Texas Instruments TI-83 PLUS - Manual (Page 358)

TI-83 Plus Statistics 355
Note: To set DiagnosticOn or DiagnosticOff from the home screen, press y
N , and then select the instruction for the mode you want. The instruction
is pasted to the home screen. Press Í to set the mode.
When DiagnosticOn is set, diagnostics are displayed with the results
when you execute a regression model.
When DiagnosticOff is set, diagnostics are not displayed with the results
when you execute a regression model.