Introduction to Research Methods in Psychology L.A. Siegel, MA, CSE, AASECT

Three Types of Research Causal Research determines if one variable causes another variable to occur or change. 2. Descriptive Research seeks to depict what already exists in a group or population (eg, opinion poll, market survey) 3. Relational Research investigates the connection between two or more variables generally already present in the group or population (eg, gender and music preference)

Some important distinctions between theory and hypothesis A theory is has been extensively tested and is based on generally accepted facts. A theory is a well-established principle that has been developed to explain some aspect of the natural world. A theory arises from repeated observation and testing and incorporates facts, laws, predictions, and tested hypotheses that are widely accepted. A hypothesis is a speculative guess that has yet to be tested

Effect of Time in Psychology Research Cross-sectional research (single point in time) Seeks to gather data on present conditions instead of looking at the effects of a variable over a period of time. 2. Longitudinal research (over a period of time) Data is first collected at the outset of the study, and may then be gathered repeatedly throughout the length of the study. Some longitudinal studies may occur over a short period of time, such as a few days, while others may take place over a period of decades.

Causal Relationships Between Variables A causal relationship is when one variable causes a change in another variable. These types of relationships are investigated by experimental research in order to determine if changes in one variable truly causes changes in another variable

Correlational Relationships Between Variables A correlation is the measurement of the relationship between two variables that already occur in the group or population; not controlled by the experimenter. positive correlation negative correlation

What is a Simple Experiment? is used to establish cause and effect; often used to determine the effect of a treatment. study participants are randomly assigned to one of two groups. control group: receives no treatment experimental group: receives treatment.

Parts of a Simple Experiment The experimental hypothesis: a statement that predicts that the treatment will cause an effect. The null hypothesis: a hypothesis that the experimental treatment will have no effect on the participants or dependent variables.

Parts of a Simple Experiment The independent variable: the treatment variable manipulated by the experimenter. The dependent variable: the response that the experimenter is measuring.

Determining the Results of a Simple Experiment The key to determining if a treatment had an effect is to measure the statistical significance. Statistical significance shows that the relationship between the variables is probably not due to mere chance and that a real relationship most likely exists between the two variables. Statistical significance is often represented as: p < .05 or .01

What is Validity? Validity is the extent to which a test measures what it claims to measure. It is vital for a test to be valid in order for the results to be accurately applied and interpreted.

What Is Reliability? Reliability refers to the consistency of a measure. A test is considered reliable if we get the same result repeatedly. .

Types of Research Design Case Series and Case Reports: Collections of reports on the treatment of individual patients with the same condition, or of several reports on a single patient Case Control Studies: Patients who already have a certain condition are compared with people who do not.

Randomized Controlled Studies: Cohort Studies: longitudinal studies involve a case-defined population who presently have a certain exposure and/or receive a particular treatment that are followed over time. Randomized Controlled Studies: treatment group and control group are randomly assigned. The treatment group receives the treatment under investigation, and the control group receives either no treatment (placebo) or standard treatment. Considered the “Gold” Standard in Medical Research

Double Blind Method: Single-Blind Method: randomized controlled clinical study in which neither the research staff nor the subject knows which of several possible treatments/therapies the patient is receiving. Single-Blind Method:  researchers know which group is receiving which treatment. Allows for bias on the part of the researchers conducting the study.

Clinical Development: The Fundamentals Phase of study Aim Subject population Number of subjects Approximate duration (years) Phase I Pharmacokinetics & Safety Healthy volunteers 50–100 1 Phase II Proof of concept Dose–response Patients 100–300 2 Phase III Efficacy Target patient population 1,000–5,000 3 Phase IV Post approval Variable

Phase I – Data Collected Bioavailability Peak serum concentration (Cmax) Time to maximum concentration (Tmax) Area under the curve Tolerability and safety Effects on vital signs Half-life (T½) Pharmacokinetics Pharmacodynamics Protein binding Dosage form Food effect Drug–drug interactions

Phase II – Data Required Safety profile in patients Proof of concept Dose range Frequency of dosing Safety/tolerability

Phase III – Formal Trials Two identical trials to demonstrate: Multi-center, multi-national trials Long-term safety Controlled, blinded, and randomized

Phase IV – Commitments Post approval, therapeutic use Additional safety data Long-term/chronic use Differentiate from other drugs in class Cost-effectiveness

FDA Review Process Takes approximately one year for the FDA to review a New Drug Application (NDA). Review is done by the Division of Reproductive and Urological Products Often hold an Advisory Board Meeting to review data from clinical trials and to offer recommendations regarding approval In general, FDA follows the recommendations of the Advisory Board Three possibilities Approval Letter of Approvability Letter of Non-approval

Contributions to the Approval Process Regulatory Environment & Societal Influences Efficacy Safety

In What Ways Do We Live Our Lives According to the Scientific Method?