2.2.2 Methodologies (studies) Flashcards
correlational studies case studies brain scans longitudinal studies cross-sectional studies self-reports (21 cards)
what is a Correlational Study
Used to analyse the relationship or association between two continuous variables (co-variables).
- A scatter diagram/scatter graph can be used to illustrate correlations.
- The closer the coefficient is to 0, the weaker the coefficient
- The closer the coefficient is to 1 (be that +1 or -1) the stronger it is
2 strengths of a CORRELATIONAL STUDY
- Shows both the direction and strength of a relationship which can then be used to make predictions about behaviour.
- Can be used when experiments are inappropriate
2 weaknesses of a CORRELATIONAL STUDY
- Only shows whether there is a relationship; not how or why co-variables are related.
- Difficult to establish cause and effect using a correlation
what is a Case Study
An in-depth study of a unique individual, small group or event.
- Uses many different research methods, such as interviews, questionnaires, or observations in order to get the required depth.
- Most data collected is qualitative, but it can sometimes be quantitative.
- It is a holistic study and is usually longitudinal
2 strengths of a CASE STUDY
- Produces rich qualitative data which is of high ecological validity because it is a study of real-life situation.
- Allows researchers to study cases they couldn’t practically or ethically manipulate in an experiment
2 weaknesses of a CASE STUDY
- Researcher bias; researchers can become too involved and lose their objectivity.
- It is difficult to generalise findings beyond the individual/group studied; the sample is too small > low population validity
what are Self-Reports
Methods that involve the participant reporting information about themselves.
- They can include interviews, questionnaires, inventories, diaries
2 strengths of SELF-REPORTS
- Self-reports offer an insight into why people behave as they do, so there is less need for researchers to guess reasons for behaviours.
- Qualitative information can be gathered
2 weaknesses of SELF-REPORTS
- Possible risk of social desirability bias.
- People may not be able to recall accurately, especially if self-report method asks for details over an extended period
what is a CAT Scan
A set of x-rays combined together to form 2D or 3D images of the area of the brain that is being scanned.
Before the x-rays are taken, radioactive dye is injected into the patient then they are placed in the cylindrical CAT scan machine.
CT scans use a series of X-ray beams passed through the head, creating cross-sectional images of the brain showing the structure, but not the function
2 strengths of a CAT SCAN
- High quality images, better than those produced by x-ray alone.
- They can reveal structures in the brain that appear abnormal, e.g. tumours
2 weaknesses of a CAT SCAN
- Only provide a researcher with the structure of the brain, not the electrical activity of the brain.
- Exposure to radiation: the more detailed the scan is, the more radiation an individual is exposed to
what is a PET Scan
The patient is given a radioactive glucose (sugar).
Areas of the brain that appear to be more active are the areas which require the most glucose.
The detectors in the scanner can highlight the most active areas of the brain, allowing an in-depth image of what the brain activity is like
2 strengths of a PET SCAN
- Only PET scans allow researchers to see chemical activity in the brain.
- Useful for psychological research as they look at more active brain areas
2 weaknesses of a PET SCAN
- Costly to run and maintain, meaning there is limited availability for research.
- Not as precise as scans such as an MRI
what is a Longitudinal Study
A study conducted over a long period of time.
- Participants are assessed on two or more occasions as they get older.
- This allows the researcher to investigate any long-term effects (e.g. how memory gradually decreases with age)
2 strengths of a LONGITUDINAL STUDY
- The same person is tested numerous times so participant variables are controlled.
- Developmental trends can be spotted as tests are repeated at regular intervals
2 weaknesses of a LONGITUDINAL STUDY
- High attrition rate because the research takes so long.
- Participants are more likely to be aware of the aims of the study so may show demand characteristic
what is a Cross-Sectional Study
One group of participants representing one section of society
are compared with participants from another group
e.g young people being compared to old people
2 strengths of a CROSS-SECTIONAL STUDY
- Relatively quick and cheap because participants only need to be tested once for comparisons.
- Participants are easier to obtain because there’s less pressure for them to take part, compared to having to stick with a long-term longitudinal study.
2 weaknesses of CROSS-SECTIONAL STUDY
- Difficult to determine why there are differences between the two cohorts as participants cannot always be asked about the differences.
- Data collected is from a snapshot in time, so it’s harder to identify and analyse developmental trends in these studies
