Psychology Research Methods (A2)
Research Methods (A2)
Correlations
• Correlation: a mathematical technique where a researcher investigates a relationship
between two co-variables
o The two co-variables are continuous variables, not discrete
• Correlational data is plotted on scattergrams, where each axis represents one of the co-
variables investigated
• A correlation coefficient is a number between -1 and +1 that represents the direction and
strength of a relationship between co-
variables
o +1 is a perfect positive
correlation, and -1 is a perfect
negative correlation
o The closer the coefficient to +1 or
-1, the stronger the relationship
between the co-variables
o The closer to zero the coefficient
is, the weaker the relationship
• The correlation coefficient can be
calculated using an inferential statistical
test
• Note that weak correlations may still be statistically significant; it depends on the sample
size
Case Studies
• Case study: an in-depth investigation, description and analysis of a single individual, group,
institution or event
• Case studies usually, though not exclusively, collect qualitative data
• A case history will be collected, using interviews, observations, questionnaires etc.
• Case studies may include experimental or psychological testing to assess what they are or
are not capable of. This may produce quantitative data
• Tend to be longitudinal
• May involve gathering additional data from family and friends of the individual
Evaluation of Case Studies
• Provide rich, detailed insights that may shed light on unusual or atypical behaviour
o May be preferred to experiments of questionnaires that would produce more
superficial data (viewing the surface of the issue but no depth or detail)
• May contribute to our understanding of normal behaviour, e.g. the case study of HM
demonstrated ‘normal’ memory processing and the separation of the STM and LTM
• May generate hypotheses for further study
• May lead to the revision of an entire theory if it is contradictory
• Generalisations are not possible as the sample size is so small
• The information that makes it into the final report is based on the subjective selection and
interpretation of the researcher
• Personal accounts from the participants and their family and friends may be prone to
inaccuracy and memory decay, especially if the stories are from childhood
Research Methods (A2)
Correlations
• Correlation: a mathematical technique where a researcher investigates a relationship
between two co-variables
o The two co-variables are continuous variables, not discrete
• Correlational data is plotted on scattergrams, where each axis represents one of the co-
variables investigated
• A correlation coefficient is a number between -1 and +1 that represents the direction and
strength of a relationship between co-
variables
o +1 is a perfect positive
correlation, and -1 is a perfect
negative correlation
o The closer the coefficient to +1 or
-1, the stronger the relationship
between the co-variables
o The closer to zero the coefficient
is, the weaker the relationship
• The correlation coefficient can be
calculated using an inferential statistical
test
• Note that weak correlations may still be statistically significant; it depends on the sample
size
Case Studies
• Case study: an in-depth investigation, description and analysis of a single individual, group,
institution or event
• Case studies usually, though not exclusively, collect qualitative data
• A case history will be collected, using interviews, observations, questionnaires etc.
• Case studies may include experimental or psychological testing to assess what they are or
are not capable of. This may produce quantitative data
• Tend to be longitudinal
• May involve gathering additional data from family and friends of the individual
Evaluation of Case Studies
• Provide rich, detailed insights that may shed light on unusual or atypical behaviour
o May be preferred to experiments of questionnaires that would produce more
superficial data (viewing the surface of the issue but no depth or detail)
• May contribute to our understanding of normal behaviour, e.g. the case study of HM
demonstrated ‘normal’ memory processing and the separation of the STM and LTM
• May generate hypotheses for further study
• May lead to the revision of an entire theory if it is contradictory
• Generalisations are not possible as the sample size is so small
• The information that makes it into the final report is based on the subjective selection and
interpretation of the researcher
• Personal accounts from the participants and their family and friends may be prone to
inaccuracy and memory decay, especially if the stories are from childhood
