Research Methods
RESEARCH METHODS
Overview of Research Methods
Research methods are systematic approaches to collect data, analyze findings, and derive conclusions to explore psychological and behavioral phenomena.
Group Level Research Methods
Most Common Type of Research:
Group-level research is the frequently utilized method in scientific studies. It allows for drawing conclusions and evaluating different treatments across various conditions.
Controlled Group Designs
Definition:
Experiments in which groups of participants are exposed to different conditions, including at least one experimental group and one control group.
Key Components:
Independent Variable (IV): Variable that is manipulated or controlled by the experimenter.
Dependent Variable (DV): Variable that is measured to determine the effect of the IV.
Methodologies:
Random Assignment: Ensures that participants have an equal chance of being assigned to any group, promoting internal validity. ( helps de likelihood internal validty of the treatments )
Internal Validity: The extent to which a study accurately measures the relationship between the independent and dependent variables.
External Validity: The generalizability of the research findings to real-world settings. ( expand to more ppl , how much )
efficacy; you have to show how your tretamnets works
effectiveness ; si funcionq , se convierte para mucha poblacion
Comparison:
Distinction between internal validity and external validity is essential for discerning between efficacy (effectiveness in controlled environments) and effectiveness (real-world application).
Clinical vs. Statistical Significance:
Clinical significance refers to the practical importance of a treatment effect, while statistical significance denotes whether the results obtained are likely due to chance.( meaningful for ghe ppl who participated in the study , the person se tiene que sentir mejor ensu vida , un cambio )
Statistical: happens by chance less than 5% of the time
Correlational Method
Definition:
The Relationship between variables is measured using a correlation coefficient.
Correlation Coefficient:
Indicates both direction and strength of the relationship between variables.
Ranges from -1.0 to 1.0, with positive and negative correlations:
Positive Correlation: Indicates that as one variable increases, the other also increases.
Negative Correlation: Indicates that as one variable increases, the other decreases.
0.1-0.3 weak
0.4-0.5 moderate
0.6-0.9 strong
Key Point:
"Correlation does not imply causation," emphasizing that a correlation between two variables does not mean one causes the other.
Example of Positive Correlation
Scenario:
Day-by-day tracking of cigarettes smoked per day vs. scores on an anxiety scale.
**Data Table: **
Day | # of Cigarettes Smoked/Day | Score on Anxiety Scale
--- | --- | ---
1 | 5 | 2
2 | 15 | 10
3 | 4 | 3
4 | 13 | 11
5 | 10 | 9
6 | 17 | 13
7 | 7 | 5
8 | 6 | 3
9 | 21 | 15
Visualization:
Graphical representation showing the correlation between the number of cigarettes smoked per day and anxiety scores.
Statistical Analysis:
Pearson's r coefficient: 0.97
Probability of occurrence by chance ( p < .05): Probability indicates that this high correlation is statistically significant, with a chance occurrence rate of less than 5%.
Further Example of Positive Correlation
Correlation between Final Grade and Attendance in Abnormal Psychology:
Data indicates a high positive correlation where:
Pearson's r coefficient: 0.66
Probability of this correlation occurring by chance: p < .05 (actual p value = .001)
Research Design Types
Cross-sectional Design:
Participants are assessed once for the specific variable under investigation, providing a snapshot of the data at one point in time.
Longitudinal Design:
Participants are assessed at least twice over a certain time interval, allowing researchers to observe changes over time.
Cohorts:
A cohort is defined as a group of people who share a common characteristic and move forward in time as a unit, beneficial for longitudinal research approaches.