Questions and Answers
What is correlation?
A measure of the extent to which two variables change together and thus of how well either variable predicts the other.
What is the correlation coefficient?
A statistical index of the relationship between two variables (from -1.0 to +1.0).
What is a scatterplot?
A graphed cluster of dots, each of which represents the values of two variables.
What is illusory correlation?
Signup and view all the answers
What is an experiment?
Signup and view all the answers
What is an experimental group?
Signup and view all the answers
What is a control group?
Signup and view all the answers
What is random assignment?
Signup and view all the answers
The closer a correlation coefficient gets to __ or __, the stronger the correlation.
Signup and view all the answers
Is 'The more children and youth used various media, the less happy they were with their lives' an example of positive or negative correlation?
Signup and view all the answers
Is 'The longer children were breast-fed, the greater their later academic achievement' an example of positive or negative correlation?
Signup and view all the answers
What is a point to remember about correlation and causation?
Signup and view all the answers
What is important to remember about random coincidences?
Signup and view all the answers
What is the difference between a correlational study and an experiment?
Signup and view all the answers
What is the placebo effect?
Signup and view all the answers
What is the purpose of random assignment?
Signup and view all the answers
What are three measures of central tendency?
Signup and view all the answers
What principles help decide if an observed difference is reliable?
Signup and view all the answers
What is the relative usefulness of the two measures of variation?
Signup and view all the answers
How do we know whether an observed difference can be generalized to other populations?
Signup and view all the answers
Which of the following is a measure of variation?
Signup and view all the answers
What statistical measure of central tendency is most affected by extreme scores?
Signup and view all the answers
What does a statistical significance of 5 percent indicate?
Signup and view all the answers
Descriptive statistics ___________, while inferential statistics ___________.
Signup and view all the answers
Explain the difference between descriptive and inferential statistics in research.
Signup and view all the answers
What is double-blind procedure?
Signup and view all the answers
What is the placebo effect?
Signup and view all the answers
What is the independent variable?
Signup and view all the answers
What is a confounding variable?
Signup and view all the answers
What is the dependent variable?
Signup and view all the answers
What is validity?
Signup and view all the answers
What are descriptive statistics?
Signup and view all the answers
What is a histogram?
Signup and view all the answers
What is mean?
Signup and view all the answers
What is mode?
Signup and view all the answers
What is median?
Signup and view all the answers
What is a skewed distribution?
Signup and view all the answers
What is range?
Signup and view all the answers
What is standard deviation?
Signup and view all the answers
What is a normal curve?
Signup and view all the answers
What are inferential statistics?
Signup and view all the answers
What is statistical significance?
Signup and view all the answers
What is an example of illusory correlation?
Signup and view all the answers
In an experiment, what are the independent and dependent variables when studying the impact of a drug on cancer?
Signup and view all the answers
How do you find the mean, median, and mode for the numbers 6, 7, 13, 15, 18, 21, 21, and 25?
Signup and view all the answers
Study Notes
Correlation and Its Measures
- Correlation refers to how two variables change together and predict each other’s behavior.
- The correlation coefficient quantifies the relationship between variables on a scale from -1.0 to +1.0.
- Scatterplots visually represent correlations, showcasing clusters of dots for two variables.
- Illusory correlations involve perceiving a relationship where none exists, often due to cognitive biases.
Experimentation Fundamentals
- Experiments manipulate one or more variables to observe effects on behavior or mental processes.
- Experimental groups receive the treatment, while control groups do not, serving as a comparison.
- Random assignment reduces pre-existing differences by allocating participants to groups by chance.
Correlation vs. Causation
- Correlation does not imply causation; relationships can exist without one causing the other.
- Coincidences can mislead individuals into believing in a correlation between unrelated events.
Types of Research Methods
- Correlational studies examine naturally occurring relationships, but experiments actively manipulate variables.
- Observational methods are descriptive, while correlational approaches assess prediction.
Research Design Components
- Placebo effects occur when an inert treatment influences behavior, demonstrating expectation's power.
- Double-blind procedures protect against bias by keeping both participants and researchers unaware of treatment allocations.
Central Tendency and Variation
- Measures of central tendency include mode (most frequent), mean (average), and median (midpoint).
- Variability in data can be measured through range (gap between highest and lowest) and standard deviation (how scores diverge from mean).
Statistical Principles
- Statistical significance indicates the likelihood that observed results occurred by chance, typically set at 5%.
- Inferential statistics allow researchers to make generalizations about populations based on sample data, while descriptive statistics summarize data characteristics.
Data Visualization and Distribution
- Histograms depict frequency distributions, showing how data points are spread within ranges.
- Normal curves illustrate distributions where most scores cluster around the mean, signifying symmetry.
Understanding Experimental Variables
- Independent variables are manipulated in experiments to observe effects on dependent variables.
- Confounding variables are external factors that could influence results if not controlled.
Graphical and Numerical Data Interpretation
- An example of strong correlation might be a coefficient of +.75 compared to +.30.
- Skewed distributions indicate asymmetrical data around an average, affecting the calculation of measures like mean and median.
Application of Research Findings
- Generalizability of research findings also depends on sample representation and observation variability.
- Example case studies can highlight concepts like illusory correlation in real-world scenarios.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge of key concepts from AP Psychology modules 6 and 7 with these flashcards. You'll encounter essential terms such as correlation, correlation coefficient, and scatterplot, along with their definitions. This is a great resource for reinforcing your understanding and preparing for exams.