Psychology Research Methods Notes PDF

# Subject: Psychology 12 Half Term: Experiment Designs ## 1. Hypotheses and Variables * **Aim**: Statement of the research purpose. * **Hypothesis**: A testable statement about the relationship between two variables. In an experiment these variables are called independent variable (IV) and the dep...

# Subject: Psychology 12 Half Term: Experiment Designs ## 1. Hypotheses and Variables * **Aim**: Statement of the research purpose. * **Hypothesis**: A testable statement about the relationship between two variables. In an experiment these variables are called independent variable (IV) and the dependent variable (DV). * **Null hypothesis**: A statement predicting no relationship between two variables. * **Directional hypothesis**: Predicts the direction (outcome) of the results. * **Non-directional hypothesis**: Predicts that there will be a difference, but does not predict the direction. * **Independent variable (IV)**: The variable that the researcher alters or manipulates to look for the effect on another variable. This variable produces the two conditions of the study. * **Dependent variable (DV)**: The variable that the ## 2. Experimental Methods * **Laboratory Experiments**: Experiment is high in control over what happens. * EV's can be controlled so cause and effect can be established. Also uses standardized procedures = high reliability. * Difficult to generalise behaviour from a lab = less normal = demand characteristics. * **Field Experiments**: Take place in a natural setting, IV manipulated by the experimenter. * More realistic behaviour = higher in ecological validity. * May lose control of EV's so difficult to establish cause and effect = low validity. Also ethical issues such as consent, deception more likely. * **Natural Experiments**: Take place in a field or a lab. IV is not changed by the researcher, it happens naturally. * Higher validity = real world. * EV's are less controlled = affects results. ## 3. Types of Experimental Designs * **Independent Groups**: Different groups of participants for each condition. * No Order Effects * Individual differences of pp's = lowers validity of results. * **Repeated Measures**: All participants take part in both conditions. * No participant variables (i.e. individual differences) * Issue of order effects. * **Matched Pairs**: Pp's are tested on variables relevant to the study (e.g. age, gender etc.) and then matched and one person from each pair completes one condition. ## 4. Ethical Issues * BPS guidelines are a code of conduct all professional psychologists should follow. * **Informed Consent**: Participants should be told of the purpose of the research and that they can leave at any time. * **Deception**: Participants should not be lied to or misled about aims. * **Privacy**: Participants have the right to control information about themselves. * **Confidentiality**: Personal data must be protected and respected. * **Dealing with ethical issues**: * **Informed consent**: Sign a form telling them what is expected. * **Deception**: Full debrief to explain true aims. * **Protection from harm**: Debrief and follow up (counselling) * **Privacy and confidentiality**: Keep details anonymous (numbers instead of names). ## 5. Sampling and Sampling * **Target population**: Large group of people the research wished to study * **Sample**: Small group of people representing Target population. * **Representative**: Sample made up of people with the same characteristics and abilities of target population. * **Generalised**: Results can be applied to target population. * **Random**: Each person has an equal chance of being selected. No bias - time consuming. * **Opportunity**: Selecting people available at time. * **Systemic**: Every Nth person from a list selected. Avoids researcher bias - unrepresentative sample. * **Stratified**: Selecting pp's from sub ## 6. Observational Techniques and * **Participant observations**: Observers become actively involved in the situation being studied. * **Non participant observation**: Observers do not become actively involved in the situation being studied. * **Overt**: Pp's aware of aims and being observed. * **Covert**: Pp's remain unaware of being observed. * **High external validity**: Real-world application. * **Observer bias**: Reduces validity. * **Behavioural categories**: Dividing target behaviours into subsets of behaviours through use of coding systems. * **Event sampling**: Counting the number of times a behaviour occurs in a target individual. * **Time sampling**: Counting behaviour in a set. ## 7. Self-Report Techniques * Participants giving information about themselves without researcher interference. * **Questionnaires**: Pp's record their own answers to a pre-set list of questions. * **Types of questions**: * **Closed questions**: Require a yes/no response or a multiple choice. * **Open questions**: Pp's answer in their own words. Quick and large amount of detail. Low response rate. * **Interviews**: Pp's answer questions in face to face situations. * **Structured**: Identical closed questions asked by researcher. * **Unstructured**: Informal discussion on particular topic. ## 8. Correlational Studies * Look for a relationship between two variables. * Allows predictions to be made. ## 9. Pilot Studies and Peer Reviews * **Pilot study**: A trial run of an experiment done before the real experiment to check for any issues within the research, to change in time for the actual study. * Ensures validity of results. * Time consuming. * **Peer review**: Scrutiny by experts of research papers to determine scientific validity ## 10. Data handling and Descriptive * **Quantitative**: Data in a numerical form. * **Qualitative**: Non-numerical data, i.e. meanings, feelings, expressions, words. * **Primary data**: Collected specifically towards a research aim, which has not been published before. * **Secondary data**: Originally collected towards another research aim and has been published before. * **Meta-analysis**: A process which a large number of studies, have involved the same research questions and methods are reviewed together and compared to see if there are similarities in the research. * **Measures of central tendancy**: Methods of estimating mid-point scores in sets of data (e.g. mode, median, mean). * **Measures of dispersion**: Measurements of the range, within ## 11. Graphs and Distributions * **Bar charts**: Show data in the form of categories. * **Histograms**: Similar to bar charts but used for continuous data (i.e. test scores) no spaces between bars. * **Normal distribution**: Data with an even distribution of scores either side of the mean. * **Skewed distribution**: Data that does not have an even distribution of scores either side of the mean. ## 12. Sign Test * A non-parametric statistical test used for experiments where data is at least nominal and a repeated measures design has been used.