Summary and Key Terms
- archival research
- method of research using past records or data sets to answer various research questions, or to search for interesting patterns or relationships
- attrition
- reduction in number of research participants as some drop out of the study over time
- cause-and-effect relationship
- changes in one variable cause the changes in the other variable; can be determined only through an experimental research design
- clinical or case study
- observational research study focusing on one or a few people
- confirmation bias
- tendency to ignore evidence that disproves ideas or beliefs
- confounding variable
- unanticipated outside factor that affects both variables of interest, often giving the false impression that changes in one variable causes changes in the other variable, when, in actuality, the outside factor causes changes in both variables
- control group
- serves as a basis for comparison and controls for chance factors that might influence the results of the study—by holding such factors constant across groups so that the experimental manipulation is the only difference between groups
- correlation
- relationship between two or more variables; when two variables are correlated, one variable changes as the other does
- correlation coefficient
- number from -1 to +1, indicating the strength and direction of the relationship between variables, and usually represented by r
- cross-sectional research
- compares multiple segments of a population at a single time
- debriefing
- when an experiment involved deception, participants are told complete and truthful information about the experiment at its conclusion
- deception
- purposely misleading experiment participants in order to maintain the integrity of the experiment
- deductive reasoning
- results are predicted based on a general premise
- dependent variable
- variable that the researcher measures to see how much effect the independent variable had
- double-blind study
- experiment in which both the researchers and the participants are blind to group assignments
- empirical
- grounded in objective, tangible evidence that can be observed time and time again, regardless of who is observing
- experimental group
- group designed to answer the research question; experimental manipulation is the only difference between the experimental and control groups, so any differences between the two are due to experimental manipulation rather than chance
- experimenter bias
- researcher expectations skew the results of the study
- fact
- objective and verifiable observation, established using evidence collected through empirical research
- falsifiable
- able to be disproven by experimental results
- generalize
- inferring that the results for a sample apply to the larger population
- hypothesis
- (plural: hypotheses) tentative and testable statement about the relationship between two or more variables
- illusory correlation
- seeing relationships between two things when in reality no such relationship exists
- independent variable
- variable that is influenced or controlled by the experimenter; in a sound experimental study, the independent variable is the only important difference between the experimental and control group
- inductive reasoning
- conclusions are drawn from observations
- informed consent
- process of informing a research participant about what to expect during an experiment, any risks involved, and the implications of the research, and then obtaining the person’s consent to participate
- Institutional Animal Care and Use Committee (IACUC)
- committee of administrators, scientists, veterinarians, and community members that reviews proposals for research involving non-human animals
- Institutional Review Board (IRB)
- committee of administrators, scientists, and community members that reviews proposals for research involving human participants
- inter-rater reliability
- measure of agreement among observers on how they record and classify a particular event
- longitudinal research
- studies in which the same group of individuals is surveyed or measured repeatedly over an extended period of time
- naturalistic observation
- observation of behaviour in its natural setting
- negative correlation
- two variables change in different directions, with one becoming larger as the other becomes smaller; a negative correlation is not the same thing as no correlation
- observer bias
- when observations may be skewed to align with observer expectations
- operational definition
- description of what actions and operations will be used to measure the dependent variables and manipulate the independent variables
- opinion
- personal judgments, conclusions, or attitudes that may or may not be accurate
- participants
- subjects of psychological research
- peer-reviewed journal article
- article read by several other scientists (usually anonymously) with expertise in the subject matter, who provide feedback regarding the quality of the manuscript before it is accepted for publication
- placebo effect
- people’s expectations or beliefs influencing or determining their experience in a given situation
- population
- overall group of individuals that the researchers are interested in
- positive correlation
- two variables change in the same direction, both becoming either larger or smaller
- random assignment
- method of experimental group assignment in which all participants have an equal chance of being assigned to either group
- random sample
- subset of a larger population in which every member of the population has an equal chance of being selected
- reliability
- consistency and reproducibility of a given result
- replicate
- repeating an experiment using different samples to determine the research’s reliability
- sample
- subset of individuals selected from the larger population
- single-blind study
- experiment in which the researcher knows which participants are in the experimental group and which are in the control group
- statistical analysis
- determines how likely any difference between experimental groups is due to chance
- survey
- list of questions to be answered by research participants—given as paper-and-pencil questionnaires, administered electronically, or conducted verbally—allowing researchers to collect data from a large number of people
- theory
- well-developed set of ideas that propose an explanation for observed phenomena
- validity
- accuracy of a given result in measuring what it is designed to measure
Why Is Research Important?
Scientists are engaged in explaining and understanding how the world around them works, and they are able to do so by coming up with theories that generate hypotheses that are testable and falsifiable. Theories that stand up to their tests are retained and refined, while those that do not are discarded or modified. In this way, research enables scientists to separate fact from simple opinion. Having good information generated from research aids in making wise decisions both in public policy and in our personal lives.
Research Methods
The clinical or case study involves studying just a few individuals for an extended period of time. While this approach provides an incredible depth of information, the ability to generalize these observations to the larger population is problematic. Naturalistic observation involves observing behaviour in a natural setting and allows for the collection of valid, true-to-life information from realistic situations. However, naturalistic observation does not allow for much control and often requires quite a bit of time and money to perform. Researchers strive to ensure that their tools for collecting data are both reliable (consistent and replicable) and valid (accurate).
Surveys can be administered in a number of ways and make it possible to collect large amounts of data quickly. However, the depth of information that can be collected through surveys is somewhat limited compared to a clinical or case study.
Archival research involves studying existing data sets to answer research questions.
Longitudinal research has been incredibly helpful to researchers who need to collect data on how people change over time. Cross-sectional research compares multiple segments of a population at a single time.
Correlation vs. Causation
A correlation is described with a correlation coefficient, r, which ranges from -1 to 1. The correlation coefficient tells us about the nature (positive or negative) and the strength of the relationship between two or more variables. Correlations do not tell us anything about causation—regardless of how strong the relationship is between variables. In fact, the only way to demonstrate causation is by conducting an experiment. People often make the mistake of claiming that correlations exist when they really do not.
Researchers can test cause-and-effect hypotheses by conducting experiments. Ideally, experimental participants are randomly selected from the population of interest. Then, the participants are randomly assigned to their respective groups. Sometimes, the researcher and the participants are blind to group membership to prevent their expectations from influencing the results.
In ideal experimental design, the only difference between the experimental and control groups is whether participants are exposed to the experimental manipulation. Each group goes through all phases of the experiment, but each group will experience a different level of the independent variable: the experimental group is exposed to the experimental manipulation, and the control group is not exposed to the experimental manipulation. The researcher then measures the changes that are produced in the dependent variable in each group. Once data is collected from both groups, it is analyzed statistically to determine if there are meaningful differences between the groups.
Psychologists report their research findings in peer-reviewed journal articles. Research published in this format is checked by several other psychologists who serve as a filter separating ideas that are supported by evidence from ideas that are not. Replication has an important role in ensuring the legitimacy of published research. In the long run, only those findings that are capable of being replicated consistently will achieve consensus in the scientific community.
Ethical Considerations
Ethics in research is an evolving field, and some practices that were accepted or tolerated in the past would be considered unethical today. Researchers are expected to adhere to basic ethical guidelines when conducting experiments that involve human participants. Any experiment involving human participants must be approved by an IRB. Participation in experiments is voluntary and requires informed consent of the participants. If any deception is involved in the experiment, each participant must be fully debriefed upon the conclusion of the study.
Animal research is also held to a high ethical standard. Researchers who use animals as experimental subjects must design their projects so that pain and distress are minimized. Animal research requires the approval of an IACUC, and all animal facilities are subject to regular inspections to ensure that animals are being treated humanely.
Key Terms:
