Lecture 2 notes Lecture 2: Research methods in Psychology 1. Psychology: Scientific approach to behavior 2. Research methods in Psychology: Experimental and non-experimental approaches 3. Ethical issues in psychological research 1) Psychology: Scientific approach to behavior Whether the objects of study are gravitational forces or human behaviors under stress, scientific approach assume that events are governed by some lawful orders. Psychologists assume behaviors were governed by discernible laws or principles. The tasks of psychologists are to uncover and verify these laws and principles of behaviors like what Newton has done in physics. 1.1) Goals of scientific studies Three interrelated goals: a) Measure and describe: The first goal of psychology is to development measurement techniques/methods to enable researcher to describe target behaviors clearly, precisely and objectively. Before we can try to explain or predict any behaviors, we have to be able to define and describe it objectively. b) Understand and predict: A higher-level goal of psychology is understanding and predicting. We try to understand certain behaviors (e.g. communicative behaviors) by explaining the reasons for its occurrence (e.g. needs to be understood). In the process of understanding human behaviors, psychologist propose different hypothesis (a tentative and testable statement about the relationship between two or more variables. Variables are any measurable conditions, events, characteristics, or behaviors that are controlled or observed in a study) to test and evaluate their thoughts about patterns of human behavior (e.g. men are less sociable than women or men tends to share emotional events with women). After certain hypothesis were tested, psychologists may propose a theory (“is a system of interrelated ideas used to explain a ser of observations.” p.38) to predict behaviors. refer to Figure 2.1 Theory construction c) Apply and control Once researchers understand a psychological phenomenon, they try to apply the research findings to practical problems in different settings (e.g. training, school or business). Their aims to apply the psychological knowledge they have are in general to promote well-being of human and effectiveness of their behaviors. 1 Q: Can you make up a hypothesis? 1.2) Steps in a scientific study The Five Steps of the Scientific Method 1. Formulating hypothesis Hypothesis – A testable statement which describes the relationship between two variables. It predicts a research outcome that could be either verified or falsified. A research outcome which is consistent with the prediction supports the hypothesis. 2. Designing a research Measurement – Designing valid & reliable ways of measuring variables under study Manipulation and control – Manipulate variables under study & control the effects of unrelated variables Data collection procedures – Design procedures that minimize biases & errors 3. Gathering data Data – Information gathered by researcher in order to test hypothesis Types of data – Can be quantitative or qualitative refer to Table 2.1 Key Data collection techniques in Psychology 4. Analyzing the results 5. Publishing, criticizing, and replicating the results Statistical analyses – to describe numerical data in an interpretable way and to deal with sampling error Qualitative analysis – to organize and categorize data Research findings need to be replicated to be regarded as sufficiently verified Failure to replicate research findings may suggest methodological flaw refer to Figure 2.2 Flowchart of steps in a scientific investigation 1.3) Advantages of scientific approach Findings are clear and precise Findings are more reliable; can be verified and replicable Any limitations of scientific approach? 2 2) Research methods: Experimental and non-experimental approaches Population and sample • Population: Entire set of individuals to which generalizations will be made based on an experimental sample • Sample: Subset of a population selected as participants in an experiment Variables • Independent variable: Variables that are free to vary independently of any other variable in the situation • Dependent variable: Variables that are the result of changes in one or more independent variables • Confounding variable: Variables that are not under concern of the study Types of Psychological Research • Experimental approach: Experiments • Non-experimental/Descriptive approach: Correlational studies; Survey; Naturalistic observations; Case studies Experiments • Contains an experimental group and a control group • The experimental group is treated in the same way as the control group except the systematic manipulation of the independent variables, whereas the dependent variables are compared between groups • Confounding variables are held constant for all conditions Correlational Study • Correlational analysis – Determine to what extent two variables, traits, or attributes are related • Correlational coefficient (r) – Indicates the degree of relationship between two variables • No casual relationship can be tested Survey • A type of correlational study • Usually involve a population-wide sample intending to examine public opinion • Usually descriptive 3 Naturalistic observation • A passive descriptive study in which the presence of observer does not change or alter the behaviors under study • Participant observation - an observational study in which the researcher is actively involved in the situation • More likely for observer bias to occur Case study • Intensive observation of a particular individual or small group of individuals • Examination of the person can be very detailed • However, the results may not be generalized to other individuals What are the pros and cons of each type of studies? Biases and Errors In a scientific study, data often contain errors which may include: • Sampling error • Placebo effects • Experimenter bias---double-blind • Distortions in self-report data: –Social desirability bias –Response set • Confounding variables Controlling biases and errors • Standardization – Set of uniform procedures for treating each participant • Randomization – Participants are randomly assigned to different groups • Double-blind control – Both the observer and the participation have no knowledge to experimental manipulation 4 3) Ethical issues in Psychological research • Informed consent Participants should be given full information about the study before they decide to Participate. Participation should be voluntary and withdrawal during the study is permitted. • Minimal risk The potential of possible harm to the participants has to be minimized. • Deception & debriefing If participants are deceived of anything in the study, they must be debriefed afterwards. • Confidentiality All information obtained in the study are highly confidential and is restricted to use for research purposes. • Research with animals Should animals be used in psychological research? 5
