Introduction The Z-test is a simple tool for hypothesis testing that can be used to identify whether a mean result, when compared to a larger set is statistically significant when the larger set is a normal distribution. Many datasets (for instance population height, test scores, etc.) have normal distributions. If you’re unsure whether your dataset has…
Category: Math and Statistics
Statistical Coding and Classification
Introduction to Classification Oftentimes when performing research or intelligence analysis, the first step is to classify the available data. Classification provides a number of benefits that make later analysis easier. For one, they allow you to infer other qualities based on all items in a class sharing similar properties. For instance, knowing that mammals have…
Predicting Your Helpline Call Answer Rate
One role of helpline managers is to manage their workers so that they can answer the most calls possible within the available resources. Even helplines that run 24-hours and have 100% coverage can’t answer 100% of the calls that come in if they have more callers calling in than workers available. Using a system like Chronicall…
Least-Squares Regression
Regression is a technique used to predict future values based on known values. For instance, linear regression allows us to predict what an unknown Y value will be, given a series of known X and Y’s, and a given X value. Given the following, it’s easy to see the pattern. But assuming no obvious pattern…
Correlation (Calculating Pearson’s r)
Correlation refers to the idea that two variables (x and y) impact each other. For instance, the grades in a statistics class may be related to, or correlated with the amount of time those students study. As study time goes up, grades go up. This would be a positive correlation. On the other hand, as…