**Select menu: Stats | Design | Generate a Fractional Factorial Design**

## Number of treatment factors

The number of treatment factors for the design.

## Treatment factor names

Provides a list of the treatment factor names to use in the generated design. The number of items in the list is controlled by the Number of treatment factors option. To change a name either click or double-click on the name in the list and rename it as required.

## Number of levels for all treatment factors

Specifies the number of levels. Each treatment factor must contain the same number of levels. The number of levels must be a prime number (e.g. 2, 3, 5, 7, 11) or 4.

## Number of units in each block

Specifies the number of the units in each block; this must be a power of the number of levels.

## Name of the sub-block factor

Specifies the name for the identifier for the sub-blocks.

## Pseudo-factors for ANOVA

Designs where the treatment factors have more than two levels may require pseudo-factors to be defined in order for them to be analysed by analysis of variance. This option can be used to specify the name of the pseudo-factors.

## Number of block for fractional factorial

The number of the block to form the fractional factorial. Alternatively, a zero can be supplied to take a block at random.

## Number of units in sub-blocks

Defines the size of the sub-blocks for a fractional factorial. This must be a power of the number of levels.

## Options

Specifies additional options for randomizing and displaying the design.

Randomize design | When selected, the design will be randomized, otherwise the units will be in standard order. You can set the seed for the randomization using the Randomization seed option. |

Display design in a spreadsheet | When selected, the resulting design will be put into a spreadsheet window. |

## Action Buttons

Run | Generate the design. |

Cancel | Close the menu without further changes. |

Options | Opens a dialog where additional options and settings can be specified for the designs. |

Defaults | Change the settings back to the default settings. Clicking the right mouse on this button produces a pop-up menu where you can choose to reset the fields using the currently stored defaults or the Genstat default settings. |

## Action Icons

Pin | Controls whether to keep the menu open when you click Run. When the pin is down , then the menu will remain open, otherwise when the pin is up , the menu will close. | |

Restore | Restore names into edit fields and default settings. | |

Clear | Clear all edit and list boxes. | |

Help | Help about this menu. |

## See Also

- Factorial design options dialog
- Generate a factorial design in blocks menu for generating full factorial designs
- Generate a standard design menu for generating general designs
- Generate a Design Efficient under ANCOVA menu
- Select Design for generating designs through a sequence of questions and answers
- AGFACTORIAL procedure in command mode