Research Methods

Research Methods

1. Experimental Methods

   • Aim
     • A general statement of what the researcher intends to investigate.
     • The purpose of the study.
   • Involves the manipulation of an IV to measure the effect on the DV. Experiments may be lab, field, natural or quasi.
   • Hypothesis
     • A clear, precise, testable statement that states the relationship between the variables to be investigated. Stated at the outset of any study.
     • Non-directional hypothesis: does not state the direction.
     • Directional hypothesis: states the direction of the difference or relationship.
   • Variables
     • Independent variable (IV): some aspect of the experimental situation that is manipulated by the researcher, or changes naturally, so the effect on the DV can be measured.
     • Any 'thing' that can vary or change within an investigation. Variables are generally used in experiments to determine if changes in one thing result in changes to another.
     • Dependent variable (DV): the variable that is measured by the researcher. Any effect on the DV should be caused by the change in the IV.
   • Operationalisation: clearly defining variables in terms of how they can be measured.

2. Control of Variables

   • Extraneous variables (EV)
     • any variable, other than the IV, that may have an effect on the DV if it is not controlled.
     • EVs are nuisance variables.
     • EVs do not vary systematically with the IV.
   • Confounding variables (CV)
     • any variable, other than the IV, that may have affected the DV so we cannot be sure of the true source of changes to the DV.
     • CVs vary systematically with the IV.
   • Demand characteristics
     • Any cue from the researcher or from the research situation that may be interpreted by ppts as revealing the purpose of the investigation.
     • this may lead to a ppt changing their behaviour within the research situation
   • Investigator effects
     • Any effect of the investigator's behaviour on the research outcome (DV).
     • This may include everything from the design of the study, to the selection of and interaction with ppts during the research process.
   • Randomisation
     • the use of chance in order to control for the effects of bias when designing materials and deciding the order of conditions.
   • Standardisation
     • using exactly the same formalised procedures and instructions for all ppts in a research study.

3. Experimental Design

   • The different ways in which the testing of ppts can be organised in relation to the experimental conditions.
   • Independent groups design
     • ppts are all allocated to different groups where each group represents one experimental condition..
   • Repeated measures
     • all ppts take part in all conditions of the experiment.
   • Matched pairs design
     • pairs of ppts are first matched on some variable(s) that may affect the DV. Then one member of the pair is assigned to condition A and the other to condition B.
   • Random allocation
     • an attempt to control ppt variables in an independent groups design which ensures each ppt has the same chance of being in one condition as any other.
   • Counterbalancing
     • an attempt to control the effects of order in a repeated measures design: half the ppts experience conditions in one order and the other half in the opposite order.

4. Types of Experiment

   • Lab experiment
     • an experiment that takes place in a controlled environment within which the researcher manipulates the IV and records the effect on the DV, whilst maintaining strict control of EVs.
   • Field experiment
     • an experiment that takes place in a natural setting within which the researcher manipulates the IV and records the effect on the DV.
   • Natural experiment
     • an experiment where the change in the IV is not brought about by the researcher but would have happened even if the researcher had not been there. The researcher records the effect on the DV.
   • Quasi experiment
     • a study that is almost an experiment but lacks key ingredients. The IV has not been determined by anyone and the variables simply exist.

5. Sampling

   • Population
     • a group of people who are the focus of the researcher's interest, from which a smaller sample is drawn.
   • Sample
     • a group of people who take part in a research investigation. The sample is drawn from a target population and is presumed to be representative of that population, i.e. it stands fairly for the population being studied.
   • Sampling techniques
     • the method used to select people from the population.
   • Bias
     • where certain groups may be over or under-represented within the sample selected.
   • Generalsation
     • the extent to which findings and conclusions from a particular investigation can be broadly applied to the population. This is made possible if the sample of ppts is representative of the population.

6. Ethical Issues

   • These arise when a conflict exists between the rights of ppts in studies and the goals of the research to produce an authentic, valid and worthwhile data.
   • BPS Code of Ethics
     • a quasi-legal document produced by the BPS that instructs psychologists in the UK about what behaviour is and is not acceptable when dealing with ppts.
   • Informed consent
     • involved making ppts fully aware of the aims of the research
   • Deception
     • deliberately misleading or withholding information from ppts at any stage of an investigation
   • Protection from harm
     • ppts should not be placed at any more risk than they would in their daily lives.
   • Privacy and confidentiality
     • ppts have the right to control information about themselves, and their right to have any data protected.

7. Pilot studies

   • a small-scale version of an investigation that takes place before the real investigation is conducted, to ensure all aspects work and allow the researcher to make any changes.

8. Blind Procedures

   • Single-blind procedure
     • ppts not told aim of the study and which condition they are in etc, in order to prevent demand characteristics.
   • Double-blind procedure
     • neither the ppt or the researcher who conducts the study know the aim of the investigation, typically used for treatment using placebos.

9. Observational Techniques

   • Naturalistic Observation
     • watching and recording behaviour in the setting within which it would normally occur.
   • Controlled Observation
     • watching and recording behaviour within a structured environment, i.e. one where some variables are managed.
   • Covert Observation
     • ppts behaviour is watched and recorded without their knowledge or consent.
   • Overt Obervsation
     • ppts behaviour is watched and recorded with their knowledge and consent.
   • Ppt Observation
     • the researcher becomes a member of the group who's behaviour he/she is watching and recording.
   • Non-ppt Observation
     • the researcher remains outside of the group whose behaviour he/she is watching.

10. Observational Design

    • Behavioural Catergories
      • when a target behaviour is broken up into components that are observable and measurable.
    • Event Sampling
      • a target behaviour or event is first established then the researcher records this event every time it occurs.
    • Time Sampling
      • a target individual or group is first established then the researcher records their behaviour in a fixed time frame.

11. Self-report Techniques

    • Any method which a person is asked to state or explain their own feelings, opinions, behaviours and/or experiences related to a given topic
    • Questionnaire
      • a set of written questions used to assess a person's thoughts and/or experiences.
    • Interview
      • a live encounter where one person asks a set of questions to assess and interviewee's thoughts and/or experiences. Qs may be pre-set (structured) or may develop as the interview goes along (unstructured).

12. Self-report Design

    • Open Questions
      • Qs for which there is no fixed choice of response and ppts can answer in any way they wish.
    • Closed Questions
      • Qs for which there is a fixed choice of responses determined by the question setter.

13. Correlations

    • A mathematical technique in which a researcher investigates an association between two variables, called co-variables.
    • Co-variables
      • the variables investigated within a correlation, e.g. height and weight. They are not referred to as the IV and DV because a correlation investigates the association between the variables, rather than cause and effect.
    • Positive correlation
      • as one co-variable increases, the other decreases.
    • Negative correlation
      • as one co-variable increases, the other decreases.
    • Zero correlation
      • when there is no relationship between the co-variables.

14. Data Analysis

    • Kinds of Data
      • qualitative aata
        • data that is expressed in words and non-numerical
      • quantitative data
        • data that can be counted, usually given as numbers
      • primary data
        • info that has been obtained first-hand by the researcher for the purposes of the research project.
      • secondary data
        • info that has already been collected by someone else and so pre-dates the current research project.
      • meta-analysis
        • refers to the combining of results from a number of studies on a particular topic to provide an overall view.
    • Descriptive Statistics
      • the use of graphs, tables and summary statistics to identify trends and analyse sets of data.
      • measures of central tendency
        • the general term for any measure of the average value in a set of data
      • mean
      • mode
      • median
    • Graphs
      • scattergram
        • represents the strength and direction of a relationship between the co-variables in correlational analysis.
      • bar chart
        • shows the frequency of each variable represented by the height of the bars

15. Statistical Testing

    • Provides a way of determining whether hypotheses should be accepted or rejected.
    • Sign Test
      • stat. test used to analyse difference in scores between related items.
      • Step 1: allocate + or - (or =)
      • Step 2: count + and -
      • Step 3: S = less frequent sign
      • Step 4: find N and 0.05 on the CV table and if S is less than or equal to the CV, the data is significant.
      • nominal; related
    • Chi-squared
      • nominal; correlation; unrelated
    • Mann-Whitney
      • ordinal; unrelated
    • Pearson's R
      • correlation; interval
    • Related t-test
      • interval; related
    • Spearman's Rho
      • correlation; ordinal
    • Unrelated t-test
      • interval; unrelated
    • Wilcoxon
      • ordinal; related