Research Methods

The main research methods used by psychologists are : Experiments Non-experimental methods -Observation -Correlation method -Self report method -Case Study

EXPERIMENTAL METHOD The method used by researchers to study cause-and-effect relationships.

All other variables which might influence the results Manipulates an independent variable (IV) in order to investigate the change in dependent variable. All other variables which might influence the results (called extraneous variables) are controlled. Participants are randomly allocated to the experimental and control conditions. Independent variable (IV): the variable that is manipulated. Dependent variable (DV): the variable that is measured. Experimental group: exposed to the manipulation of the IV Control group. Responses of the control group are compared with the responses of the experimental group.

Laboratory experiment The experiment is carried out in a controlled environment. Disadvantages High levels of control may lead to artificiality of the setting Ecological validity of the study may be a concern Increased risk of demand characteristics and experimenter effects Advantages Variables are easier to control High internal validity Procedures can be easily replicated. Evaluation apprehension, social desirability effects

Field experiment Experimental investigations carried out in natural settings (e.g. homes, school). Involve direct control of the IV and allocation of participants to groups. Disadvantages More difficult to control extraneous variables. Internal validity of the study may be affected. More difficult to replicate Advantages Improved ecological validity. Behaviour studied is more realistic. Decreased risk of demand characteristics

Natural experiment The researcher neither directly controls the IV nor allocates participants to conditions. Makes use of naturally occurring differences in the IV in the pre-existing groups. Disadvantages Degree of control over the IV is less. Difficult to make causal conclusions . Advantages Reduced demand characteristics. Researcher makes use of naturally occurring differences in the IV. Also called quasi experiment.

Non-experimental methods Variables are not deliberately manipulated by the researcher. Allows psychologists to study behaviour in more natural settings. However reduced level of control over the variables make it harder to draw any conclusion concerning cause-effect relationships.

Observational techniques Correlation analysis Self-report techniques including questionnaires and interviews Case studies

Observation A basic research method; behaviour is observed and recorded No deliberate manipulation of variables Observational research can be laboratory or naturalistic. Observes behaviour through behaviour categories Open to subjective bias.

Designing Categories Researcher must define the behaviour he/she observes. Psychologists use behavioural categories to record particular instances of behaviour. For example, observers may use check lists or tally chart for recording observations. Sampling techniques used for observation can be time sampling and event sampling. For example: Deep sleep Active sleep Quiet awake Active awake Crying , fussing STATE OF A BABY DURING A 30-SECOND TIME PERIOD

Correlation method Concerned with the extent of relationships between variables that covary (varies in the same time period) Correlational analysis do not establish causal links. Other variables may influence any measured relationship. As a result, the internal/external validity of the study can be affected.

Self-report measures In this technique, the participants themselves provide information about specific things relating to themselves. (e.g. What they think, believe or do) Questionnaires and interviews- Open or close Interviews can be: Structured interviews can be easily repeated. Unstructured interviews- questions that evolve are dependent on answers given. Main disadvantage of self-report measures: Social desirability bias.

Designing questions When designing a questionnaire, there are some important things to be considered. Type of data. Open ended questions will give qualitative data and close ended questions will give quantitative data. Ambiguity Items and responses should be simple and clearly defined. 3. Double-barrelled questions. Avoid two parts in a single question. 4. Leading questions Avoid questions that lead the participant towards a particular answer.

Case study A detailed study of a particular individual, institution or event. Uses information from a range of sources. Techniques involved to collect data include interview, psychological tests, observations etc. Are generally longitudinal. Difficult to generalise from specific cases.

research designs Aims and hypotheses An aim is a statement of the purpose of a study. Hypothesis is a statement that is testable. A research hypothesis is a general prediction made at the beginning of an investigation , about what the researcher expects to happen. Types of hypotheses Experimental hypothesis/alternative hypothesis predicts that something other than chance alone has played a part in producing the results obtained. Null hypothesis predicts that the results obtained from an investigation are due to chance alone.

Alternate hypothesis can be directional or non-directional. (the direction of a difference or relationship is or is not stated). A directional hypothesis predicts the direction in which results are expected to occur. A non-directional hypothesis does not predict the expected direction of outcome. E.g. of a directional hypothesis. More words are recalled from a list when using rehearsal as mnemonic technique than when no mnemonic technique is used. E.g. of a non-directional hypothesis. There is a difference in the number of words recalled from word lists presented with or without the presence of background music.

Independent group design Experimental designs Independent group design Repeated group design Matched pairs design There are different participants in each group of the experiment Each participant is involved in only one condition of the experiment Each participant is involved in all conditions. i.e. The same participants are used in both the experimental and control conditions. There are different participants in each condition. But there are matched on relevant variables (e.g., age, intelligence etc.). condition.

Control of variables All the variables other than the independent variable that might affect the dependent variable are called extraneous variables. If a variable other than the IV, produces a change in a DV, the results of the study are said to have been confounded.

Variables can be controlled by Counterbalancing Random allocation Extraneous variables can be controlled by keeping them constant or eliminating them altogether.

Pilot studies A small scale trial run of a research study to test any aspects of the design, with a view to making improvements. This should establish whether the design works. Based on the feedback from the pilot study, researcher can make necessary changes. Saves time, effort and money.

Sampling techniques Opportunity sample- uses easily available participants....Biased Volunteer sample-uses volunteers.......Biased Random sample-uses random number technique.....Unbiased Stratified and quota sample – use subgroups within a population and a proportionate number of participants selected. In stratified sampling, random selection of participants leads to more representative sample. In quota sampling, opportunity sampling is used...biased Snowball sample- Uses personal contacts of participants....biased

Issues of reliability Reliability in different research methods. In the context of an experimental research it refers to consistency of results. In observation method, the extent of agreement between observers is called inter-rater or inter-observer reliability. Reliability can be improved through training. In self report methods, the two types of reliabilities are Internal reliability : the extent to which a test is consistent within itself. External reliability: consistency over several different occasions. Inter-interviewer reliability- is the consistency of the outcome of interviews by different interviewers. Two assessment methods of reliability: Split-half method and test-retest method.

Issues of validity Validity –whether the results obtained in a study are true/genuine. Kinds of validity : Internal: Whether the study did test, what it intended to measure. External: the extent to which the results of the study can be generalised to other situations ( ecological validity) and people. Laboratory experiments are not necessarily low in external validity. If low in mundane realism, reduces generalisability of the findings. In observation method, internal validity is affected by observer bias. In self-report techniques, two ways to assess internal validity are Face validity: the extent to which the test looks as if it is measuring what it should measure. Concurrent validity: assessed by comparing the outcome of a test with an already established test on the same topic.

Ethical considerations in psychological research Ethical issues: Informed consent and deception. And Psychological Harm BPS code of conduct identifies four ethical principles 1. Respect -for the dignity and worth of all persons. This includes: Right to privacy, confidentiality, informed consent, and right to withdraw. Intentional deception is acceptable only in some circumstances. 2. Competence- maintaining high standards in research. 3. Responsibility- Protection from harm (physical and psychological) and debriefing. 4. Integrity- being honest and accurate in reporting. Ethical guidelines in conjunction with ethical committees used o assess research proposals. Socially sensitive research-potential social consequences for participants.

Ethical issues with Non-humans Reasons for use of animals in research Offers greater opportunity for greater control and objectivity; When it is not possible to use humans; Physiological similarities. Moral issues- Whether ‘science at any cost is justifiable’? Sentience :Do animals experience pain and emotions? Specieism – Form of discrimination against non-human species. Animal rights- According to Singer, if animal research can alleviate pain and suffering, animal research is justifiable. But Regan (1984) argues that no animal research is acceptable. Do animals have rights if they have no responsibilities? Animal research subject to strict legislation (animal acts; BPS guidelines) ----text page 285 Russell and Birch (1959) proposed the three Rs to be followed in animal research – Reduction (use fewer animals), Replacement (whenever possible use alternative methods, Refinement (used improved techniques to reduce stress.