Psychology's Scientific Method: Comprehensive Notes

Duchenne Smiling and Genuine Happiness

• Researchers have identified Duchenne smiling (with wrinkles around the eyes) as a sign of genuine happiness.

Operational Definitions

• Operational definitions allow for the measurement of variables like generosity, love, maturity, exhaustion, and physical attractiveness.

• Operational definitions are crucial for conducting research because they enable researchers to quantify abstract concepts.

Data Analysis

• Data analysis involves mathematically "crunching" numbers collected in a study to determine whether they support the predictions.

Self-Determination Theory Example

• Self-determination theory posits that people feel fulfilled when they meet three needs: relatedness, autonomy, and competence.

• Hypothesis: People who value extrinsic rewards (money, material possessions) over intrinsic rewards (relatedness, autonomy, competence) are less fulfilled.

• Kasser and Ryan's Studies: "The Dark Side of the American Dream."

• Operational definitions: Values and psychological functioning were measured using questionnaire scores.

• Findings: Individuals who value material rewards over intrinsic rewards tend to suffer as predicted.

Steps in the Scientific Method

1.  Drawing Conclusions:

• Based on data analysis, scientists draw conclusions about whether the data supports predictions.

• Researchers write articles presenting their findings, which undergo peer review in scientific journals.

  2. Evaluating the Theory:

• The scientific community evaluates published papers in light of other research.

• Theories are revised after multiple studies produce similar results.

Replication

• Replication: Repeating a study and obtaining the same results.

• Direct replication: Conducting the study precisely as it was originally done.

• Conceptual replication: Conducting the study with different methods or samples.

• Reliable results: Findings that are consistently replicated across different researchers and methods.

Replication Crisis

• Replication Crisis: Many fields of science, including psychology, have faced issues where results from studies could not be reproduced by other investigators.

• Principles to guide researchers:

  • Use large numbers of participants.

  • Pool data across labs.

  • Transparency and thoroughness in reporting methods.

  • Provide public access to original data.

  • Preregister hypotheses, predictions, and methods.

Meta-Analysis

• Meta-analysis: A statistical procedure that summarizes a large body of evidence from the research literature on a particular topic.

• Process: A researcher tries to find all studies done on a topic of interest and compares the results from those studies.

• Benefits:

  • Determines whether a result is consistent across many studies.

  • Estimates the size of the relationship between variables.

  • Identifies factors that influence the results.

• Meta-analytic results are more powerful than those of a single study.

• Example: Meta-analysis of the relationship between kindness and happiness, the analysis combined 201 different studies involving nearly 200,000 people in all. The results showed that those who behave kindly do show a small boost in happiness.

Ongoing Evaluation and Revision

• The research community maintains an active conversation and constantly questions conclusions.

• Published papers provide a snapshot of current knowledge, but conclusions are always open to revision.

Types of Psychological Research

• Descriptive research: Determines the basic dimensions of a phenomenon.

• Correlational research: Seeks to discover relationships among variables.

• Experimental research: Concerns establishing causal relationships between variables.

Descriptive Research

• Descriptive research describes a phenomenon-determining its basic dimensions and defining what it is, how often it occurs, and so on.

• It can help identify problems, but cannot prove what causes some phenomenon.

• Descriptive research methods include: observation, interviews and surveys, and case studies.

Observation

• Scientific observation requires important skills like knowing what to look for, remembering what was seen, and documenting accurately.

• Systematic observation involves knowing whom, when, and where to observe, and how to document observations.

• Observations must be systematic.

Interviews and Surveys

• Interviews and surveys are used to gather information about people's experiences, attitudes, and beliefs.

Correlational Research

• Correlational research seeks to discover relationships among variables.

• Correlation coefficient (r) is used to express the degree of relationship between two variables.

  • Ranges from -1.00 to +1.00.

  • The sign indicates the direction of the relationship (positive or negative).

  • The absolute value indicates the strength of the relationship.

• Positive correlation: Variables vary in the same direction.

• Negative correlation: Variables vary in opposite directions.

• Zero correlation: No systematic relationship between variables.

Third Variable Problem

• Third Variable Problem: An extraneous factor that may account for the relationship between two other variables.

• Variables are also known as confounds.

• Example: Ice cream sales and violent crimes are positively correlated; heat is the third variable.

Cross-Sectional Design

• Cross-sectional design: A type of correlational study in which variables are measured at a single time point.

Value of Correlational Research

• Correlational studies allow us to use one variable to predict a person's score on another.

• Some questions can only be investigated through correlational studies, such as those involving age, gender identity, personality traits, genetic factors, and ethnic background.

• Correlational research is also valuable in cases where it would not be ethical to do the research in any other way.

• Researchers often include many variables in their studies. In this way, they can assess whether a connection between two variables is explained by a third (or fourth or fifth) variable.

Ecological Momentary Assessment (EMA)

• Correlational researchers often use reports that track experiences, known as ecological momentary assessment (EMA), to assess people in their natural settings.

• Participants often use their smartphones and download an app to participate in EMA studies.

Longitudinal Designs

• Longitudinal design: A special kind of systematic observation that involves obtaining measures of the variables of interest in multiple waves over time.

• Longitudinal research can suggest potential causal relationships because if one variable is thought to cause changes in another, it should at least come before that variable in time.

• The Nun Study: A longitudinal study that has followed a sample of 678 School Sisters of Notre Dame since 1986.