Psychology, psychologists and research methods

• Researcher always intervenes directly in a situation by manipulating at least one variable

• Variable is anything that can be measured and that can change such as age, weight, response times

• True experiment has 3 key features: Independent variable (IV)
                                                                    Dependent variable (DV)
                                                                    Controlled variables
• researcher formulates hypothesis that IV will affect DV
• in simple form of an experiment, researcher manipulates the IV to produce a change in the DV
• variables must be held constant to ensure the change produced is not due to confounding variables 

Principle of good experimental design is the random allocation of the groups in a study

Advantages of the experimental method:

• By holding variables constant between groups, experimenter able to establish a cause-and-effect relationship between the IV and the DV
• Use of experiments allows researchers to force the pace of research because they don't have to wait for natural events to reproduce the appropriate scenario needed to investigate a particular issue
• experiment generates quantitative data which can be analysed using inferential statistical tests
• once the data from research has been obtained and analysed, it can be generalised to the rest of the population

  Disadvantages:

• many investigations have participants who reflect an overrepresentation of males and of spcific cultures
• participants usually know they're taking part in an experiment
• not always possible to carry out an experiment as it may be inappropriate or unethical to do so  

Laboratory experiments

Summary:

• provide highest level of control over variables
•  used widely in psychology
• important to think carefully about the design of the study when reading an account of a lab experiment

Advantages:

• replicability of procedures: lab experiment can easily be repeated by other researchers to see if similar results are obtained. When results are repeated, confidence is increased in them.
• Sophisticated measuring and recording equipment is used
• there is a high level of control over variables

Disadvantages:

• loss of validity: experimental situation becomes artificial and different from real life situations
• demand characteristics: occur when participants try to make sense of situation they find themselves in and adjust their behaviour accordingly 

Summary: 

• investigations carried out in natural environment of those being studied
• experiments attempt to improve realism of research

Advantages:

• Improved ecological validity: artificiality of the laboratory experiment is avoided, helps eliminate the main critism that findings can't be generalised to real life situations
• reduction of demand characteristics: participants may be less conscious they're taking part in a research study hence reduction of demand characteristics

Disadvantages:

• establishing controls: difficult to establish a high level of control in a field experiment 
• generalizing to other situations: although realism is high, results can't be generalised to situations that differ from the one in which the expt took place

Summary:

• researcher makes use of naturally occurring differences in the independent variable
• means researcher doesn't directly control the IV
• approach is best described as a quasi-experiment
• some purists regard it as a non-experimental study

Advantages of natural experiments:

• reduction of demand characteristics: participants are less conscious they are taking part in an experiment
• lack of direct intervention: experimenter doesn't intervene directly in the research situation

Disadvantags of natural experiments:

• loss of control: overall degree of control exercised by the researcher is less than in a lab or field experiment
• likelihood of desired behaviour being displayed: naturally occurring situation that researcher wishes to study may only occur rarely

Term "correlation" refers to statistical technique that measures the relationship between 2 variables, i.e the extent of which high values on one variable are associatd with high values on another

Many correlation techniques calculate a "correlation co-efficient" a statistic that has a value on a scale between +1 and -1.

Advantages of correlational analysis:

• measuring the strength of relationships: provide precise quantitative measure of the strength of relationship between variables
• value to exploratory research: correlational techniques allow for measurement of many variables and relationships between them

Disadvantages of correlational analysis:

• issue of causality: not possible to establish cause and effect through research investigations using correlational analysis
• measurement of non linear relationships: cannot be measured by commonly used correlational techniques

Summary:

• Behaviour is observed and recorded and there is usually no deliberate manipulation of variables
• provides an alternative to tightly controlled research methods such as lab experiments
• no attempt is made to influence behaviour being investigated in any way
• method can be used in situations where other form of intervention would be inappropriate or unethical
• observational research can differ in several important ways, depends on:
• setting in which setting is carried out
• role of researcher
• the amount of structure imposed

Advantages:

• value as a preliminary research tool: careful observation can lead to the identification of appropriate hypotheses for further investigation
• Validity: naturalistic observation can provide a useful means of checking whether experimental findings apply outside lab conditions

Disadvantages:

• control: level of control over confounding variables is poor
• replication: can be difficult due to problems that arise when trying to control variables such as differences between naturalistic settings
• observer effects: possible observer may change the behaviour of those being observed, especially when a small group is being studied
• ecological validity and realism: likely to be lower in observational research
• costs:  can be high
• coding systems: may limit on constrain how the data gathered are categorized
• generalizing findings: uniqueness of observational situation may make this difficult

• Can be used in a wide range of research situations
• Allows researcher to ask participants about attitudes, behaviours or intentions
• Can be conducted by post, telephone or via the internet
• qualititative and quantitative data may be produced 
• closed questions: researcher determines the range of possible answers, often by ticking boxes or circling answers
• open ended questions: researcher doesn't restrict range of available answers
• leading questions: choice of wording used suggests that the respondent should reply in a particular way
  
  

How to make a good questionnaire:

• short questions
• minimum number of questions
• word questions carefully
• avoid emotionally sensitive questions

Advantages:

• simplicity: questionnaires can be used with minimum training once developed and piloted
• speed and cost: large amounts of into can be gathered quickly and cheaply within short time frame
• less interpersonal influence: researchers don't sit with respondents when they complete a questionnaire

Disadvantages:

• problem of question wording: ambiguity
• leading questions
• different interpreations of language
• poorly designed questionnaires = poor data
• response rates are low

Summary:

• common way of carrying out research
• 3 types of interview: structured, unstructured, semi-structured
• Structured: aim to produce quantitative data and include pre-determined questions
• pros of structured:
  - less likely to deviate from topic
  - simpler data analysis
  -less training required
• Limitations:
  - cannot follow up any lines of enquiry that emerge
  - validity may be threatened due to formality of research situation
• Unstructured interview: far less rigid and very little will be decidd in advance
• Usually start of 1 or 2 set questions before broadening the focus
• Semi structured: most successful approach
• some questions pre-pared with additional questions giving inteviewee option of expanding 

Advantages:

• Flexibility: interview can enable researcher to explore complex issues that would be harder to do using other techniques
• tackling senitive topics: allows researchers to identify private and personal aspects of behaviour

Disadvantages:

• Interpreting data: can occur easily, had to transform qualititative data into quantitative data
• time and effort required
• limitations in interviewee's responses: may be unable to articulate thoughts clearly
• effects of interpersonal variables e.g gender, ethnicity, personality, class or age
• demand characteristics
• need for training
• costs a lot

Summary:

• usually involve in-depth study over time of a "case"
• usually a single individual or a small group
• research undertaken within a real-life context
• may involve a representative case
• exceptional or unique circumstance may be studied e.g twins separated at birth
• data mainly gathered through interviews and observation
• data is usually qualititative

Advantages:

• rich and interesting data: case studies produce data that has a high degree of realism and can provide valuable new insights into what is being studied
• challenges existing theory: if findings contradict a well established theory, we have to consider modifying the theory in some way to accommodate for the new evidence

Disadvantages:

• low reliability
• findings may be subjuective: case studies usually based on lengthy in-depth interviews, relationship may be formed
• distortions: if an individual is required to recall historical events, data can become distorted due to memory errors