BA 260 Midterm

Chapter 7 & 8

Alternative Hypothesis

A statement that contradicts the null hypothesis and represents the conclusion the researcher is trying to support by refuting the null hypothesis, or showing that the null is not true.

Big Data

Large and complex data sets that require advanced computational methods for analysis.

Census

A study that collects data from every member of a population rather than a sample.

Central Limit Theorem

A statistical theorem stating that the sampling distribution of the sample mean approaches a normal distribution as the sample size increases.

Confidence Coefficient

The probability that a confidence interval contains the true population parameter.

Confidence Interval

A range of values within which the true population parameter is likely to fall with a specified confidence level.

Confidence Level

The probability that the confidence interval contains the population parameter, often expressed as a percentage.

Coverage Error

An error that occurs when some members of the population are not included in the sampling frame.

Degrees of Freedom

The number of values in a calculation that are free to vary, often used in statistical tests.

Frame

A list or representation of all elements in a population from which a sample is drawn.

Hypothesis Testing

A statistical procedure used to determine whether there is enough evidence to reject a null hypothesis.

Interval Estimate

An estimate of a population parameter given as a range of values rather than a single number.

Interval Estimation

The process of estimating a population parameter using an interval rather than a point estimate.

Level of Significance

The probability of rejecting a true hypothesis is denoted by alpha (α).

Margin of Error

The amount of error that is tolerated in statistical estimates is used to determine a confidence interval at a specified level of confidence.

Nonresponse Error

An error occurs when some individuals selected for a sample do not respond.

Non-Sampling Error

Errors in data collection that are not related to the process of selecting a sample, such as measurement errors or biases.

Null Hypothesis

A statement that there is no effect or no difference serves as the default assumption in hypothesis testing. Hypothesis Testing tries to refute this no-effect or no-difference statement; it's why we reject or fail to reject the null hypothesis.

One-Tailed Test

A hypothesis test where the alternative hypothesis specifies a direction (greater than or less than)

P-Value

The probability of obtaining a test statistic as extreme as the one observed, assuming the null hypothesis is true.

Parameter

A numerical characteristic of a population, such as a mean or proportion.

Point Estimate

A single value estimate of a population parameter derived from a sample.

Point Estimator

A statistic used to estimate a population parameter.

Practical Significance

The real-world importance of a statistical result, rather than statistical significance.

Random Sample

A sample in which every member of the population has an equal chance of being selected.

Random Variable

A variable that takes on different values due to chance.

Sample Statistic

A numerical summary of a sample, such as the sample mean or proportion.

Sampled Population

The population from which the sample is actually drawn.

Sampling Distribution

The probability distribution of a statistic based on repeated random samples.

Sampling Error

The error that arises from differences between a sample statistic and the population parameter.

Simple Random Sample

A sampling method where every possible sample of a given size has an equal chance of being chosen.

Standard Error

The standard deviation of a sampling distribution measures the precision of a sample estimate.

Standard Normal Distribution

A normal distribution with a mean of 0 and a standard deviation of 1.

Statistical Inference

The process of drawing conclusions about a population based on sample data.

T-Distribution

A probability distribution is used in hypothesis testing when the sample size is small and the population variance is unknown.

Target Population

The entire group a researcher is interested in studying.

Test Statistic

A value calculated from sample data used to decide whether to reject the null hypothesis.

T-Test

A statistical test used to compare sample means or regression coefficients.

Two-Tailed Test

A hypothesis test that considers both directions of an effect (greater than or less than).

Type I Error

Rejecting a true null hypothesis (false positive).