurring events so diff to repeat study to check for consistent results
114
case study- Genie?
- 13 year old girl in diapers, didn't speak, could hardly walk was kept isolated in a room for 12.5 years
- learnt english words after being found with a linguist but never learnt Grammar
- bc parents rarely spoke to her, parts of brain responsible for Grammar were never stimulated
115
case study - Clive wearing?
- has worst case of Amnesia ever known- 7 sec memory, only recognises wife
116
what is a correlation ?
a non- exp method that measures the strength and direction of relationship or link between 2 co-variables, these can be + or -. There is no IV and DV
117
features of a correlation?
- involves measuring 2 or more co-variables
- does not involve an IV or DV
- can be quickly used to analyse relationships in large amounts of data
- identifies the direction of relationship - +, none or -
- identifies the strength of relationship - weak, moderate, strong
- correlation co-efficient can be calc to identify strength and direction of correlation
118
designing a correlation?
- create an aim for the study and a hypothesis
- clearly operationalise the 2 or more co-variables intended to be measured
- attempt to control confounding variables
- display data on a scatter graph
- use correlation co-efficient to establish the strength and direction of the correlation between co-variables - statistic between +1 and -1
119
correlations - tips on writing aims to a study?
- make sure you identify the study is looking at a relationship, clearly include the co-variables
120
correlations - tips on writing a directional alternative hypothesis to a correlational study?
- identify the operationalised co-variables in the scenario - you will need to include these in any hypothesis
- say that there will be a significant + or - correlation/ relationship between the 2 names operationalised co-variables
121
tips on writing a non- directional alternative hypothesis to a correlational study?
say that there will be a sig correlation between the 2 named operationalised co-variables but DO NOT STATE IF IT WILL BE + OR -
122
tips on writing a null hypothesis to a correlational study?
- say that any correlation between the 2 named operationalised co-variables will be due to chance
123
+s of correlations?
+ can quickly establish if there r correlations between co-variables which will then justify further research to establish causal relationships
+ no manipulation of the IV so is appropriate to use when studying sensitive issues that may raise ethical issues/ inappropriate to manipulate a situation e.g. divorce
124
-s of a correlation?
- diff to establish cause and effect as only a relationship is found between the 2 co-variables. Thfr, other EVs could have been responsible for the relationship found which lowers the IV
- correlations can be misinterpreted by the media and society when a link has been found between 2 variables. Some may assume a conclusion can be made abt the causes for the relationship which can then be misused by the public to support/ contradict an arguement
125
correlation co-efficient definition?
- a statistic ranging from +1 to -1 which indicates the strength (the no.) and direction (+ or -) of a correlation between 2 co-variables. -1 being a perfect neg, 0 being no, and +1 being a perfect pos correlation
126
correlation coefficients- the higher the no. the?
stronger the correlation is (irrespective of whether the correlation is + or -)
127
how to known if the correlation is significant?
- the coefficient must be equal to or greater than the no. in the table of significance to be significant
128
the more pairs of scores u have?
the smaller the coefficient can be
129
continuous variable definition?
a variable that can take any value within a certain range.
130
curvilinear correlation definition?
a non linear relationship between co variables
131
intervening correlations definition?
a variables that comes between 2 other variables, which is used to explain the association between those 2 variables
132
linear correlation definition?
a systematic relationship between co-variables that is defined by a straight line
133
scatter diagram definition?
a graphical rep of the association between 2 sets of scores
134
significance definition?
a statistical term indicating that the research findings are sufficiently strong for us to accept the research hypothesis under test
135
co- variables definition?
the variables investigated in a correlation
136
brain scans?
a technique used to investigate the functions of the brain by taking either 2D or 3D images of the living brain
137
main features of brain scans?
- tech used to investigate the functions of the brain by taking images of the living brain
- they are non-invasive - do not require surgery
- there are 3 main types of brain scans: CAT, MRI, PET
138
CAT?
- Computerised Axel Tomography
- involves a series of X rays and when combined can create 2D or 3D images
- gives 'sliced' images of the brain
139
CT/ CAT +s?
+ good for identifying structural abnormalities in the brain such as tissue damage
+ better quality than traditional x rays
140
CT/ CAT -s?
- they expose ppts to more radiation than traditional x rays and cannot be used on pregnant women
- images are less detailed than MRI scans and cannot show the brain in action like PET scans
141
e.g. of CT?
Weinberger et al (1979) larger ventricle sizes within schizophrenics than a control group
142
MRI scans?
- Magnetic Resonance Imaging - NO METAL!!!!
- uses a magnetic field to change H atom alignment in the brain. The electromagnetic signal is measured to produce detailed 2D and 3D images
143
fMRI scans?
- MRI scans also measure blood n O2 flow in the brain to create a functional image
144
e.gs of MRI scans?
Maguire et al (2000) used MRI scans to demonstrate that London Taxi Drivers had a larger hippocampus
145
+s of MRI scans?
+ provides a more detailed image of soft tissue than CT & PET scans
+ Does not use x rays so less risk of harm than CAT scans - can be used several times in a short period of time on the same ppt
146
-s of MRI?
- They take a long time and can be uncomfortable - ppt not want to continue - 1-1.5 hrs
- cannot show the brain action like PET scans
147
PET scans?
- Positron Emission Tomography
- Administer a slightly radioactive glucose tracers - injection -> might put some ppl off but painless
- the most active parts of the brain use the glucose tracers
- radiation detectors 'see' the radioactive glucose tracers
- can produce still and moving images of brain activity
148
PET e.gs?
used by Raine et al (1997)
149
-s of PET scans?
- more costly, thus less accessible than CAT and MRI scans
- less precise than MRI scans
- radioactivity shouldn't expose ppts multiple time
150
+s of PET scans?
+ can show brain in action unlike CAT and MRI scans - use whilst conducting tasks
+ can produce still and moving images of bran activity
151
+s of brain scans in general?
+ provides a detailed & objective measure of neural activity which has little opportunity for bias and can be seen as reliable
+ unlike post mortem studies, you can investigate neural activity in action (e.g. Raine's study using a continuous performance task) w live ppts
+ PET scans reveal chemical info that is not available w other imaging techs
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-s of brain scans in general?
- scanning machines are exp and thfr often inaccessible to researchers
- some scans e.g. PET can take a long time and be uncom for ppts -> may reduce the no. of ppts who want to take part & would be in approp for claustrophobic ppl
- only a range of activities can be investigated due to limitations of being stuck in a machine
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what is a longitudinal study?
- identifying a gr of ppts at the start and following them over a period of time. Often used in developmental psy
- e.g. used by Kohlberg when researching moral reasoning
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what is developmental psychology?
aims to understand how our behaviours/ attitudes change in diff stages of life
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+s of longitudinal study?
+ helps control for ppt variables so good IV
+ reduced recall bias as ppts are researcher as their life occurs rather than asking them to report on exps from a long time ago
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-s of a longitudinal study?
- time consuming - as studies take years, can lead to sample decreasing as ppl lose touch or drop out -sample attrition
- may be low in pop V due to cohort effect.
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what is a cross-sectional study?
can study the effect of age. This method uses a selection of people to represent the diff age groups you want to compare
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+s of cross-sectional studies?
+ much quicker than longitudial so may be more practical
+ can use larger ppt groups as research is done over a shorter period of time than longitudinal so less chance of study attrition, thfr allowing more rep sample and ⬆pop V
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-s of cross- sectional studies?
- results may b low in IV bc any diffs between diff age groups may be due to ppt variables
- doesn't take into account diffs in generations, the era of each gen may act as a confounding variable and thfr limit the IV of the study
