Statistics for the Behavioral and Social Sciences: A Brief Course

These flashcards cover key concepts from statistics specifically focusing on behavioral and social sciences, including definitions and explanations of statistical terms and methods.

What are the two main branches of statistics?

Descriptive statistics and Inferential statistics.

What do descriptive statistics do?

They summarize, organize, and describe data from a research study.

What is the purpose of inferential statistics?

To draw conclusions and make inferences based on scores collected in a research study.

Define 'population' in the context of statistics.

The entire set of things of interest; for example, all undergraduate students at a university.

What is a 'sample' in statistics?

A part of the population about which information is actually gathered.

What distinguishes categorical variables from numeric variables?

Categorical variables have values that are names or categories, while numeric variables have values that are numbers.

What is the average in statistics commonly referred to?

The mean.

How is variance defined in statistics?

A measure of how spread out a set of scores are.

What does a positive correlation indicate?

As one variable increases, the other variable also tends to increase.

What does a negative correlation indicate?

As one variable increases, the other variable tends to decrease.

What is the null hypothesis in hypothesis testing?

A statement that there is no effect or difference, it is the assumption that any observed effect is due to chance.

What is the purpose of calculating the standard deviation in statistics?

To describe the spread of scores around the mean.

What is a Type I error?

Rejecting the null hypothesis when it is actually true.

What is a Type II error?

Not rejecting the null hypothesis when it is actually false.

What is the main goal of a t-test?

To compare the means of groups to see if they are significantly different from each other.

What is ANOVA used for?

To test differences between the means of three or more groups.

What are post-hoc tests used for in ANOVA?

To determine which specific group means are significantly different from each other after finding a significant F ratio.

What is the significance level (alpha) commonly used in hypothesis testing?

Typically set at 0.05, meaning researchers accept a 5% chance of making a Type I error.

In hypothesis testing, what does rejecting the null hypothesis imply?

There is evidence to support the alternative hypothesis.

Define 'power' in the context of hypothesis testing.

The probability that a test will correctly reject a false null hypothesis.

What does a two-tailed test imply?

That deviations in both directions (higher or lower than the null hypothesis) are taken into account.

Why is random sampling important in statistical research?

It helps ensure the sample is representative of the population, reducing bias and improving generalizability.

What is the central limit theorem?

States that the distribution of sample means approaches a normal distribution as the sample size increases.

What is the formula for calculating a Z-score?

Z = (X - μ) / σ, where X is a raw score, μ is the mean, and σ is the standard deviation.

How do you interpret a Z-score of 2?

The score is two standard deviations above the mean.

What does a confidence interval represent?

A range of values that likely contains the population parameter with a specified probability.

In a hypothesis test, what does the p-value indicate?

The probability of observing the data, or something more extreme, if the null hypothesis is true.

When should the null hypothesis be rejected?

When the p-value is less than the significance level (typically 0.05).