Research Methods: Variables and Study Design

• Psychologists study the behavior of humans and animals to understand people and improve human lives.
• Psychological research results are relevant to learning, memory, homelessness, psychological disorders, family instability, aggressive behavior, and violence.

Basic vs. Applied Research

• Basic research answers fundamental questions about behavior.
• Applied research investigates issues with implications for everyday life and provides solutions to everyday problems.
• Psychological research results are reported in scientific articles in journals.
• Research in scientific journals goes through evaluation, critique, and improvement by scientists via peer review.

Scientific Method

• Psychologists use the scientific method to guide their research.
• Psychologists use research as the best tool for understanding humans and their relationships.
• Statements made by psychologists are empirical, based on systematic data collection and analysis.
• The scientific method includes assumptions, rules, and procedures for conducting research.
• Science should be empirical, and the scientific method demands objective procedures without personal bias or emotions.

Laws and Theories

• Research aims to organize information into meaningful statements applicable in many situations.
• General principles applying to all situations in a domain of inquiry are known as laws.
• Theory is the next step down from laws in the hierarchy of organizing principles.
• A theory is an integrated set of principles that explains and predicts many observed relationships within a given domain of inquiry.
• Good theories are general, summarizing many outcomes.
• Good theories are parsimonious, providing the simplest account of those outcomes.
• Good theories are generative, providing ideas for future research.
• Good theories are falsifiable, meaning variables of interest can be adequately measured.

Research Hypothesis

• A research hypothesis is a specific and falsifiable prediction about the relationship between two or more variables.
• A variable is any attribute that can assume different values among different people or across different times or places.
• An example research hypothesis: "Using marijuana will reduce learning."
• Operational definition refers to a precise

Ethical Research

• All scientists must address the ethics of their research.
• Psychology research may cause stress, harm, or inconvenience to participants.
• Psychologists may induce stress, anxiety, or negative moods, expose participants to weak electrical shocks, or convince them to behave against their moral standards.
• Decisions about research ethics use established codes from scientific organizations.

Ethical Research Characteristics Using Human Participants

• Consideration of important factors by psychologists when designing research
• Trust and positive rapport between researcher and participant
• Experimenter and participant rights are considered and mutually beneficial.
• The experimenter treats participants with concern and respect, making the research experience pleasant and informative.
• Participants can ask questions and have procedures explained, guaranteeing their choice to participate.

American Psychological Association Code of Ethics

• No harm is a direct ethical concern of the researcher that prevents harm to participants.
• Informed consent is conducted before a participant begins a research session to explain procedures and inform participants of their rights.
• Confidentiality is when researchers protect the privacy of research participants.
• Deception occurs when research participants are not completely informed about the nature of the research project before participating.
• Debriefing is a procedure to fully explain the purposes and procedures of the research.

Types of Research

• Researchers use descriptive, correlational, and experimental research designs to understand behavior.
• Psychologists agree that ideas and theories about behavior must be supported by data.
• Research designs are the specific methods researchers use to collect, analyze, and interpret data.
• Descriptive research observes specific behaviors and records the observation.
• Correlational research discovers relationships among variables and allows prediction of future events.
• Experimental research creates initial equivalence among participants in multiple groups.
• Groups are created and followed by manipulation of a given experience for the groups that are measured for its influence.

Descriptive Research

• Descriptive research is designed to create a snapshot of current thoughts, feelings, or behaviors of individuals.
• Case studies form one type of descriptive research.
• Case studies are based on data from a small set of individuals and are descriptive records of one or more individual's experiences and behavior.
• Surveys are data in descriptive research projects formed as questions administered via interviews or written questionnaires to picture beliefs or behaviors of a sample of people of interest.
• A final type of descriptive research is known as observation.
• Naturalistic observation is used by

Correlation Research

• Correlational research contrasts with descriptive research, which is designed to provide static pictures.
• Correlational research involves measuring multiple relevant variables and assessing the relationship among those variables.
• Variables that change in the same direction are said to have a positive correlation
• A negative correlation occurs when values for one variable change in the opposite direction for another variable

Experimental Research

• Experimental research provides definitive conclusions about causal relationships among the variables in the research hypothesis.
• The variables of interest in the experimental research design are called the independent variable and the dependent variable.
• The independent variable is the causal variable that is created or manipulated by the experimenter.
• The dependent variable is a measured variable that is expected to be influenced by the experimental manipulation.
• A good experiment has at least two groups that are compared.
• The experimental group receives the experimenters' manipulation like medication for depression.
• The comparison group(control group) gets no manipulation or nothing out of the ordinary to make this a fair comparison.

Experimental Research Advantages and Disadvantages

• Experimental designs have features that they guarantee the independent variable occurs before the dependent variable measurement to eliminate reverse causation.
• The influence of third variables is controlled and eliminated.
• Despite the advantage of determining causation, experiments are limited.
• Experiments are often conducted in laboratory situations rather than in everyday lives.
• Key social variables cannot be

Credible Research Factors

• Validity means that good research conclusions drawn by the researcher are legitimate.
• Valid research works like psychotherapy reducing anxiety.
• Reliability means that One threat to valid research is that the measured variables are not reliable or consistent.
• Statistical significance refers to the confidence with which a scientist can conclude that data are not due to chance or random error.
• Experimenter bias is a threat to validity, leading to researchers subtly treating research

Avoiding Bias and Replication

• Double-Blind Experiments: Experiments are frequently run where both the researcher's and the patient's are unaware of the conditions to avoid experimenter bias.
• This means experimeters lack the knowledge conditions that participants are assigned too, and experimenter conditions do not occur.
• Replication: Repeating previous research which forms the basis of all scientific inquiry.

Test your knowledge of research methods with these questions. Topics covered include correlation, independent vs. dependent variables, control groups, and experimental validity. Perfect for students studying research design.