SledgeHammer

SledgeHammer is a flexible piece of software that can run over datasets in a variety of formats and produce DDI Lifecycle compliant metadata. Its flexibility in terms of formats and operating systems was of benefit it to the project. The studies involved each have different IT arrangements and software preferences, so this was an important feature. Sledgehammer can be run programmatically across a large number of data sets at once, making it very efficient.

The CLOSER project has made use of Sledgehammer to generate metadata for data. This off the shelf software has a large number of formats covered, including all three major operating systems. It generates DDI Lifecycle (3.2) compliant metadata from the data files themselves, including:

• Variable name

• Variable label (descriptor)

• Summary statistics

  • Frequency

  • Valid and invalid

  • Mean and mode

  • Standard deviation

These are the only items in the platform. The original data sets are held and processed by the host study to ensure data protection requirements are met. 

This software is no longer supported. MTNA has provided an update and a new license for CLOSER studies to use. This software will be replaced by open source software Extract2DDI

Known Issues:

• Long text strings > 255 characters should be truncated. These strings are not supported by the SPSS format properly so will lead to spurious errors in the output, and will not generate any metadata other than variable name and label in any case.

• Variables with a large numbers of decimal places. Please format data in a way that is useful, e.g. truncated/rounded to a set number of digits e.g. 4. NB just changing the display format of the variable does not alter the no. of decimal places on the data.

• Variables names VAR00001, VAR00002 etc indicate that duplicate variables have been merged in error.