College

Empirical probability is estimated from what actually happens in observed trials, while theoretical probability is calculated from a model of possible outcomes. The difference is that one is based on collected results and the other on assumptions about how an experiment works. What Probability Means in a Statistics Course Probability describes how likely an event […]

Correlation measures the direction and strength of an association between two variables; regression models how an outcome changes in relation to one or more explanatory variables. Correlation summarizes a relationship without assigning the variables distinct roles, while regression specifies a response and predictors so it can estimate or predict the response. What Correlation Measures Correlation

Covariance measures whether two variables tend to move together, while correlation measures the strength and direction of that relationship on a standardized scale. Correlation is therefore easier to compare across pairs of variables, whereas covariance retains the variables’ measurement units. What Covariance Measures Covariance describes how two variables vary together. If values of one variable

Accuracy is how close a measurement or result is to the true or accepted value; validity is whether a measurement or method actually captures what it is meant to measure. A result can be accurate without being valid for a particular question, and a measure can be valid in concept yet produce inaccurate results when

Accuracy is how close a measurement is to the true or accepted value; precision is how closely repeated measurements agree with one another. A set of results can be accurate, precise, both, or neither, so the terms describe different qualities of data rather than two words for the same thing. Why Accuracy and Precision Matter

Continental drift is the idea that continents have moved across Earth’s surface over geological time; plate tectonics is the broader, modern theory that explains how the entire outer shell of Earth moves and changes. Continental drift is an important part of the story, but plate tectonics explains not only shifting continents but also seafloor spreading,

Variance and standard deviation both describe how spread out data values are around their mean. The difference is that variance measures spread in squared units, while standard deviation is the square root of variance and therefore uses the same units as the original data. What Variance and Standard Deviation Mean In statistics, a measure of

Speed tells you how fast an object moves; velocity tells you how fast it moves and in what direction. Both describe motion, but speed is a scalar quantity, while velocity is a vector quantity. Why the Distinction Matters In everyday conversation, people often use “speed” and “velocity” as though they mean the same thing. In

Speed tells you how fast an object is moving; acceleration tells you how quickly its velocity is changing. An object can have high speed with no acceleration, or accelerate while moving slowly, because speed and acceleration describe different aspects of motion. What Speed Means Speed is the distance an object travels per unit of time.

Mass wasting is the downslope movement of rock, soil, or sediment under the direct influence of gravity. Mass movement is often used as a synonym for mass wasting, although some textbooks use it as a broader term for gravity-driven movement that can include material moving downslope or deforming in place. Why the Terms Can Seem