Invalid Sample

For survey data, some responses may be unreliable (e.g., selecting the same option for all questions). In such cases, the Invalid Sample function in SPSSAU can be used. The instructions are as follows:

Select the 'title'. Use ctrl or shift to select multiple titles for batch processing.

There are two criteria for identifying invalid samples: 'Same Number' and 'Missing Ratio', as shown below:

• Same Number: If a selected title contains the same value for a set percentage (e.g., 70%), the sample is marked as invalid. This threshold is user-defined.
• Missing Ratio: If a selected title contains missing values for a set percentage (e.g., 70%), the sample is marked as invalid. This threshold is also user-defined.
• 'Mark New Title': SPSSAU will generate a new title (e.g., 'Invalid_****_****') to indicate whether a sample is invalid.
• 'Delete Invalid Samples': If invalid samples are detected, SPSSAU will directly delete them.