Chapter 2: Research Methods PDF

What is empiricism? What is the scientific method? What is a theory? A hypothesis? What is an operational definition? o Empiricism is a philosophical approach that emphasizes knowledge derived from sensory experience. It posits that knowledge comes primarily from observable...

What is empiricism? What is the scientific method? What is a theory? A hypothesis? What is an operational definition? o Empiricism is a philosophical approach that emphasizes knowledge derived from sensory experience. It posits that knowledge comes primarily from observable evidence and experimentation rather than from innate ideas or traditions. In psychology, empiricism underlines the importance of collecting data through observation and experimentation to draw conclusions about behavior and mental processes. o The scientific method is a systematic process used for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. o A theory is a well-substantiated explanation of some aspect of the natural world that is based on a body of evidence and has stood up to repeated testing and scrutiny. o A hypothesis is a specific, testable prediction about the relationship between two or more variables. o An operational definition specifies how a concept or variable will be measured or manipulated in a particular study. Measurements need to have construct validity, reliability and power – what are each of these? Which refers to whether a measure is consistent (reliability)? Which refers to whether a measure is measuring what it is supposed to measure (validity)? o Construct validity refers to whether a measurement accurately reflects the theoretical construct it is intended to measure. ▪ Reliability refers to the consistency of a measurement. ▪ Power in the context of measurement refers to the ability of a measure to detect an effect or a difference when one exists. What are demand characteristics and how can they be a problem when observing people? What is naturalistic observation? What is a double blind observation and why might it be needed? o Demand characteristics refer to cues or signals in a research study that may influence participants to behave in a certain way or to respond in a manner they believe aligns with the study's expectations. ▪ They can lead to biased results; They may compromise the internal validity of the study. o Naturalistic observation is a research method where behavior is observed in its natural environment without any manipulation or control by the researcher. o A double-blind observation is a research method where both the participants and the experimenters do not know which participants are receiving a particular treatment or intervention and which are in the control group. This approach helps to mitigate biases in the study. What is a variable? What is a correlation? With a correlation, why can we not say that one variable causes the other? See Figure 2.2. What is the third-variable problem?  Also review the section on Measuring Correlation on page A-4 and A-5 in the Appendix. You should understand what a positive correlation and a negative correlation are. For instance, if as height increases, weight also tends to increase, is this a positive or negative correlation? o A variable is any characteristic, trait, or phenomenon that can change or vary within the context of a study or experiment. o A correlation is a statistical measure that describes the extent to which two variables are related to each other. ▪ Positive Correlation: Indicates that as one variable increases, the other variable also tends to increase (and vice versa). ▪ Negative Correlation: Indicates that as one variable increases, the other variable tends to decrease o With a correlation, we cannot say that one variable causes the other for several reasons: ▪ Third-Variable Problem: This refers to the possibility that a third, unmeasured variable could be influencing both correlated variables. ▪ Directionality Problem: Even if two variables are correlated, it is unclear which variable influences the other. While a correlation only measures variables, an experiment manipulates one variable. What is an experiment? What is manipulation? What is random assignment? What is an independent variable? What is a dependent variable? What is an experimental group? What is a control group? Given examples of studies, you should be able to identify the independent variable, the dependent variable, the experimental group and the control group. o An experiment is a research method used to determine causal relationships between variables. o Manipulation refers to the process of intentionally changing or controlling one or more variables in an experiment to observe the effects of that change. o Random assignment is a technique used in experiments to ensure that participants are placed into different groups (such as the experimental and control groups) in a random manner. This process helps to eliminate bias and ensures that the groups are comparable at the start of the experiment. o An independent variable is the variable that is manipulated by the researcher in an experiment. o A dependent variable is the variable that is measured or observed in an experiment. o The experimental group is the group in an experiment that receives the treatment or manipulation being tested. o The control group is the group in an experiment that does not receive the experimental treatment or manipulation.  What is self-selection and why is it a problem in experiments? What is random assignment and how does it help with the self-selection problem? o Self-selection occurs when individuals determine their own participation in a study, leading to non-random assignment to different groups within an experiment. o Self-selection is problematic because it can lead to selection bias, which occurs when the groups being compared are not equivalent at the outset of the experiment. o Random assignment is a method used in experiments to assign participants to different groups (such as experimental and control groups) in a random manner. What does it mean to say that the difference between the control group and experimental group are statistically significant? o Saying that the difference between the control group and experimental group is statistically significant means that the observed difference in outcomes (such as means, proportions, or other statistical measures) between the two groups is unlikely to have occurred by random chance alone. In other words, the results are deemed meaningful and suggest that the independent variable (the treatment or intervention) had a real effect. What is internal validity? What is external validity? Which type of validity refers to our ability to draw inferences about cause and effect? Which allows us to generalize to the “real” world? o Definition: Internal validity refers to the degree to which an experiment accurately establishes a cause-and-effect relationship between the independent variable (the manipulated variable) and the dependent variable (the measured outcome). o Definition: External validity refers to the extent to which the findings of a study can be generalized to, or have relevance for, settings, people, times, and measures beyond the specific context of the research. o External validity allows us to generalize findings to the "real" world. What is the case method? What is a population? What is a sample? What is random sampling? o Definition: The case method is a research approach that involves an in-depth investigation of a single individual, group, event, or phenomenon. o Definition: In research, a population refers to the entire group of individuals or instances that meet a specific set of criteria for a particular study. o Definition: A sample is a subset of the population selected for participation in a study. Researchers use samples to draw conclusions about the population without having to survey every individual within that group. o Definition: Random sampling is a technique used to select a sample from a population in such a way that every individual has an equal chance of being chosen.  You should be familiar with the ethical guidelines for research with human participants including informed consent, debriefing, and the risk-benefit analysis.