Creating and Estimating Linear Models on Tuva
Lesson
In this tutorial, students explore the Dinosaurs dataset to learn how to use the Modeling Card on Tuva. They then learn how to graph linear and nonlinear functions in the context of real data. ![]720
In this tutorial, you will explore the Dinosaurs dataset to learn how to use the Modeling Card on Tuva to graph linear and nonlinear functions in the context of real data. ![]720 Introduction: If the form of the graph suggests an underlying linear relationship, then a straight line can be used to model the relationship. !--- Recall: The equation for any straight line is: y = mx + b or y = k*x. ---!{border-color:#008000;text-align:left;} Both these equations describe linear relationships. The only difference is that the second one is also a direct proportion. Tuva helps you build your understanding of linear models by providing a buffet of tools & features ranging from simple to complex. In this tutorial, you will read about the movable line and learn the steps for fitting linear data using this tool. The movable line is useful for eyeball estimation of a linear fit. It works quite similar to how you draw a best-fit line on paper except you can flexibly stretch and drag it around. ![]700 The process of fitting bivariate linear data with a movable line is fairly simple. Here are the steps: Step 1: Create a Scatter Plot and Add the Movable Line You can drag a numerical attribute to each of the x- and y-axes to create a scatter plot. Next, you can add the :ti[movable-line] from the :ti[model-data] menu in the toolbar. ![]700 Step 2: Adjust the Movable Line You can drag the line by its middle to translate the line (shift up, down, left, or right). This changes the intercept. ![]700 Step 2: Adjust the Movable Line (Contd.) You can drag by the handles at either end to rotate the line or change the slope. ![]700 Step 2: Adjust the Movable Line (Contd.) You can drag either handle along the slope of the line to stretch the line. ![]700 Step 3: Find the Right Fit The parameters of the line get updated dynamically as you drag the movable line in search of a good fit. You can tweak the line until it seems to fit the data. The fitted graph will look somewhat like this: ![]700 Step 4: Read the Equation of the Line You can hover over the line to read its equation. You can also pull up the :ti[ti-summary-view] to read the equation of the line. ![]700 In the interactive tutorial that follows, you will explore two datasets to learn fitting linear data with the Movable line. You will also learn to use additional features around the Movable line to make your analysis more exciting. A few of these features are: Changing the color of the movable line; Displaying the equation of the line in a label; Adding multiple movable lines on the graph; Adding multiple movable lines to a dual axis graph; Pulling up the Summary View to compare the equations of two movable lines. Click on Next to get started.
Topics and standards: Line Of Best Fit, Linear Relationships, Tutorial