If you are studying A Level Psychology, you will most likely of come across research methods. Research methods refer to the ways psychologists investigate psychological phenomena. Psychological phenomena can refer to observations that explain certain aspects of human thoughts, behaviours and emotions. These theories help psychologists make predictions for future human behaviours or events that may occur.
Research methods includes experiments, observations, self-report techniques, case studies and longitudinal studies.
For psychology a-level (AQA, CIE and Edexcel), you are required to understand sampling (how psychologists choose participants to research), types of data (the information collected), research design and methods (how research is set up and the tools used to collect data) and data analysis (how psychologists make sense of the data collected).
Types of sampling – How psychologists choose participants to research
Volunteer sampling
Volunteer sampling is when participants volunteer their time to participate in research. This may be achieved through advertisements e.g. flyers. This is a time-efficient, cheap and simple way to recruit participants. On the other hand, this sampling method may be criticised for potential bias as participants may not be representative of the wider population.
Systematic sampling
This is when every nth item from a list is used to create an evenly distributed sample. It is easy to use, cost effective and provides a representative sample so enhances the study’s validity. However if there is a pattern in the population then this is at risk of bias.
Stratified sampling
This is a method of sampling where a population is divided into subpopulations (strata) based on characteristics. This method has increased accuracy and is therefore representative of the wider population. However, it may be time-consuming and complex to implement.
Random sampling
This refers to a group of participants being chosen from a larger set of individuals with the same probability e.g. pulling names from a hat. This reduces bias in recruitment as there is equal chance of being chosen, which enhances representativeness. On the other hand, it can be difficult to acquire information for the larger group and there is risk of sampling errors.
Types of data – The information collected
Quantitative data refers to numerical data or measurements collected e.g. height, test scores or ratings. This may be collected through more scientific methods e.g, experiments.
Qualitative data concerns words or descriptions e.g. feelings and opinions. This can be collected through interviews or questionnaires.
Research design and methods – how research is set up and the tools used to collect data
Experimental design
Experiments test a cause and effect relationship by changing the independent variable and observing how this affects the dependent variable. Experiments are typically carried out in controlled environments e.g. labs and produce quantitative data. They also can include an experimental group (the change group) and a control group (no change). Advantages of this approach include control over extraneous variables to enhance internal validity, replicability which enhances reliability and identifying cause and effect relationships. Disadvantages include research being costly, time- consuming and the artificiality of labs not being generalisable to the wider context.
Observational design
Observations can be covert (participants are unaware they are being observed) or overt (participants are aware). Psychologists will watch and record behaviour either in real-life contexts e.g. a classroom or in a controlled environment e.g. a lab. Advantages of this approach is observing behaviour in natural settings produces realistic results, low cost and also time-efficiency. Disadvantages include observer bias where participants may change behaviour when they are being watched and confounding variables as it may be hard to control extraneous factors.
Self-reporting
Self-report refers to individuals answering questions about their own behaviour, feelings or thoughts. This may be through questionnaires, surveys or interviews. Advantages of this include reaching large samples e.g. widespread surveys which enhances generalisability and limited researcher bias. Disadvantages include social desirability bias and recall issues when recalling experiences or situations.
Case studies
A case study is a focused, in-depth study of an individual, group or context. Psychologists will use different methods over a period of time e.g observation followed by an interview. Advantages include producing an in-depth understanding of complex phenomena and a focus on real-world situations that may be difficult to examine through other research methods. Disadvantages include limited generalisability due to small sample size and can be time-consuming.
Longitudinal studies
A longitudinal study is when an individual or group of people are researched over a longer period of time e.g. a year. Psychologists typically use this method to investigate phenomena and change overtime or to understand the long-term effects of behaviour or experiences. Advantages include the ability to identify changes overtime and establishing cause and effect relationships. Disadvantages include being time-consuming and the potential for participant drop out.
For more information on research design and methodology:
Pearson Edexcel Specification, Section 9.1
AQA Specification, Section 3.2.3
Analysis – how psychologists make sense of the data collected
Quantitative analysis (descriptive statistics and inferential testing)
Mean, median and mode
These are measures of central tendency, used to describe the typical value of a set of data. The mean is the average of all values, calculated by adding them together and dividing them by the number of values there are. Median is the middle number when data is ordered from lowest to highest. The mode is the most commonly occurring value.
Correlations
Correlations are either positive, negative or null, to see how two variables relate.
Inferential testing
Another quantitative analysis tool may also be significance/inferential tests. This includes chi-square tests, which are used to test the relationship between two categories. T-tests are used to test if the mean of a group differs from another group.
Qualitative analysis
Content analysis
This refers to analysing textual data to identify themes and patterns by turning qualitative data into quantitative.
Thematic analysis
This is used to identify and interpret common themes e.g. from transcripts from interviews or survey responses. The patterns of themes are coded and reported.
For more information on analysis:
AQA Specification, Section 3.2.3.2
Cambridge Specification, Page 23
Pearson Edexcel, Appendix 6 (quantitative analysis)
For the full syllabus and further information.
