Step 3 Apply Distributions in Visual Basic .NET
Step 3 Apply Distributions Code39 Generation In VB.NET Using Barcode creation for .NET framework Control to generate, create Code39 image in .NET applications. www.OnBarcode.comCode 3/9 Decoder In Visual Basic .NET Using Barcode reader for .NET framework Control to read, scan read, scan image in .NET applications. www.OnBarcode.comThere are numerous mathematical models for these types of distributions. Four of these models cover the overwhelming majority of user delay scenarios: Linear or uniform distribution Normal distribution Negative exponential distribution Double hump normal distribution Making Barcode In VB.NET Using Barcode creation for VS .NET Control to generate, create bar code image in VS .NET applications. www.OnBarcode.comScanning Bar Code In Visual Basic .NET Using Barcode recognizer for VS .NET Control to read, scan read, scan image in .NET applications. www.OnBarcode.comLinear or Uniform Distribution
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Double Hump Normal Distribution
The double hump normal distribution creates a distribution similar to that shown in the graph below. To understand when this distribution would be used, consider the first time you visit a Web page that has a large amount of text. On that first visit, you will probably want to read the text, but the next time you might simply click through that page on the way to a page located deeper in the site. This is precisely the type of user behavior this distribution represents. The figure below shows that 60 percent of the users who view this page spend about 8 seconds on the page scanning for the next link to click, and the other 40 percent of the users actually read the entire page, which takes about 45 seconds. You can see that both humps are normal distributions with different minimum, maximum, and standard deviation values. Figure 13.6 Double Hump Normal Distribution To implement this pattern, simply write a snippet of code to generate a number between 1 and 100 to represent a percentage of users. If that number is below a certain threshold (in the graph above, below 61), call the normal distribution function with the parameters to generate delays with the first distribution pattern. If that number is at or above that threshold, call the normal distribution function with the correct parameters to generate the second distribution pattern.

