#### Do you want to… look at a relationship among data points in a two variables?

*Bobbi is looking at the relationship between soil pH and plant growth. He hypothesizes that higher pH should result in less plant growth…*

### Scatter Plots

#### Often times in math and science data exists in two dimensions – time vs. height, precipitation vs. vegetative growth, etc. A scatter plot is a powerful tool to visually demonstrate relationships among order pairs in two dimensional data.

#### This video is a crash course is scatter plots, trend lines, correlation, and linear regression using Excel and NetLogo. This file contains the NetLogo model and excel file produced.

#### This video demonstrates how to create scatter plots using plot.ly. Please note that plot.ly has recently upgraded to plot.ly 2.0 so the video might be slightly out of date.

#### This video demonstrates how to use Excel to create scatterplots as well as bar graphs. This video demonstrates how to generate data using NetLogo, export that data to Excel, plot a scatterplot, and select the most appropriate trend line using correlation.

#### This Powerpoint contains a great lesson idea to use with students that uses a Heart Rate Model and corresponding activity to introduce scatter plots. If you skip to slide 34 you’ll find a lesson summary.

### Trend Lines

#### Trend lines allow one to approximate the relationship between data points in two dimensional space. A trend line is a model which can be used to predict the behavior of a dependent variable with changes made to an independent variable.

#### This video is a crash course is scatter plots, trend lines, correlation, and linear regression using Excel and NetLogo. This file contains the NetLogo model and excel file produced.

#### This video demonstrates how to create scatter plots using plot.ly. Please note that plot.ly has recently upgraded to plot.ly 2.0 so the video might be slightly out of date.

#### The Powerpoint used before with the Heart Rate Model can also be used to demonstrate trend lines. If you skip to slide 34 you’ll find a lesson summary.

### Correlation

#### Correlation is the measure of both the direction and strength of the relationship between the two variables in two dimensions.

#### This video is a crash course is scatter plots, trend lines, correlation, and linear regression using Excel and NetLogo. This file contains the NetLogo model and excel file produced.

#### This video demonstrates how to create scatter plots using plot.ly. Please note that plot.ly has recently upgraded to plot.ly 2.0 so the video might be slightly out of date.

#### The Powerpoint used before with the Heart Rate Model can also be used to demonstrate correlation and regression. If you skip to slide 34 you’ll find a lesson summary.

### Linear Regression

#### Linear Regression is a statistical tool used to extract a linear function approximating the relationship between two variables. The goal is to produce a relationship with strong correlation in order to use that function as a predictive model.

### Exponential Regression

#### Many real world phenomena follow exponential growth or decay models.

#### This video shows a NetLogo example which approximately fits an exponential model. Additionally, the video demonstrates how to extract data into Excel to produce an exponential function approximating the relationship and using the model as a predictive tool. You can download the NetLogo model and Excel file here.

### Logistic Behavior

#### Many real world phenomena follow a logistic behavior pattern.

#### This video helps to demonstrate logistic behavior in a few scientific contexts. You can find the NetLogo and Excel files here. This stats blog article also describes the phenomena.

#### The Powerpoint used before with side by side box and whisker plots will result in a logistic relationship between density and burn rate. If you skip to slide 20 you’ll find a lesson summary.