Case Studies, Longitudinal etc.

Case studies

Case studies are very detailed investigations of an individual or small group of people, usually regarding an unusual phenomenon or biographical event of interest to a research field. Due to a small sample, the case study can conduct an in-depth analysis of the individual/group. It is also important to not that case studies can also focus on typical or mundane things such as childhood memories.

Case studies will tend to collect qualitative data. A researcher will collect a history of information on the individual and they can do this through a variety of methods including interviews, observations, questionnaires and psychometric tests.

Case studies tend to take place over a long period of time where data is collected many times over this period. The data collection may also involve gathering information from the individuals family, friends and professionals connected to the individual, such as teachers or doctors.

One case study that you will already be familiar with is the case of Little Hans that was published by Freud. This case study was used to support his theory on the unconscious mind and the oedipus complex.

freud-and-hans

We also covered the case study of HM in the memory unit of the course.

Another famous case study that isn’t covered on the specification, but you may want to look into, is the case study by Thigpen & Cleckley (1954). These psychologists studied a young woman called Eve who was one of the first cases of multiple personality disorder. You can read up on it using the link below:

http://www.holah.karoo.net/thigpenstudy.htm

 Strengths:

  • Studying abnormal psychology can us a huge insight into things in which we otherwise would have very limited understanding. For example the case of Eve with multiple personality, which you can watch in the video above. 
  • The detail collected on a single case may lead to interesting findings that conflict with current theories, and stimulate new paths for research.
  • Case studies create opportunities for a rich and detailed data. The depth of analysis can increase validity (i.e. providing an accurate and exhaustive measure of what the study is hoping to measure).
  • Researchers can build a relationship with the participant and therefore collect data that is possibly more valid as they feel more comfortable to be honest around the researcher.

Weaknesses:

  • There is little control over a number of variables involved in a case study, so it is difficult to confidently establish any causal relationships between variables.
  • Case studies are unusual by nature, so will have poor reliability as replicating them exactly will be unlikely.
  • Due to the small sample size, it is unlikely that findings from a case study alone can be generalised to a whole population.
  • The case study’s researcher may become so involved with the study that they exhibit bias in their interpretation and presentation of the data, making it challenging to distinguish what is truly objective/factual.
  • In addition, case studies may have ethical issues in terms of privacy. This is because they tend to study unusual topics of behaviour and the researcher will spend a lot of time with the participant. 

Longitudinal Research

Longitudinal research is a type of correlational research that involves looking at variables over an extended period of time. This type of study can take place over a period of weeks, months, or even years. In some cases, longitudinal studies can last several decades. Longitudinal research tend to have much larger samples in comparison to a case study which would have one individual or a small group of people. They tend to collect quantitative data due to having larger samples. 

Strengths:

  • For many types of research, longitudinal studies provide unique insight that might not be possible any other way. This method allows researchers to look at changes over time. Because of this, longitudinal methods are particularly useful when studying development and lifespan issues. Researchers can look at how certain things may change at different points in life and explore some of the reasons why these developmental shifts take place. For example, consider longitudinal studies that looked at how identical twins reared together versus those reared apart differ on a variety of variables. Researchers tracked participants from childhood into adulthood to look at how growing up in a different environment influences things such as personality and achievement. Carrying out a snapshot study would lack validity in trying to gain long term development and change. 
  • Since the participants share the same genetics there is no issue of individual differences. Unlike a cross-sectional study which would be comparing different sets of individuals of different ages. Longitudinal research doesn’t have the issue of this extraneous variable. 
  • The collection of quantitative data can make it easy to analyse when looking at the development of behaviour over time. And also make data collection quicker.

Weaknesses:

  • Longitudinal studies require enormous amounts of time and are often quite expensive.
  • Another problem is that participants sometimes drop out of the study, shrinking the sample size and decreasing the amount of data collected. This is known as attrition.  Participants might drop out for a number of reasons, like moving away from the area, illness, or simply losing the motivation to participate. If the final group no longer reflects the original representative sample, attrition can threaten the validity of the experiment. Validity refers to whether or not a test or experiment accurately measures what it claims to measure. If the final group of participants is not a representative sample, it is difficult to generalise the results to the rest of the population.

Snapshot research

A snapshot study takes place at just one point in time, usually with a larger group of participants. It can collect both quantitative and qualitative.

Strengths:

  • Fast way of collecting data as you are only collecting data at one point in time.
  • Typically a larger sample and therefore it will be more generalisable. Also, because it is at one point in time, attrition rates are less likely.
  • Good way of obtaining evidence before a costly and time consuming longitudinal study.
  • Data is most likely quantitative, so it is easy to analyse the data
  • Tends to have high reliability due to using experiments and questionnaires

Weaknesses:

  • Lacks depth and detail in the data due to tending to collect quantitative data
  • It does not capture how behaviour can change over time. Therefore it may not reflect behaviour in the long-term.

Meta-analysis

A meta-analysis is the process where researchers collect and collate a wide range of previously conducted research on a specific area. This research is then reviewed together in order to provide an overall conclusion of a specific topic within psychology.

For example, van Ijzendorn used a meta analysis of 32 studies, to see if there were any cultural differences of the types of attachment. He found that the UK had the highest rates of secure attachment, and that Germany had the highest rates of insecure avoidant attachments.

Strengths:

  • Increases the validity of the conclusions drawn as they’re based on a wider range of research.
  • Meta-analyses can help to direct future research.

Weaknesses:

  • Research designs in studies can vary so they are not truly comparable.
  • The researchers may have an element of bias, as they are still choosing which studies to include as part of their meta-analysis.