Statistics How To

Statistics Definitions > Berkson’s paradox (also known as Berkson’s fallacy or Berkson’s bias) is the counter-intuitive idea that events which seem to be correlated actually are not. Take two events, A and B, which are completely independent events (for example, lung cancer and diabetes). If a study selects for both the presence of A (lung … Read more

Probability and Statistics > Best Calculator for Statistics What is the Best Calculator for Statistics? Trying to choose the best calculator for statistics? You have many models to choose from. As of now, the TI-83, TI-86 and TI-89 are the commonest models that are widely used. A few other models by HP, Canon and others … Read more

Statistics Definitions > Process capability analysis is a set of tools used to find out how well a given process meets a set of specification limits. In other words, it measures how well a process performs. In practice, it compares the distribution of sample values—representing the process outcome—to the specification limits, which are the limits … Read more

Statistics Definitions > What is an Observation in Statistics? The term “observation” can have slightly different meanings, depending on where you’re using it. General Meaning of Observation in Statistics An observation in statistics is a value of something of interest you’re measuring or counting during a study or experiment: a person’s height, a bank account … Read more

Regression Analysis > Trend analysis quantifies and explains trends and patterns in a “noisy” data over time. A “trend” is an upwards or downwards shift in a data set over time. In economics, “trend analysis” usually refers to analysis on past trends in market trading; it allows you to predict what might happen to the … Read more

Time Series Analysis > Exponential Smoothing Contents: What is Exponential Smoothing? Exponential Smoothing in Excel 2016-2013 What is Exponential Smoothing? Exponential smoothing of time series data assigns exponentially decreasing weights for newest to oldest observations. In other words, the older the data, the less priority (“weight”) the data is given; newer data is seen as … Read more

Confidence intervals > “Z-interval” could refer to either: A specific type of confidence interval (see below), or A TI-83 calculator option to find a confidence interval for the mean using the Z Interval. If you’re using the TI-83, see this article on confidence intervals for step by step TI-83 Z Interval instructions. You may want … Read more

Descriptive Statistics > How to Choose Bin Sizes in Statistics Contents:

Statistics Definitions > Ratios and Rates Ratios and Rates: Contents (click to skip to that section): Ratio Definition Rate Definition Ratio Definition A ratio is a comparison of two numbers. It can be written in many ways. For example, the ratio of 5 to 9 can be expressed as: 5 to 9 5 out of … Read more

Statistics Definitions > Paired data is where natural matching or coupling is possible. Generally this would be data sets where every data point in one independent sample would be paired—uniquely—to a data point in another independent sample. This might be because they come from the same observational unit; the same individual, or the same location. … Read more