Lecture 4 Flashcards
What is the format of the upcoming test?
In-class, consisting of 50-60 multiple choice or multi-select questions.
No lecture afterwards; tests are not open book.
What are the main topics covered in the upcoming test?
- Clinical & experimental streams of psychology
- History & evolution of psychology
- Schools of psychology
- The scientific method
- Types of study designs
- Statistics
- Data analysis
What are descriptive statistics?
The most basic type of statistic that describes data mathematically.
Provides key insights about what the data looks like.
Define central tendency.
A single value that represents the ‘center’ or typical value of a dataset.
List the three common measures of central tendency.
- Mean
- Median
- Mode
What is the mean?
The arithmetic average of the scores in a distribution.
What is the median?
The score that falls exactly in the center of a distribution.
What is the mode?
The most frequent score in a distribution.
Why might the median or mode be preferred over the mean?
The average score may not always accurately describe data, especially in cases of extreme values.
What does variability refer to?
How much the scores in a data set vary from each other and from the mean.
What is the most common measure of variability?
Standard Deviation.
Define standard deviation.
An index of the amount of variability in a set of data.
What is a normal distribution?
A symmetrical, bell-shaped curve representing the pattern in which many human characteristics are dispersed in the population.
What percentage of scores fall within one standard deviation of the mean in a normal distribution?
68%.
What is a percentile?
The percentage of people who fall at or below a particular score.
What is skewness in statistics?
When most scores do not fall near the average, leading to an asymmetrical distribution.
What is a ceiling effect?
A limitation where data points cluster at the upper end of a scale, often leading to negative skewness.
What is a floor effect?
A limitation where data points cluster at the lower end of a scale, often leading to positive skewness.
What is a hypothesis in research?
A formal statement predicting an effect or difference.
What are the two parts of a hypothesis?
- H0 (Null Hypothesis): No effect or difference
- H1 (Research Hypothesis): Presence of an effect or difference
What does Null Hypothesis Significance Testing (NHST) involve?
A statistical method to determine whether observed data significantly differ from a baseline assumption.
What is a p-value?
A probability value indicating the likelihood that observed results were due to random chance.
What is a Type I Error?
When a true effect does not exist, but the study detects an effect (false positive).
What is a Type II Error?
When a true effect exists, but the study fails to detect it (false negative).
What is considered statistically significant?
A result with a p-value less than 0.05.
What are the two general outcomes of statistical analyses?
- Statistically significant
- Non-significant
What does correlation measure?
The degree of association or relationship between two variables.
What is Pearson’s r?
A statistical measure of the relationship between two variables.
What does a positive correlation indicate?
When one variable tends to increase as the other increases.
What does a negative correlation indicate?
When one variable tends to increase as the other decreases.
What is spurious correlation?
When two variables appear to be related, but their correlation is due to coincidence or the influence of a third variable.
What statistical test is used to compare differences between two groups?
T-Test.
What statistical test is used to compare differences between three or more groups?
ANOVA.
